Pharmacologic Action

Nicotine, the chief alkaloid in tobacco products, binds stereo-selectively to nicotinic-cholinergic receptors at the autonomic ganglia, in the adrenal medulla, at neuromuscular junctions, and in the brain. Two types of central nervous system effects are believed to be the basis of nicotine's positively reinforcing properties. A stimulating effect is exerted mainly in the cortex via the locus ceruleus and a reward effect is exerted in the limbic system. At low doses, the stimulant effects predominate while at high doses the reward effects predominate. Intermittent intravenous administration of nicotine activates neurohormonal pathways, releasing acetylcholine, norepinephrine, dopamine, serotonin, vasopressin, beta-endorphin, growth hormone, and ACTH.

Pharmacodynamics

The cardiovascular effects of nicotine include peripheral vasoconstriction, tachycardia, and elevated blood pressure. Acute and chronic tolerance to nicotine develops from smoking tobacco or ingesting nicotine preparations. Acute tolerance (a reduction in response for a given dose) develops rapidly (less than 1 hour), but not at the same rate for different physiologic effects (skin temperature, heart rate, subjective effects). Withdrawal symptoms such as cigarette craving can be reduced in most individuals by plasma nicotine levels lower than those from smoking.

Withdrawal from nicotine in addicted individuals can be characterized by craving, nervousness, restlessness, irritability, mood lability, anxiety, drowsiness, sleep disturbances, impaired concentration, increased appetite, minor somatic complaints (headache, myalgia, constipation, fatigue), and weight gain. Nicotine toxicity is characterized by nausea, abdominal pain, vomiting, diarrhea, diaphoresis, flushing, dizziness, disturbed hearing and vision, confusion, weakness, palpitations, altered respiration and hypotension.

Both smoking and nicotine can increase circulating cortisol and catecholamines, and tolerance does not develop to the catecholamine-releasing effects of nicotine. Changes in the response to a concomitantly administered adrenergic agonist or antagonist should be watched for when nicotine intake is altered during NICOTROL NS therapy and/or smoking cessation (See PRECAUTIONS, Drug Interactions).

PHARMACOKINETICS

Each actuation of NICOTROL NS delivers a metered 50 microliter spray containing approximately 0.5 mg of nicotine. One dose is considered 1 mg of nicotine (2 sprays, one in each nostril).

Absorption

Following administration of 2 sprays of NICOTROL NS approximately 53% ± 16% (Mean ± SD) enters the systemic circulation. No significant difference in rate or extent of absorption could be seen due to the deposition of nicotine on different parts of the nasal mucosa. Plasma concentrations of nicotine obtained from 1 dose (1 mg nicotine) of NICOTROL NS rise rapidly, reaching maximum venous concentrations of 2–12 ng/mL in 4–15 minutes. The apparent absorption half-life of nicotine is approximately 3 minutes. There is wide variation among subjects in their plasma nicotine concentrations from the spray. As a result, after a 1 mg dose of spray approximately 20% of the subjects reached peak nicotine concentrations similar to those seen after smoking one cigarette (7–17 ng/mL) (See DRUG ABUSE AND DEPENDENCE Section). Figure 1 below plots the mean and 5th and 95th percentile nicotine concentrations after a 1 mg single dose of the nasal spray (n=30).

Table 1: Trough Plasma Nicotine Concentrations after 11 Hours of Dosing With 1 mg, 2 mg and 3 mg of NICOTROL NS per hour (n=16).

Dose	Mean (ng/mL) ± SD	(Range)
1 mg every 60 minutes (1 mg/hr)	6 ± 3	(1.7–12)
1 mg every 30 minutes (2 mg/hr)	14 ± 6	(1.5–24)
1 mg every 20 minutes (3 mg/hr)	18 ± 10	(1.2–35)

The data from Table 1 is derived from a three-way cross-over study of repeated applications of NICOTROL NS in sixteen smokers (8 male, 8 female) ranging in age from 18 to 48 years. There is a slight deviation from dose-concentration proportionality from one dose to three doses of NICOTROL NS per hour as shown in Figure 2.

Sixteen smokers (7 males and 9 females) ranging in age from 22 to 44 years were dosed with 1 mg of NICOTROL NS every hour for 10 hours. The pharmacokinetic parameters that were obtained are presented in Table 2.

