2.1 Important Dosage and Administration Instructions

Administer Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension by the oral route only. Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension can be taken with or without food. Shake well before using. Do not mix Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with other liquids or medicines. Mixing may change how Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension works.

Always use an accurate milliliter measuring device when administering Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension to ensure that the dose is measured and administered accurately. A household teaspoon is not an accurate measuring device and could lead to overdosage [ ]. For prescriptions where a measuring device is not provided, a pharmacist can provide an appropriate measuring device and can provide instructions for measuring the correct dose. Do not overfill. Rinse the measuring device with water after each use. Always use an accurate milliliter measuring device when administering Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension to ensure that the dose is measured and administered accurately. A household teaspoon is not an accurate measuring device and could lead to overdosage [ see Warnings and Precautions (5.5)]. For prescriptions where a measuring device is not provided, a pharmacist can provide an appropriate measuring device and can provide instructions for measuring the correct dose. Do not overfill. Rinse the measuring device with water after each use.

Advise patients not to increase the dose or dosing frequency of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension because serious adverse events such as respiratory depression may occur with overdosage [ ]. The dosage of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension should not be increased if cough fails to respond; an unresponsive cough should be reevaluated for possible underlying pathology [ ]. Advise patients not to increase the dose or dosing frequency of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension because serious adverse events such as respiratory depression may occur with overdosage [ see Warnings and Precautions (5.2) and Overdosage (10)]. The dosage of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension should not be increased if cough fails to respond; an unresponsive cough should be reevaluated for possible underlying pathology [ see Dosage and Administration (2.3) and Warnings and Precautions (5.4)].

2.2 Recommended Dosage

Adults 18 years of age and older: 5 mL every 12 hours as needed, not to exceed 2 doses (10 mL) in 24 hours

2.3 Monitoring, Maintenance, and Discontinuation of Therapy

Prescribe Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension for the shortest duration that is consistent with individual patient treatment goals [ see Warnings and Precautions (5.1)].

Monitor patients closely for respiratory depression, especially within the first 24-72 hours of initiating therapy [ ] Monitor patients closely for respiratory depression, especially within the first 24-72 hours of initiating therapy [ see Warnings and Precautions (5.2)] .

Reevaluate patients with unresponsive cough in 5 days or sooner for possible underlying pathology, such as foreign body or lower respiratory tract disease [ ]. If a patient requires a refill, reevaluate the cause of the cough and assess the need for continued treatment with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, the relative incidence of adverse reactions, and the development of addiction, abuse, or misuse [ ]. Reevaluate patients with unresponsive cough in 5 days or sooner for possible underlying pathology, such as foreign body or lower respiratory tract disease [ see Warnings and Precautions (5.4)]. If a patient requires a refill, reevaluate the cause of the cough and assess the need for continued treatment with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, the relative incidence of adverse reactions, and the development of addiction, abuse, or misuse [ see Warnings and Precautions (5.1)].

Do not abruptly discontinue Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in a physically-dependent patient [ ]. When a patient who has been taking Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension regularly and may be physically dependent no longer requires therapy with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, taper the dose gradually, by 25% to 50% every 2 to 4 days, while monitoring carefully for signs and symptoms of withdrawal. If the patient develops these signs or symptoms, raise the dose to the previous level and taper more slowly, either by increasing the interval between decreases, decreasing the amount of change in dose, or both. Do not abruptly discontinue Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in a physically-dependent patient [ see Drug Abuse and Dependence (9.3)]. When a patient who has been taking Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension regularly and may be physically dependent no longer requires therapy with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, taper the dose gradually, by 25% to 50% every 2 to 4 days, while monitoring carefully for signs and symptoms of withdrawal. If the patient develops these signs or symptoms, raise the dose to the previous level and taper more slowly, either by increasing the interval between decreases, decreasing the amount of change in dose, or both.

5.1 Addiction, Abuse, and Misuse

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension contains hydrocodone, a Schedule II controlled substance. As an opioid, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension exposes users to the risks of addiction, abuse, and misuse [ see Drug Abuse and Dependence (9)] , which can lead to overdose and death [ see Overdosage (10)] . Reserve Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension for use in adult patients for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made. Assess each patient’s risk prior to prescribing Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, prescribe Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension for the shortest duration that is consistent with individual patient treatment goals , monitor all patients regularly for the development of addiction or abuse, and refill only after reevaluation of the need for continued treatment.

Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Addiction can occur at recommended dosages and if the drug is misused or abused. Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression).Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Addiction can occur at recommended dosages and if the drug is misused or abused. Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression).

Opioids are sought by drug abusers and people with addiction disorders and are subject to criminal diversion. Consider these risks when prescribing or dispensing Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity and advising the patient on the proper disposal of unused drug [ ]. Contact local state professional licensing board or state controlled substances authority for information on how to prevent and detect abuse or diversion of this product. Opioids are sought by drug abusers and people with addiction disorders and are subject to criminal diversion. Consider these risks when prescribing or dispensing Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity and advising the patient on the proper disposal of unused drug [ see Patient Counseling Information (17)]. Contact local state professional licensing board or state controlled substances authority for information on how to prevent and detect abuse or diversion of this product.

5.2 Life-Threatening Respiratory Depression

Serious, life-threatening, or fatal respiratory depression has been reported with the use of opioids, including hydrocodone, one of the active ingredients in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Hydrocodone produces dose-related respiratory depression by directly acting on the brain stem respiratory center that controls respiratory rhythm and may produce irregular and periodic breathing. Respiratory depression, if not immediately recognized and treated, may lead to respiratory arrest and death. Management of respiratory depression includes discontinuation of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, close observation, supportive measures, and use of opioid antagonists (e.g. naloxone), depending on the patient’s clinical status [ see Overdosage (10)].  Carbon dioxide (CO 2) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.

While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, the risk is greatest during the initiation of therapy, when Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is used concomitantly with other drugs that may cause respiratory depression [ ], in patients with chronic pulmonary disease or decreased respiratory reserve, and in patients with altered pharmacokinetics or altered clearance (e.g. elderly, cachectic, or debilitated patients) [ ]. While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, the risk is greatest during the initiation of therapy, when Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is used concomitantly with other drugs that may cause respiratory depression [ see Warnings and Precautions (5.8)], in patients with chronic pulmonary disease or decreased respiratory reserve, and in patients with altered pharmacokinetics or altered clearance (e.g. elderly, cachectic, or debilitated patients) [ see Warnings and Precautions (5.4)].

To reduce the risk of respiratory depression, proper dosing of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is essential [ ]. Monitor patients closely, especially within the first 24-72 hours of initiating therapy or when used in patients at higher risk. To reduce the risk of respiratory depression, proper dosing of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is essential [ see Dosage and Administration (2.1), Warnings and Precautions (5.5)]. Monitor patients closely, especially within the first 24-72 hours of initiating therapy or when used in patients at higher risk.

Overdose of hydrocodone in adults has been associated with fatal respiratory depression, and the use of hydrocodone in children younger than 6 years of age has been associated with fatal respiratory depression when used as recommended. Accidental ingestion of even one dose of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, especially by children, can result in respiratory depression and death.Overdose of hydrocodone in adults has been associated with fatal respiratory depression, and the use of hydrocodone in children younger than 6 years of age has been associated with fatal respiratory depression when used as recommended. Accidental ingestion of even one dose of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, especially by children, can result in respiratory depression and death.

5.3 Risks of Use in Pediatric Populations

Children are particularly sensitive to the respiratory depressant effects of hydrocodone [ see Warnings and Precautions (5.2)]. Because of the risk of life-threatening respiratory depression and death, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is contraindicated in children less than 6 years of age [ see Contraindications (4)].

Use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in children also exposes them to the risks of addiction, abuse, and misuse [ ] which can lead to overdose and death [ ] Because the benefits of symptomatic treatment of cough associated with allergies or the common cold do not outweigh the risks of use of hydrocodone in pediatric patients, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is not indicated for use in patients younger than 18 years of age [ ].  Use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in children also exposes them to the risks of addiction, abuse, and misuse [ see Drug Abuse and Dependence (9)] , which can lead to overdose and death [ see Warnings and Precautions (5.1), Overdosage (10)] . Because the benefits of symptomatic treatment of cough associated with allergies or the common cold do not outweigh the risks of use of hydrocodone in pediatric patients, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is not indicated for use in patients younger than 18 years of age [ see Indications (1), Use in Specific Populations (8.4)].

