Calan (verapamil hydrochloride)
Calcium channel blocker (CCB) (nondihydropyridine)
Treatment of angina at rest including vasospastic (Prinzmetal's variant) angina and unstable (crescendo, pre-infarction) angina. Treatment of chronic stable angina (classic effort-associated angina). In association with digitalis, for the control of ventricular rate at rest and during stress in patients with chronic atrial flutter (A-flutter) and/or atrial fibrillation (A-fib). Prophylaxis of repetitive paroxysmal supraventricular tachycardia (PSVT). Treatment of essential HTN.
Initial (Monotherapy): 80mg tid (240mg/day)
Range: 360-480mg/day; no evidence that dosages >360mg/day provided added effect
Titrate: Based upward titration on therapeutic efficacy, assessed at the end of the dosing interval
Angina at rest including vasospastic (Prinzmetal's variant) angina and unstable (crescendo, pre-infarction) angina/chronic stable angina (classic effort-associated angina)
Usual: 80-120mg tid
Titrate: Base upward titration on therapeutic efficacy and safety evaluated approx 8 hrs after dosing; may increase daily (eg, patients w/ unstable angina) or at weekly intervals until optimum response is obtained
In association w/ digitalis, for the control of ventricular rate at rest and during stress in patients w/ chronic A-flutter/A-fib
Range: 240-320mg/day in divided doses tid or qid
Paroxysmal Supraventricular Tachycardia
Range: 240-480mg/day in divided doses tid or qid
Max effects for any given dosage will be apparent during the first 48 hrs of therapy
Severe Dysfunction: Give 30% of normal dose
Other Important Considerations
Patients Who May Respond to Lower Doses (eg, Elderly, People of Small Stature):
HTN: Consider beginning titration at 40mg tid
Angina: 40mg tid may be warranted
Tab: 40mg, 80mg*, 120mg* *scored
Severe left ventricular dysfunction, hypotension (systolic pressure <90mmHg) or cardiogenic shock, sick sinus syndrome or 2nd- or 3rd-degree atrioventricular (AV) block (except with functioning ventricular artificial pacemaker), A-fib/flutter and an accessory bypass tract (eg, Wolff-Parkinson-White, Lown-Ganong-Levine syndromes).
Has negative inotropic effect; avoid with severe left ventricular dysfunction (eg, ejection fraction <30%) or moderate to severe symptoms of cardiac failure. Patients with milder ventricular dysfunction should, if possible, be controlled with optimum doses of digitalis and/or diuretics before treatment. May cause congestive heart failure (CHF), pulmonary edema, hypotension, asymptomatic 1st-degree AV block, transient bradycardia, and PR interval prolongation. Marked 1st-degree AV block or progressive development to 2nd- or 3rd-degree AV block requires dose reduction, or in rare instances, discontinuation and institution of appropriate therapy. Hepatocellular injury as well as elevated transaminases with or without concomitant elevations in alkaline phosphatase and bilirubin reported; monitor LFTs periodically. Sinus bradycardia, 2nd-degree AV block, pulmonary edema, severe hypotension, and sinus arrest reported in patients with hypertrophic cardiomyopathy. Caution with renal/hepatic impairment; monitor for abnormal PR interval prolongation or other signs of overdosage. 30% of normal dose should be given to patients with severe hepatic dysfunction. May decrease neuromuscular transmission in patients with Duchenne muscular dystrophy and may cause worsening of myasthenia gravis; may be necessary to decrease dose when administered to patients with attenuated neuromuscular transmission. Caution in elderly.
CYP3A4 inhibitors (eg, erythromycin, ritonavir) and grapefruit juice may increase levels. CYP3A4 inducers (eg, rifampin) may decrease levels. May cause myopathy/rhabdomyolysis with HMG-CoA reductase inhibitors that are CYP3A4 substrates and may increase levels of such drugs; limit dose of simvastatin to 10mg/day and lovastatin to 40mg/day, and lower starting/maintenance doses of other CYP3A4 substrates (eg, atorvastatin) may be required. Increased bleeding times with aspirin. Additive negative effects on HR, AV conduction, and/or cardiac contractility with β-blockers; monitor closely and avoid with any degree of ventricular dysfunction. Combined therapy with propranolol should usually be avoided in patients with AV conduction abnormalities and those with depressed left ventricular function. May produce asymptomatic bradycardia with a wandering atrial pacemaker with timolol eye drops. Decreased metoprolol and propranolol clearance and variable effect with atenolol reported. Chronic treatment may increase digoxin levels, which may result in digitalis toxicity; reduce maintenance and digitalization doses and monitor carefully to avoid over-/under-digitalization. May reduce total body/extra renal clearance of digitoxin. Additive effects with other oral antihypertensives (eg, vasodilators, ACE inhibitors, diuretics); monitor appropriately. Coadministration with agents that attenuate α-adrenergic function (eg, prazosin) may excessively reduce BP. Avoid disopyramide within 48 hrs before or 24 hrs after administration. Coadministration with flecainide may result in additive negative inotropic effect and AV conduction prolongation. May counteract effects of quinidine on AV conduction and increase levels of quinidine; avoid concomitant use in patients with hypertrophic cardiomyopathy. Reduced or unchanged clearance with cimetidine. Increased sensitivity to effects of lithium (neurotoxicity) when used concomitantly; monitor carefully. May increase carbamazepine, theophylline, cyclosporine, and alcohol levels. Increased clearance with phenobarbital. Rifampin may reduce oral bioavailability. Titrate both verapamil and inhalation anesthetics carefully, in order to avoid excessive cardiovascular depression. May potentiate neuromuscular blockers (eg, curare-like and depolarizing); verapamil or both agents may need dose reduction. Hypotension and bradyarrhythmias reported with telithromycin. Sinus bradycardia resulting in hospitalization and pacemaker insertion reported with clonidine; monitor HR.
PREGNANCY AND LACTATION
Category C, not for use in nursing.
MECHANISM OF ACTION
Calcium channel blocker (nondihydropyridine); modulates the influx of ionic Ca2+ across the cell membrane of the arterial smooth muscle, as well as in conductile and contractile myocardial cells.
Absorption: Bioavailability (20-35%); Tmax=1-2 hrs. Distribution: Plasma protein binding (90%); crosses the placenta, found in breast milk. Metabolism: Liver (extensive); norverapamil (metabolite). Elimination: Urine (70% metabolites, 3-4% unchanged), feces (≥16%); T1/2=4.5-12 hrs (repetitive dosing).
Assess for known hypersensitivity to the drug, cardiac failure, severe left ventricular dysfunction, hypertrophic cardiomyopathy, hepatic/renal impairment, attenuated neuromuscular transmission (eg, Duchenne muscular dystrophy), any conditions where treatment is contraindicated or cautioned, pregnancy/nursing status, and possible drug interactions.
Monitor for CHF, hypotension, AV block, abnormal prolongation of the PR interval, transient bradycardia, and other adverse reactions. Monitor LFTs periodically.
Inform of the risks/benefits of therapy. Advise to seek medical attention if any adverse reactions occur.
15-25°C (59-77°F). Protect from light.
purchase calan, calan online, calan sr 180 side effects, calan sr 240, side effects of calan sr tablets, order calanoida, order calan, cheap calan, calan sr dosage forms, calan sr 120 mg, calan sr dosage, calan sr, calan sr uses, calan sr 240 side effects, calan sr side effects, calan sr 120 mg for migraines, calan sr 180, calan sr 240 mg side effects, nombre genericos de calan, calan sr tablets, buy calan, calan sr package insert, calan sr 120 mg side effects, calan sr generic