Table 2: Nicotine Pharmacokinetic Parameters at Steady-State for 1 mg/hour of NICOTROL NS Administered Hourly for Ten Hours (Mean ± SD and Range), (n=16).

Parameter	1 mg (2 sprays)	(Range)
Cavg: average plasma nicotine concentration for the dosing interval of 10–11 hours
Cmax: maximum measured plasma concentration after last dose administration
Tmax: time of maximum plasma concentration after last dose administration
Cavg (ng/mL)	8 ± 3	(2.5–12)
Cmax (ng/mL)	9 ± 3	(3.1–14)
Tmax (minutes)	13 ± 5	(10–20)

Pregnancy, Warning

Tobacco smoke, which has been shown to be harmful to the fetus, contains nicotine, hydrogen cyanide, and carbon monoxide. Nicotine has been shown in animal studies to cause fetal harm. It is therefore presumed that NICOTROL NS can cause fetal harm when administered to a pregnant woman. The effect of nicotine delivery by NICOTROL NS has not been examined in pregnancy (See PRECAUTIONS). Therefore, pregnant smokers should be encouraged to attempt cessation using educational and behavioral interventions before using pharmacological approaches. If NICOTROL NS is used during pregnancy, or if the patient becomes pregnant while using it, the patient should be apprised of the potential hazard to the fetus.

Safety Note Concerning Children

The amounts of nicotine that are tolerated by adult smokers can produce signs and symptoms of poisoning and could prove fatal if NICOTROL NS is used or ingested by children or pets. Suspected nicotine poisoning in a child should be considered a medical emergency and treated immediately. A full bottle of NICOTROL NS contains 100 mg of nicotine, some of which will still be in the bottle when it is discarded. Therefore, patients should be cautioned to keep both used and unused containers of NICOTROL NS out of the reach of children and pets.

General

The patient should be urged to stop smoking completely when initiating NICOTROL NS therapy (See DOSAGE AND ADMINISTRATION). Patients should be informed that if they continue to smoke while using the product, they may experience adverse effects due to peak nicotine levels higher than those experienced from smoking alone. If there is a clinically significant increase in cardiovascular or other effects attributable to nicotine, the treatment should be discontinued (See WARNINGS). Physicians should anticipate that concomitant medications may need dosage adjustment (See Drug Interactions).

Sustained use (beyond 6 months) of NICOTROL NS by patients who stop smoking is not recommended and should be discouraged (See DRUG ABUSE AND DEPENDENCE).

Care should be taken not to spray the eyes while administering NICOTROL NS.

Information To Patient

A patient instruction sheet is included in the package of NICOTROL NS dispensed to the patient. Patients should be encouraged to read the instruction sheet carefully and to ask their physician and pharmacist about the proper use of the product (See DOSAGE AND ADMINISTRATION).

It should be explained to patients that they are likely to experience nasal irritation, which may become less bothersome with continued use.

Patients must be advised to keep both used and unused containers out of the reach of children and pets.

Drug Interactions

The extent of absorption and peak plasma concentration is slightly reduced in patients with the common cold/rhinitis. In addition, the time to peak concentration is prolonged. The use of a nasal vasoconstrictor such as xylometazoline in patients with rhinitis will further prolong the time to peak (See PHARMACOKINETICS). Smoking cessation, with or without nicotine replacement, may alter the pharmacokinetics of certain concomitant medications.

Carcinogenesis, Mutagenesis, Impairment Of Fertility

Nicotine itself does not appear to be a carcinogen in laboratory animals. However, nicotine and its metabolites increased the incidences of tumors in the cheek pouches of hamsters and forestomach of F344 rats, respectively, when given in combination with tumor-initiators. One study, which could not be replicated, suggested that cotinine, the primary metabolite of nicotine, may cause lymphoreticular sarcoma in the large intestine of rats.

Neither nicotine nor cotinine were mutagenic in the Ames salmonella test. Nicotine-induced repairable DNA damage in an E. coli test system. Nicotine was shown to be genotoxic in a test system using Chinese hamster ovary cells. In rats and rabbits, implantation can be delayed or inhibited by a reduction in DNA synthesis that appears to be caused by nicotine. Studies have shown a decrease in litter size in rats treated with nicotine during gestation.