5.4 Risks of Use in Other At-Risk Populations

Unresponsive Cough

The dosage of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension should not be increased if cough fails to respond; an unresponsive cough should be reevaluated in 5 days or sooner for possible underlying pathology, such as foreign body or lower respiratory tract disease [ ]. The dosage of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension should not be increased if cough fails to respond; an unresponsive cough should be reevaluated in 5 days or sooner for possible underlying pathology, such as foreign body or lower respiratory tract disease [ see Dosage and Administration (2.3)].

Asthma and Other Pulmonary Disease

The use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients with acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment is contraindicated [ ]. The use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients with acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment is contraindicated [ see Contraindications (4)].

Opioid analgesics and antitussives, including hydrocodone, one of the active ingredients in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, should not be used in patients with acute febrile illness associated with productive cough or in patients with chronic respiratory disease where interference with ability to clear the tracheobronchial tree of secretions would have a deleterious effect on the patient’s respiratory function.Opioid analgesics and antitussives, including hydrocodone, one of the active ingredients in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, should not be used in patients with acute febrile illness associated with productive cough or in patients with chronic respiratory disease where interference with ability to clear the tracheobronchial tree of secretions would have a deleterious effect on the patient’s respiratory function.

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension-treated patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or pre-existing respiratory depression are at increased risk of decreased respiratory drive including apnea, even at recommended dosages of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension [ ] Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension-treated patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or pre-existing respiratory depression are at increased risk of decreased respiratory drive including apnea, even at recommended dosages of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension [ see Warnings and Precautions (5.2)] .

: Life-threatening respiratory depression is more likely to occur in elderly, cachectic, or debilitated patients because they may have altered pharmacokinetics or altered clearance compared to younger, healthier patients [ ].  Elderly, Cachectic, or Debilitated Patients: Life-threatening respiratory depression is more likely to occur in elderly, cachectic, or debilitated patients because they may have altered pharmacokinetics or altered clearance compared to younger, healthier patients [ see Warnings and Precautions (5.2)].

Because of the risk of respiratory depression, avoid the use of opioid antitussives, including Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients with compromised respiratory function, patients at risk of respiratory failure, and in elderly, cachectic, or debilitated patients. If Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is prescribed, monitor such patients closely, particularly when initiating Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension and when Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is given concomitantly with other drugs that depress respiration [ ]. Because of the risk of respiratory depression, avoid the use of opioid antitussives, including Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients with compromised respiratory function, patients at risk of respiratory failure, and in elderly, cachectic, or debilitated patients. If Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is prescribed, monitor such patients closely, particularly when initiating Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension and when Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is given concomitantly with other drugs that depress respiration [ see Warnings and Precautions (5.8)].

5.5 Risk of Accidental Overdose and Death due to Medication Errors

Dosing errors can result in accidental overdose and death. To reduce the risk of overdose and respiratory depression, ensure that the dose of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is communicated clearly and dispensed accurately [ see Dosage and  Administration (2.1)].

Advise patients to always use an accurate milliliter measuring device when measuring and administering Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Inform patients that household teaspoon is not an accurate measuring device and such use could lead to overdosage and serious adverse reactions [ ]. For prescriptions where a measuring device is not provided, a pharmacist can provide an appropriate calibrated measuring device and can provide instructions for measuring the correct dose. Advise patients to always use an accurate milliliter measuring device when measuring and administering Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Inform patients that household teaspoon is not an accurate measuring device and such use could lead to overdosage and serious adverse reactions [ see Overdosage (10)]. For prescriptions where a measuring device is not provided, a pharmacist can provide an appropriate calibrated measuring device and can provide instructions for measuring the correct dose.

5.6 Activities Requiring Mental Alertness: Risks of Driving and Operating Machinery

Hydrocodone and chlorpheniramine, two of the active ingredients in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, may produce marked drowsiness and impair the mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery. Advise patients to avoid engaging in hazardous tasks requiring mental alertness and motor coordination after ingestion of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Avoid concurrent use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with alcohol or other central nervous system depressants because additional impairment of central nervous system performance may occur [ see Warnings and Precautions (5.8).

5.7 Risks from Concomitant Use or Discontinuation of Cytochrome P450 3A4 Inhibitors and Inducers

Concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with a CYP3A4 inhibitor, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), and protease inhibitors (e.g., ritonavir), may increase plasma concentrations of hydrocodone and prolong opioid adverse reactions, which may cause potentially fatal respiratory depression [ see Warnings and Precautions (5.2)], particularly when an inhibitor is added after a stable dose of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is achieved. Similarly, discontinuation of a CYP3A4 inducer, such as rifampin, carbamazepine, and phenytoin, in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension-treated patients may increase hydrocodone plasma concentrations and prolong opioid adverse reactions.

Concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with CYP3A4 inducers or discontinuation of an CYP3A4 inhibitor could decrease hydrocodone plasma concentrations, decrease opioid efficacy or, possibly, lead to a withdrawal syndrome in a patient who had developed physical dependence to hydrocodone.Concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with CYP3A4 inducers or discontinuation of an CYP3A4 inhibitor could decrease hydrocodone plasma concentrations, decrease opioid efficacy or, possibly, lead to a withdrawal syndrome in a patient who had developed physical dependence to hydrocodone.

Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients who are taking a CYP3A4 inhibitor or inducer. If concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with a CYP3A4 inhibitor or inducer is necessary, monitor patients for signs and symptoms that may reflect opioid toxicity and opioid withdrawal [ ]. Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients who are taking a CYP3A4 inhibitor or inducer. If concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with a CYP3A4 inhibitor or inducer is necessary, monitor patients for signs and symptoms that may reflect opioid toxicity and opioid withdrawal [ see Drug Interactions ( 7.2, 7.3) ].

5.8 Risks from Concomitant Use with Benzodiazepines or other CNS Depressants

Concomitant use of opioids, including Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, with benzodiazepines, or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Because of these risks, avoid use of opioid cough medications in patients taking benzodiazepines, other CNS depressants, or alcohol [ see Drug Interactions ( 7.1, 7.5) ].

Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioids alone. Because of similar pharmacologic properties, it is reasonable to expect similar risk with concomitant use of opioid cough medications and benzodiazepines, other CNS depressants, or alcohol.Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioids alone. Because of similar pharmacologic properties, it is reasonable to expect similar risk with concomitant use of opioid cough medications and benzodiazepines, other CNS depressants, or alcohol.

Advise both patients and caregivers about the risks of respiratory depression and sedation if Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is used with benzodiazepines, alcohol, or other CNS depressants [ ] Advise both patients and caregivers about the risks of respiratory depression and sedation if Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is used with benzodiazepines, alcohol, or other CNS depressants [ see Patient Counseling Information (17)] .

Patients must not consume alcoholic beverages, or prescription or non-prescription products containing alcohol, while on Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension therapy. The co-ingestion of alcohol with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may result in increased plasma levels and a potentially fatal overdose of hydrocodone [ ].  Patients must not consume alcoholic beverages, or prescription or non-prescription products containing alcohol, while on Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension therapy. The co-ingestion of alcohol with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may result in increased plasma levels and a potentially fatal overdose of hydrocodone [ see Drug Interactions (7.1)].

5.9 Risks of Use in Patients with Gastrointestinal Conditions

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is contraindicated in patients with known or suspected gastrointestinal obstruction, including paralytic ileus [ see Contraindications (4)]. The use of hydrocodone in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may obscure the diagnosis or clinical course of patients with acute abdominal conditions.

The concurrent use of anticholinergics with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may produce paralytic ileus [ ]. The concurrent use of anticholinergics with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may produce paralytic ileus [ see Drug Interactions (7.10)].

The hydrocodone in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may result in constipation or obstructive bowel disease, especially in patients with underlying intestinal motility disorders. Use with caution in patients with underlying intestinal motility disorders.The hydrocodone in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may result in constipation or obstructive bowel disease, especially in patients with underlying intestinal motility disorders. Use with caution in patients with underlying intestinal motility disorders.

The hydrocodone in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may cause spasm of the sphincter of Oddi, resulting in an increase in biliary tract pressure. Opioids may cause increases in serum amylase [ ]. Monitor patients with biliary tract disease, including acute pancreatitis for worsening symptoms. The hydrocodone in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may cause spasm of the sphincter of Oddi, resulting in an increase in biliary tract pressure. Opioids may cause increases in serum amylase [ see Warnings and Precautions (5.15)]. Monitor patients with biliary tract disease, including acute pancreatitis for worsening symptoms.

5.10 Risks of Use in Patients with Head Injury, Impaired Consciousness, Increased Intracranial Pressure, or Brain Tumors

Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients with head injury, intracranial lesions, or a pre-existing increase in intracranial pressure. In patients who may be susceptible to the intracranial effects of CO 2 retention (e.g., those with evidence of increased intracranial pressure or brain tumors), Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may reduce respiratory drive, and the resultant CO 2 retention can further increase intracranial pressure. Furthermore, opioids produce adverse reactions that may obscure the clinical course of patients with head injuries.

