Verapamil Hydrochloride 120 mg Tablet, Film Coated, 100-count — NDC 0591-0345-01 (Billing 00591-0345-01)

WARNINGS Heart failure: Verapamil has a negative inotropic effect, which in most patients is compensated by its afterload reduction (decreased systemic vascular resistance) properties without a net impairment of ventricular performance. In clinical experience with 4,954 patients, 87 (1.8%) developed congestive heart failure or pulmonary edema. Verapamil should be avoided in patients with severe left ventricular dysfunction (e.g., ejection fraction less than 30%) or moderate to severe symptoms of cardiac failure and in patients with any degree of ventricular dysfunction if they are receiving a beta-adrenergic blocker (see PRECAUTIONS, Drug interactions ).

Patients with milder ventricular dysfunction should, if possible, be controlled with optimum doses of digitalis and/or diuretics before verapamil treatment. ( Note interactions with digoxin under PRECAUTIONS .) Hypotension: Occasionally, the pharmacologic action of verapamil may produce a decrease in blood pressure below normal levels, which may result in dizziness or symptomatic hypotension. The incidence of hypotension observed in 4,954 patients enrolled in clinical trials was 2.5%.

In hypertensive patients, decreases in blood pressure below normal are unusual. Tilt-table testing (60 degrees) was not able to induce orthostatic hypotension. Elevated liver enzymes: Elevations of transaminases with and without concomitant elevations in alkaline phosphatase and bilirubin have been reported.

Such elevations have sometimes been transient and may disappear even with continued verapamil treatment. Several cases of hepatocellular injury related to verapamil have been proven by rechallenge; half of these had clinical symptoms (malaise, fever, and/or right upper quadrant pain), in addition to elevation of SGOT, SGPT, and alkaline phosphatase. Periodic monitoring of liver function in patients receiving verapamil is therefore prudent.

Accessory bypass tract (Wolff-Parkinson-White or Lown-Ganong-Levine): Some patients with paroxysmal and/or chronic atrial fibrillation or atrial flutter and a coexisting accessory AV pathway have developed increased antegrade conduction across the accessory pathway bypassing the AV node, producing a very rapid ventricular response or ventricular fibrillation after receiving intravenous verapamil (or digitalis). Although a risk of this occurring with oral verapamil has not been established, such patients receiving oral verapamil may be at risk and its use in these patients is contraindicated (see CONTRAINDICATIONS ).

Treatment is usually DC-cardioversion. Cardioversion has been used safely and effectively after oral verapamil hydrochloride. Atrioventricular block: The effect of verapamil on AV conduction and the SA node may cause asymptomatic first-degree AV block and transient bradycardia, sometimes accompanied by nodal escape rhythms.

PR-interval prolongation is correlated with verapamil plasma concentrations especially during the early titration phase of therapy. Higher degrees of AV block, however, were infrequently (0.8%) observed. Marked first-degree block or progressive development to second- or third-degree AV block requires a reduction in dosage or, in rare instances, discontinuation of verapamil hydrochloride and institution of appropriate therapy, depending on the clinical situation.

Patients with hypertrophic cardiomyopathy (IHSS): In 120 patients with hypertrophic cardiomyopathy (most of them refractory or intolerant to propranolol) who received therapy with verapamil at doses up to 720 mg/day, a variety of serious adverse effects were seen. Three patients died in pulmonary edema; all had severe left ventricular outflow obstruction and a past history of left ventricular dysfunction. Eight other patients had pulmonary edema and/or severe hypotension; abnormally high (greater than 20 mm Hg) pulmonary wedge pressure and a marked left ventricular outflow obstruction were present in most of these patients.

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ADVERSE REACTIONS Serious adverse reactions are uncommon when verapamil hydrochloride therapy is initiated with upward dose titration within the recommended single and total daily dose. See WARNINGS for discussion of heart failure, hypotension, elevated liver enzymes, AV block, and rapid ventricular response. Reversible (upon discontinuation of verapamil) non-obstructive, paralytic ileus has been infrequently reported in association with the use of verapamil.

The following reactions to orally administered verapamil occurred at rates greater than 1% or occurred at lower rates but appeared clearly drug-related in clinical trials in 4,954 patients: Constipation 7.3% Dyspnea 1.4% Dizziness 3.3% Bradycardia (HR <50/min) 1.4% Nausea 2.7% AV block total (1°, 2°, 3°) 1.2% Hypotension 2.5% 2° and 3° 0.8% Headache 2.2% Rash 1.2% Edema 1.9% Flushing 0.6% CHF, Pulmonary edema 1.8% Fatigue 1.7% Elevated liver enzymes (see WARNINGS ) In clinical trials related to the control of ventricular response in digitalized patients who had atrial fibrillation or flutter, ventricular rates below 50 at rest occurred in 15% of patients and asymptomatic hypotension occurred in 5% of patients.