PREGNANCY

The harmful effects of cigarette smoking on maternal and fetal health are clearly established. These include low birth weight, an increased risk of spontaneous abortion, and increased perinatal mortality. The specific effects of NICOTROL NS on fetal development are unknown. Therefore pregnant smokers should be encouraged to attempt cessation using educational and behavioral interventions before using pharmacological approaches.

Spontaneous abortion during nicotine replacement therapy has been reported; as with smoking, nicotine as a contributing factor cannot be excluded.

NICOTROL NS should be used during pregnancy only if the likelihood of smoking cessation justifies the potential risk of using it by the pregnant patient, who might continue to smoke.

Labor and Delivery

NICOTROL NS is not recommended for use during labor and delivery. The effect of nicotine on a mother or the fetus during labor is unknown.

Use in Nursing Mothers

Caution should be exercised when NICOTROL NS is administered to nursing mothers. The safety of NICOTROL NS therapy in nursing infants has not been examined. Nicotine passes freely into breast milk; the milk to plasma ratio averages 2.9. Nicotine is absorbed orally. An infant has the ability to clear nicotine by hepatic first-pass clearance; however, the efficiency of removal is probably lowest at birth. Nicotine concentrations in milk can be expected to be lower with NICOTROL NS when used as recommended than with cigarette smoking, as maternal plasma nicotine concentrations are generally reduced with nicotine replacement. The risk of exposure of the infant to nicotine from NICOTROL NS therapy should be weighed against the risks associated with the infant's exposure to nicotine from continued smoking by the mother (passive smoke exposure and contamination of breast milk with other components of tobacco smoke) and from NICOTROL NS alone, or in combination with continued smoking.

Pediatric Use

NICOTROL NS therapy is not recommended for use in the pediatric population because its safety and effectiveness in children and adolescents who smoke have not been evaluated.

Geriatric Use

Clinical studies of NICOTROL NS did not include sufficient numbers of subjects age 65 and over to determine whether they respond differently from younger subjects. Other reports on clinical experience have not identified differences between older and younger patients. In general, dosage selection for an elderly patient should be cautious, usually starting at the low end of the dosage range reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease.

Common Smoker's Complaints

Common complaints experienced by the smokers in the study (users of both active and placebo spray) include: chest tightness, dyspepsia, paraesthesia (tingling) in limbs, constipation, and stomatitis.

Tobacco Withdrawal Symptoms

Symptoms of tobacco withdrawal were frequent in users of both active and placebo sprays. Common withdrawal symptoms seen in over 5% of patients included: anxiety, irritability, restlessness, cravings, dizziness, impaired concentration, weight increase, emotional lability, somnolence and fatigue, increased sweating, and insomnia. Less frequently seen probable withdrawal symptoms (under 5%) included: confusion, depression, apathy, tremor, increased appetite, incoordination and increased dreaming.

Anxiety, irritability, restlessness and tobacco cravings occurred about equally in both groups, while other symptoms tended to be slightly more common on placebo spray.

Effects of the Spray

NICOTROL NS and the pepper-containing placebo were both associated with irritant side effects on the nasopharyngeal and ocular tissues. During the first 2 days of treatment, nasal irritation was reported by nearly all (94%) of the patients, the majority of whom rated it as either moderate or severe. Both the frequency and severity of nasal irritation declined with continued use of NICOTROL NS but was still experienced by most (81%) of the patients after 3 weeks of treatment, with most patients rating it as moderate or mild.

Other common side-effects for both active and placebo groups were: runny nose, throat irritation, watering eyes, sneezing, and coughing.

The following local events were reported somewhat more commonly for active than for placebo spray: nasal congestion, subjective comments related to the taste or use of the dosage form, sinus irritation, transient epistaxis, eye irritation, transient changes in sense of smell, pharyngitis, paraethesias of the nose, mouth or head, numbness of the nose, or mouth, burning of the nose or eyes, earache, facial flushing, transient changes in sense of taste, hoarseness, nasal ulcer or blister.

Effects of Nicotine

Feelings of dependence on the spray were reported by more patients on active spray than placebo. Drug-like effects such as calming were also more frequent on active spray (See DRUG ABUSE AND DEPENDENCE).