5.11 Increased Risk of Seizures in Patients with Seizure Disorders

The hydrocodone and chlorpheniramine in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may increase the frequency of seizures in patients with seizure disorders and may increase the risk of seizures occurring in other clinical settings associated with seizures. Monitor patients with a history of seizure disorders for worsened seizure control during Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension therapy.

5.12 Severe Hypotension

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may cause severe hypotension including orthostatic hypotension and syncope in ambulatory patients. There is increased risk in patients whose ability to maintain blood pressure has already been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (e.g., phenothiazines or general anesthetics) [ see Drug Interactions (7.5)] . Monitor these patients for signs of hypotension after initiating Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension.

In patients with circulatory shock, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension  may cause vasodilation that can further reduce cardiac output and blood pressure. Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients with circulatory shock.In patients with circulatory shock, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension  may cause vasodilation that can further reduce cardiac output and blood pressure. Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients with circulatory shock.

5.13 Neonatal Opioid Withdrawal Syndrome

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is not recommended for use in pregnant women. Prolonged use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension during pregnancy can result in withdrawal in the neonate. Neonatal opioid withdrawal syndrome, unlike opioid withdrawal syndrome in adults, may be life-threatening if not recognized and treated, and requires management according to protocols developed by neonatology experts. Observe newborns for signs of neonatal opioid withdrawal syndrome and manage accordingly. Advise pregnant women using opioids for a prolonged period of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available. [ see Use in Specific Populations (8.1), Patient Counseling Information (17)]

5.14 Adrenal Insufficiency

Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Presentation of adrenal insufficiency may include non-specific symptoms and signs including nausea, vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure. If adrenal insufficiency is suspected, confirm the diagnosis with diagnostic testing as soon as possible. If adrenal insufficiency is diagnosed, treat with physiologic replacement doses of corticosteroids. Wean the patient off of the opioid to allow adrenal function to recover and continue corticosteroid treatment until adrenal function recovers. Other opioids may be tried as some cases reported use of a different opioid without recurrence of adrenal insufficiency. The information available does not identify any particular opioids as being more likely to be associated with adrenal insufficiency.

5.15 Drug/Laboratory Test Interactions

Because opioid agonists may increase biliary tract pressure, with resultant increase in plasma amylase or lipase levels, determination of these enzyme levels may be unreliable for 24 hours after administration of a dose of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension.

7.1 Alcohol

Concomitant use of alcohol with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension can result in an increase of hydrocodone plasma levels and potentially fatal overdose of hydrocodone. Instruct patients not to consume alcoholic beverages or use prescription or nonprescription products containing alcohol while on Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension therapy [ see Warnings and Precautions (5.8), Clinical Pharmacology (12.3)]

7.2 Inhibitors of CYP3A4 and CYP2D6

The concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension and CYP3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), or protease inhibitors (e.g., ritonavir), can increase the plasma concentration of hydrocodone, resulting in increased or prolonged opioid effects. These effects could be more pronounced with concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension and CYP2D6 and CYP3A4 inhibitors, particularly when an inhibitor is added after a stable dose of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is achieved [ see Warnings and Precautions (5.7)]. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the hydrocodone plasma concentration will decrease [ see Clinical Pharmacology (12.3)], resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to hydrocodone.

Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension while taking a CYP3A4 or CYP2D6 inhibitor. If concomitant use is necessary, monitor patients for respiratory depression and sedation at frequent intervals.

7.3 CYP3A4 Inducers

The concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension and CYP3A4 inducers such as rifampin, carbamazepine, or phenytoin, can decrease the plasma concentration of hydrocodone [ see Clinical Pharmacology (12.3)], resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to hydrocodone [ see Warnings and Precautions (5.7)]. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the hydrocodone plasma concentration will increase [ see Clinical Pharmacology (12.3)], which could increase or prolong both the therapeutic effects and adverse reactions and may cause serious respiratory depression.

Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients who are taking CYP3A4 inducers. If concomitant use of a CYP3A4 inducer is necessary, follow the patient for reduced efficacy.