The following reactions, reported in 1% or less of patients, occurred under conditions (open trials, marketing experience) where a causal relationship is uncertain; they are listed to alert the physician to a possible relationship: Cardiovascular: angina pectoris, atrioventricular dissociation, chest pain, claudication, myocardial infarction, palpitations, purpura (vasculitis), syncope. Digestive system: diarrhea, dry mouth, gastrointestinal distress, gingival hyperplasia. Hemic and lymphatic: ecchymosis or bruising.

Nervous system: cerebrovascular accident, confusion, equilibrium disorders, insomnia, muscle cramps, paresthesia, psychotic symptoms, shakiness, somnolence, extrapyramidal symptoms. Skin: arthralgia and rash, exanthema, hair loss, hyperkeratosis, macules, sweating, urticaria, Stevens-Johnson syndrome, erythema multiforme. Special senses: blurred vision, tinnitus.

Urogenital: gynecomastia, galactorrhea/hyperprolactinemia, increased urination, spotty menstruation, impotence. Treatment of acute cardiovascular adverse reactions: The frequency of cardiovascular adverse reactions that require therapy is rare; hence, experience with their treatment is limited. Whenever severe hypotension or complete AV block occurs following oral administration of verapamil, the appropriate emergency measures should be applied immediately; e.g., intravenously administered norepinephrine bitartrate, atropine sulfate, isoproterenol hydrochloride (all in the usual doses), or calcium gluconate (10% solution).

In patients with hypertrophic cardiomyopathy (IHSS), alpha-adrenergic agents (phenylephrine hydrochloride, metaraminol bitartrate, or methoxamine hydrochloride) should be used to maintain blood pressure, and isoproterenol and norepinephrine should be avoided. If further support is necessary, dopamine hydrochloride or dobutamine hydrochloride may be administered. Actual treatment and dosage should depend on the severity of the clinical situation and the judgment and experience of the treating physician.

To report SUSPECTED ADVERSE REACTIONS, contact Teva at 1-888-838-2872 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Drug interactions Cytochrome inducers/inhibitors: In vitro metabolic studies indicate that verapamil is metabolized by cytochrome P450 CYP3A4, CYP1A2, CYP2C8, CYP2C9, and CYP2C18. Clinically significant interactions have been reported with inhibitors of CYP3A4 (e.g., erythromycin, ritonavir) causing elevation of plasma levels of verapamil while inducers of CYP3A4 (e.g., rifampin) have caused a lowering of plasma levels of verapamil. HMG-CoA reductase inhibitors: The use of HMG-CoA reductase inhibitors that are CYP3A4 substrates in combination with verapamil has been associated with reports of myopathy/rhabdomyolysis.

Coadministration of multiple doses of 10 mg of verapamil with 80 mg simvastatin resulted in exposure to simvastatin 2.5-fold that following simvastatin alone. Limit the dose of simvastatin in patients on verapamil to 10 mg daily. Limit the daily dose of lovastatin to 40 mg.

Lower starting and maintenance doses of other CYP3A4 substrates (e.g., atorvastatin) may be required as verapamil may increase the plasma concentration of these drugs. Aspirin: In a few reported cases, coadministration of verapamil with aspirin has led to increased bleeding times greater than observed with aspirin alone. Grapefruit juice: Grapefruit juice may increase plasma levels of verapamil.

Alcohol: Verapamil may increase blood alcohol concentrations and prolong its effects. Beta-blockers: Controlled studies in small numbers of patients suggest that the concomitant use of verapamil hydrochloride and oral beta-adrenergic blocking agents may be beneficial in certain patients with chronic stable angina or hypertension, but available information is not sufficient to predict with confidence the effects of concurrent treatment in patients with left ventricular dysfunction or cardiac conduction abnormalities.

Concomitant therapy with beta-adrenergic blockers and verapamil may result in additive negative effects on heart rate, atrioventricular conduction and/or cardiac contractility. In one study involving 15 patients treated with high doses of propranolol (median dose: 480 mg/day; range: 160 to 1,280 mg/day) for severe angina, with preserved left ventricular function (ejection fraction greater than 35%), the hemodynamic effects of additional therapy with verapamil hydrochloride were assessed using invasive methods. The addition of verapamil to high-dose beta-blockers induced modest negative inotropic and chronotropic effects that were not severe enough to limit short-term (48 hours) combination therapy in this study.