Other Adverse Effects

Adverse events which could not be classified and listed above and which were reported by >1% of patients on active spray are listed in the following table:

Adverse Events Not Attributable to Intercurrent Illness

Adverse events reported with a frequency of <1% among active spray users are listed below:

Body as a Whole: edema peripheral, pain, numbness, allergy

Gastrointestinal: dry mouth, hiccup, diarrhea

Hematologic: purpura

Neurological: aphasia, amnesia, migraine, numbness

Respiratory: bronchitis, bronchospasm, sputum increased

Skin and appendages: rash, purpura

Special Senses: vision abnormal

Adverse reactions not listed above that have been identified during post-marketing experience with the nicotine nasal spray formulation are listed below:

General disorders and administration site conditions: chest pain

Immune system disorders: anaphylactic reaction

Gastrointestinal disorders: dysphagia

Signs and Symptoms of Nicotine Toxicity

Signs and symptoms of an overdose of NICOTROL NS would be expected to be the same as those of acute nicotine poisoning including: pallor, cold sweat, nausea, salivation, vomiting, abdominal pain, diarrhea, headache, dizziness, disturbed hearing and vision, tremor, mental confusion, and weakness. Prostration, hypotension, arrhythmia, and respiratory failure may ensue with large overdoses. Lethal doses produce convulsions quickly and death follows as a result of peripheral or central respiratory paralysis or, less frequently, cardiac failure.

Overdose from Ingestion

If emesis has not occurred, it should be induced in conscious patients with a suitable emetic followed by an appropriate dose of activated charcoal. In unconscious patients with a secure airway, instill activated charcoal via a nasogastric tube. A saline cathartic or sorbitol may be added to the first dose of activated charcoal.

Management of Nicotine Poisoning

Administration of nicotine must be stopped immediately and the patient should be treated symptomatically. Other supportive measures include diazepam or barbiturates for seizures, atropine for excessive bronchial secretions or diarrhea, respiratory support for respiratory failure, and vigorous fluid support for hypotension and cardiovascular collapse.

Individualization of Dosage

The success or failure of smoking cessation is influenced by the quality, intensity and frequency of supportive care. Patients are more likely to quit smoking if they are seen frequently and participate in formal smoking cessation programs.

The goal of NICOTROL NS therapy is complete abstinence. If a patient is unable to stop smoking by the fourth week of therapy, treatment should probably be discontinued.

Patients who fail to quit on any attempt may benefit from interventions to improve their chances for success on subsequent attempts. Patients who were unsuccessful should be counseled and should then probably be given a "therapy holiday" before the next attempt. A new quit attempt should be encouraged when conditions are more favorable.

Based on the clinical trials, a reasonable approach to assisting patients in their attempt to quit smoking is to begin initial treatment, using the recommended dosage (See DOSAGE AND ADMINISTRATION). Regular use of the spray during the first week of treatment may help patients adapt to the irritant effects of the spray. Dosage can then be adjusted in those subjects with signs or symptoms of nicotine withdrawal or excess. Patients who are successfully abstinent on NICOTROL NS should be treated at the selected dosage for up to 8 weeks, following which use of the spray should be discontinued over the next 4 to 6 weeks. Some patients may not require gradual reduction of dosage and may abruptly stop treatment successfully. Treatment with NICOTROL NS for longer periods has not been shown to improve outcome, and the safety of use for periods longer than 6 months has not been established.

The symptoms of nicotine withdrawal overlap those of nicotine excess (See Pharmacodynamics and ADVERSE REACTIONS sections). Since patients using NICOTROL NS may also smoke intermittently, it is sometimes difficult to determine if patients are experiencing nicotine withdrawal or nicotine excess. Controlled clinical trials of nicotine products suggest that palpitations, nausea and sweating are more often symptoms of nicotine excess, whereas anxiety, nervousness and irritability are more often symptoms of nicotine withdrawal.

Disposal

Used bottles of NICOTROL NS should be disposed of with their child-resistant caps in place. Used bottles should be disposed of in such a way as to prevent access by children or pets. See patient information for further information on handling and disposal.

How Supplied

Nicotrol® NS (nicotine nasal spray) 10 mg/mL, is supplied as four 10 mL bottles (NDC 0009-5401-01). Each unit consists of a glass container, mounted with a metered spray pump.

A patient information leaflet is enclosed with the package.

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