7.4 Phenytoin

Adverse event reports in the literature suggest a possible drug interaction involving increased serum phenytoin levels and phenytoin toxicity when chlorpheniramine and phenytoin are co-administered. The exact mechanism for this interaction is not known, however it is believed that chlorpheniramine may inhibit the hepatic metabolism of phenytoin. Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension  in patients who are taking phenytoin.

7.5 Benzodiazepines, and Other CNS Depressants

Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients who are taking benzodiazepines or other CNS depressants [ see Warnings and Precautions (5.8)] and instruct patients to avoid consumption of alcohol while on Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension [ see Drug Interactions (7.1), Patient Counseling Information (17)].

7.6 Serotonergic Drugs

The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation. Discontinue Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension if serotonin syndrome is suspected.

7.7 Monoamine Oxidase Inhibitors (MAOIs)

Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients who are taking monoamine oxidase inhibitors (MAOIs) or have taken MAOIs within 14 days. The use of MAOIs or tricyclic antidepressants with hydrocodone, one of the active ingredients in Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, may increase the effect of either the antidepressant or hydrocodone. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (e.g., respiratory depression, coma) .

7.8 Muscle Relaxants

Hydrocodone may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients taking muscle relaxants. If concomitant use is necessary, monitor patients for signs of respiratory depression that may be greater than otherwise expected.

7.9 Diuretics

Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed.

7.10 Anticholinergic Drugs

The concomitant use of anticholinergic drugs with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus [ see Warnings and Precautions (5.9)]. Monitor patients for signs of urinary retention or reduced gastric motility when Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is used concomitantly with anticholinergic drugs.

Additive adverse effects resulting from cholinergic blockade (e.g., xerostomia, blurred vision, or constipation) may occur when anticholinergic drugs are administered with chlorpheniramine.

8.1 Pregnancy

8.2 Lactation

Risk Summary

Because of the potential for serious adverse reactions, including excess sedation, respiratory depression, and death in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension.

There are no data on the presence of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in human milk, the effects of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension on the breastfed infant, or the effects of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension on milk production; however, data are available with hydrocodone and chlorpheniramine.

Hydrocodone

 Hydrocodone is present in breast milk. Published cases report variable concentrations of hydrocodone and hydromorphone (an active metabolite) in breast milk with administration of immediate-release hydrocodone to nursing mothers in the early post-partum period with relative infant doses of hydrocodone ranging between 1.4 and 3.7%. There are case reports of excessive sedation and respiratory depression in breastfed infants exposed to hydrocodone. No information is available on the effects of hydrocodone on milk production.

Chlorpheniramine

Chlorpheniramine is present in human milk. Chlorpheniramine has not been reported to cause effects on the breastfed infant. The published literature suggests that chlorpheniramine may decrease milk production based on its anticholinergic effects. ( see Clinical Considerations)

Clinical Considerations

Infants exposed to Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension through breast milk should be monitored for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid is stopped, or when breastfeeding is stopped.

8.3 Females and Males of Reproductive Potential

Infertility

Chronic use of opioids, such as hydrocodone, a component of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, may cause reduced fertility in females and males of reproductive potential. It is not known whether these effects on fertility are reversible [ see Adverse Reactions (6), Clinical Pharmacology (12.2)] .

8.4 Pediatric Use

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is not indicated for use in patients younger than 18 years of age because the benefits of symptomatic treatment of cough associated with allergies or the common cold do not outweigh the risks for use of hydrocodone in these patients [ see Indications (1), Warnings and Precautions (5.3)].

Life-threatening respiratory depression and death have occurred in children who received hydrocodone [ see Warnings and Precautions (5.2)]. Because of the risk of life-threatening respiratory depression and death, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is contraindicated in children less than 6 years of age [ see Contraindications (4)].

8.5 Geriatric Use

Clinical studies have not been conducted with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in geriatric populations.

Use caution when considering the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension in patients 65 years of age or older. Elderly patients may have increased sensitivity to hydrocodone; greater frequency of decreased hepatic, renal, or cardiac function; or concomitant disease or other drug therapy [ see Warnings and Precautions (5.4)].

Respiratory depression is the chief risk for elderly patients treated with opioids, including Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension. Respiratory depression has occurred after large initial doses of opioids were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration [ see Warnings and Precautions ( 5.4, 5.8) ].

Hydrocodone is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, monitor these patients closely for respiratory depression, sedation, and hypotension.