These modest cardiodepressant effects persisted for greater than 6 but less than 30 hours after abrupt withdrawal of beta-blockers and were closely related to plasma levels of propranolol. The primary verapamil/beta-blocker interaction in this study appeared to be hemodynamic rather than electrophysiologic. In other studies, verapamil did not generally induce significant negative inotropic, chronotropic, or dromotropic effects in patients with preserved left ventricular function receiving low or moderate doses of propranolol (less than or equal to 320 mg/day); in some patients, however, combined therapy did produce such effects.

Therefore, if combined therapy is used, close surveillance of clinical status should be carried out. Combined therapy should usually be avoided in patients with atrioventricular conduction abnormalities and those with depressed left ventricular function. Asymptomatic bradycardia (36 beats/min) with a wandering atrial pacemaker has been observed in a patient receiving concomitant timolol (a beta-adrenergic blocker) eyedrops and oral verapamil.

A decrease in metoprolol and propranolol clearance has been observed when either drug is administered concomitantly with verapamil. A variable effect has been seen when verapamil and atenolol were given together. Digitalis: Clinical use of verapamil in digitalized patients has shown the combination to be well tolerated if digoxin doses are properly adjusted.

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PRECAUTIONS General Use in patients with impaired hepatic function: Since verapamil is highly metabolized by the liver, it should be administered cautiously to patients with impaired hepatic function. Severe liver dysfunction prolongs the elimination half-life of verapamil to about 14 to 16 hours; hence, approximately 30% of the dose given to patients with normal liver function should be administered to these patients. Careful monitoring for abnormal prolongation of the PR interval or other signs of excessive pharmacologic effects (see OVERDOSAGE ) should be carried out.

Use in patients with attenuated (decreased) neuromuscular transmission: It has been reported that verapamil decreases neuromuscular transmission in patients with Duchenne’s muscular dystrophy, prolongs recovery from the neuromuscular blocking agent vecuronium, and causes a worsening of myasthenia gravis. It may be necessary to decrease the dosage of verapamil when it is administered to patients with attenuated neuromuscular transmission. Use in patients with impaired renal function: About 70% of an administered dose of verapamil is excreted as metabolites in the urine.

Verapamil is not removed by hemodialysis. Until further data are available, verapamil should be administered cautiously to patients with impaired renal function. These patients should be carefully monitored for abnormal prolongation of the PR interval or other signs of overdosage (see OVERDOSAGE ).

Drug interactions Cytochrome inducers/inhibitors: In vitro metabolic studies indicate that verapamil is metabolized by cytochrome P450 CYP3A4, CYP1A2, CYP2C8, CYP2C9, and CYP2C18. Clinically significant interactions have been reported with inhibitors of CYP3A4 (e.g., erythromycin, ritonavir) causing elevation of plasma levels of verapamil while inducers of CYP3A4 (e.g., rifampin) have caused a lowering of plasma levels of verapamil. HMG-CoA reductase inhibitors: The use of HMG-CoA reductase inhibitors that are CYP3A4 substrates in combination with verapamil has been associated with reports of myopathy/rhabdomyolysis.

Coadministration of multiple doses of 10 mg of verapamil with 80 mg simvastatin resulted in exposure to simvastatin 2.5-fold that following simvastatin alone. Limit the dose of simvastatin in patients on verapamil to 10 mg daily. Limit the daily dose of lovastatin to 40 mg.

Lower starting and maintenance doses of other CYP3A4 substrates (e.g., atorvastatin) may be required as verapamil may increase the plasma concentration of these drugs. Aspirin: In a few reported cases, coadministration of verapamil with aspirin has led to increased bleeding times greater than observed with aspirin alone. Grapefruit juice: Grapefruit juice may increase plasma levels of verapamil.

Alcohol: Verapamil may increase blood alcohol concentrations and prolong its effects. Beta-blockers: Controlled studies in small numbers of patients suggest that the concomitant use of verapamil hydrochloride and oral beta-adrenergic blocking agents may be beneficial in certain patients with chronic stable angina or hypertension, but available information is not sufficient to predict with confidence the effects of concurrent treatment in patients with left ventricular dysfunction or cardiac conduction abnormalities.

Concomitant therapy with beta-adrenergic blockers and verapamil may result in additive negative effects on heart rate, atrioventricular conduction and/or cardiac contractility. In one study involving 15 patients treated with high doses of propranolol (median dose: 480 mg/day; range: 160 to 1,280 mg/day) for severe angina, with preserved left ventricular function (ejection fraction greater than 35%), the hemodynamic effects of additional therapy with verapamil hydrochloride were assessed using invasive methods. The addition of verapamil to high-dose beta-blockers induced modest negative inotropic and chronotropic effects that were not severe enough to limit short-term (48 hours) combination therapy in this study.

The… [Excerpted — this section continues on DailyMed.]