8.6 Renal Impairment

The pharmacokinetics of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension has not been characterized in patients with renal impairment. Patients with renal impairment may have higher plasma concentrations than those with normal function [ see Clinical Pharmacology (12.3)]. Chlorpheniramine is cleared substantially by the kidney. As such, impaired renal function could potentially lead to the risk of decreased clearance and thereby increased retention or systemic levels of chlorpheniramine. Therefore, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension should be used with caution in patients with severe impairment of renal function, and patients should be monitored closely for signs of hydrocodone toxicity (respiratory depression, sedation, and hypotension) and chlorpheniramine toxicity.

8.7 Hepatic Impairment

The pharmacokinetics of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension has not been characterized in patients with hepatic impairment. Patients with severe hepatic impairment may have higher plasma concentrations than those with normal hepatic function [ see Clinical Pharmacology (12.3)]. Chlorpheniramine is extensively metabolized by liver before elimination from the body. As such, impaired hepatic function could potentially lead to the risk of decreased metabolism and thereby increased systemic levels of chlorpheniramine. Therefore, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension should be used with caution in patients with severe impairment of hepatic function, and patients should be monitored closely for signs of hydrocodone toxicity (respiratory depression, sedation, and hypotension) and chlorpheniramine toxicity.

9.1 Controlled Substance

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension contains hydrocodone bitartrate, a Schedule II controlled substance.

9.2 Abuse

Hydrocodone

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension contains hydrocodone, a substance with a high potential for abuse similar to other opioids including morphine and codeine. Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension can be abused and is subject to misuse, addiction, and criminal diversion [ see Warnings and Precautions (5.1)] .

All patients treated with opioids require careful monitoring for signs of abuse and addiction, since use of opioid analgesic and antitussive products carries the risk of addiction even under appropriate medical use.

Prescription drug abuse is the intentional non-therapeutic use of a prescription drug, even once, for its rewarding psychological or physiological effects.

Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that develop after repeated substance use and includes: a strong desire to take the drug, difficulties in controlling its use, persisting in its use despite harmful consequences, a higher priority given to drug use than to other activities and obligations, increased tolerance, and sometimes a physical withdrawal.

“Drug-seeking” behavior is very common in persons with substance use disorders. Drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated “loss” of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating health care provider(s). “Doctor shopping” (visiting multiple prescribers to obtain additional prescriptions) is common among drug abusers and people suffering from untreated addiction. Preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with poor pain control.

Abuse and addiction are separate and distinct from physical dependence and tolerance. Health care providers should be aware that addiction may not be accompanied by concurrent tolerance and symptoms of physical dependence in all addicts. In addition, abuse of opioids can occur in the absence of true addiction.

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension, like other opioids, can be diverted for non-medical use into illicit channels of distribution. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised.

Proper assessment of the patient, proper prescribing practices, periodic re-evaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs.

Risks Specific to Abuse of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension

Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is for oral use only. Abuse of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension poses a risk of overdose and death. The risk is increased with concurrent use of Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension with alcohol and other central nervous system depressants [ see Warnings and Precautions (5.8), Drug Interactions ( 7.1, 7.5) ].

Parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and HIV.

9.3 Dependence

Psychological dependence, physical dependence, and tolerance may develop upon repeated administration of opioids; therefore, Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension should be prescribed and administered for the shortest duration that is consistent with individual patient treatment goals and patients should be reevaluated prior to refills [ see Dosage and Administration (2.3), Warnings and Precautions (5.1)].

Physical dependence, the condition in which continued administration of the drug is required to prevent the appearance of a withdrawal syndrome, assumes clinically significant proportions only after several weeks of continued oral opioid use, although some mild degree of physical dependence may develop after a few days of opioid therapy.

If Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension is abruptly discontinued in a physically-dependent patient, a withdrawal syndrome may occur. Withdrawal also may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone, nalmefene), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). Some or all of the following can characterize this syndrome: restlessness, lacrimation, rhinorrhea, yawning, perspiration, chills, myalgia, and mydriasis. Other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate.

Infants born to mothers physically dependent on opioids will also be physically dependent and may exhibit respiratory difficulties and withdrawal signs [ see Use in Specific Populations (8.1)].

Hydrocodone Polistirex

The chemical name for hydrocodone, a centrally-acting narcotic antitussive, is 4,5α-epoxy-3-methoxy-17- methylmorphinan-6-one. Hydrocodone polistirex is a complex of sulfonated styrene-divinylbenzene copolymer. The molecular weight for hydrocodone and the polistirex resin is 298.364 g/mol and n x 315 g/mol- 1, respectively. The molecular formula for hydrocodone and the polistirex resin is C 18H 21NO 3 and (C 18SO 3H 19)n, respectively. It has the following structural formula:

Chlorpheniramine Polistirex

The chemical name for chlorpheniramine, an antihistamine, is 2-[p-chloro-α-[2-(dimethylamino)ethyl]- benzyl]pyridine. Chlorpheniramine polistirex is a complex of sulfonated styrene-divinylbenzene copolymer. The molecular weight for chlorpheniramine and the polistirex resin is 274.79 g/mol and n x 315 g/mol-1, respectively. The molecular formula for chlorpheniramine and the polistirex resin is C 16N 2H 19Cl and (C 18SO 3H 19)n, respectively. It has the following structural formula:

12.1 Mechanism of Action

12.2 Pharmacodynamics

Hydrocodone

Effects on the Central Nervous System

Hydrocodone produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and to electrical stimulation.

Hydrocodone causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings).  Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations.

Effects on the Gastrointestinal Tract and Other Smooth Muscle

Hydrocodone causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase.

Effects on the Cardiovascular System

Hydrocodone produces peripheral vasodilation which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes and sweating and/or orthostatic hypotension.

Effects on the Endocrine System

Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormone (LH) in humans [ see Adverse Reactions (6)]. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon.

Chronic use of opioids may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [ see Adverse Reactions (6)].

Effects on the Immune System

Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive.

Concentration–Adverse Reaction Relationships

There is a relationship between increasing hydrocodone plasma concentration and increasing frequency of dose- related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid- tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions.

12.3 Pharmacokinetics

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenicity, mutagenicity, and fertility studies have not been conducted with Hydrocodone Polistirex and Chlorpheniramine Polistirex Extended-Release Oral Suspension; however, published information is available for the individual active ingredients or related active ingredients.

Hydrocodone

Carcinogenicity studies were conducted with codeine, an opiate related to hydrocodone. Two-year studies in F344/N rats and B6C3F1 mice were conducted to assess the carcinogenic potential of codeine. No evidence of tumorigenicity was observed in male and female rats at codeine dietary doses up to 70 and 80 mg/kg/day (approximately equivalent to 55 and 65 times the MRHD of hydrocodone on a mg/m 2 basis, respectively). No evidence of tumorigenicity was observed in male and female mice at codeine dietary doses up to 400 mg/kg/day (approximately equivalent to 160 times the MRHD of hydrocodone on a mg/m 2 basis).

Mutagenicity studies with hydrocodone have not been conducted.

Fertility studies with hydrocodone have not been conducted.

Chlorpheniramine

Carcinogenicity studies were conducted with chlorpheniramine maleate. Two-year studies in F344/N rats and B6C3F1 mice were conducted to assess the carcinogenic potential of chlorpheniramine. No evidence of tumorigenicity was observed in male and female rats at chlorpheniramine oral doses up to 30 and 60 mg/kg/day for 5 days/week (approximately equivalent to 25 and 50 times the MRHD on a mg/m 2 basis, respectively). No evidence of tumorigenicity was observed in male and female mice at chlorpheniramine oral doses up to 50 and 200 mg/kg/day for 5 days/week (approximately equivalent to 20 and 85 times the MRHD on a mg/m 2 basis, respectively).

Chlorpheniramine maleate was not mutagenic in the in vitro bacterial reverse mutation assay or the in vitro mouse lymphoma forward mutation assay. Chlorpheniramine maleate was clastogenic in the in vitro Chinese hamster ovary (CHO) cell chromosomal aberration assay.

Chlorpheniramine maleate had no effects on fertility in rats and rabbits at oral doses approximately 35 and 45 times the MRHD on a mg/m 2 basis, respectively.

Store at 20 to 25°C (68 to 77°F); excursions permitted to 15 to 30°C (59 to 86°F). [see USP Controlled Room Temperature.]

Dispense in a tight, light-resistant container, as defined in the USP, with a child resistant closure.

Ensure that patients have an oral dosing dispenser that measures the appropriate volume in milliliters. Counsel patients on how to utilize the oral dosing dispenser and correctly measure the oral suspension as prescribed.