Generic
Verapamil Hydrochloride
13 brands available in the market
At a glance
Verapamil Hydrochloride is used to treat angina, high blood pressure and some types of irregular heartbeats (arrhythmia). It works by relaxing blood vessels to lower blood pressure.
Description
Verapamil is an L-type calcium channel blocker with antiarrhythmic, antianginal, and antihypertensive activity. It inhibits the inward movement of calcium into cardiomyocytes, smooth muscle cells and His-Purkingi system.
Indications
- Hypertension (high blood pressure)
- Angina (heart-related chest pain)
- Arrhythmia
- Supraventricular arrhythmias
- Chronic atrial fibrillation
- Paroxysmal supraventricular tachycardia
- Tardive dyskinesia
Therapeutic class
Calcium-channel blockers
Pharmacological class
Calcium-channel blocker
Pharmacology
Verapamil inhibits entry of calcium ions into arterial smooth muscle cells as well as the myocytes and conducting tissue. These actions lead to reversal and prevention of coronary artery spasm, reduction in afterload through peripheral vasodilatation and reduction in ventricular rate in patients with chronic atrial flutter or fibrillation.
Mechanism of action
Blocks calcium channels, dilating blood vessels, lowering blood pressure and reducing cardiac workload.
Dosage
Adult Dose (Oral):
- Hypertension: Immediate release 80 mg every 8 hours initially; maintenance 80-320 mg every 12 hours; Extended release 180 mg/day initially; may increase to 240 mg/day, then by 120 mg/day at weekly intervals; max 480 mg/day
- Angina: Immediate release 80 mg every 8 hours; usual range 80-120 mg every 8 hours; max 480 mg/day
- Chronic atrial fibrillation & paroxysmal supraventricular tachycardia: Immediate release 240-480 mg/day divided every 6-8 hours
- Hepatic impairment: In cirrhosis, reduce dose by 20-50%
Adult Dose (IV):
- 2.5-5 mg IV over 2 minutes; 5-10 mg dose may be repeated after 15-30 minutes
Administration
- Take with food
- Swallow whole; do not chew, crush or break
- Take at the same time each day
Missed dose
If you miss a dose, take it as soon as you remember; if almost time for next dose, skip it; do not double the dose.
Side effects
Common Side Effects:
- Headache
- Constipation
- Infection
- Dizziness
- Sinus infection
- Flu-like symptoms
- Peripheral edema
- Hypotension
- Bradycardia
Precautions & warnings
- May decrease alertness; do not drive
- May cause dizziness or sleepiness; do not drive
- Orthostatic hypotension may occur; rise slowly if you have been sitting or lying down
- Avoid alcohol; may worsen side effects
- Contraindicated in severe left ventricular dysfunction, hypotension, sick sinus syndrome, 2nd or 3rd degree AV block
Contraindications
- Cardiogenic shock
- Hypotension (systolic pressure <90 mmHg)
- Marked bradycardia
- Uncompensated heart failure
- 2nd or 3rd degree AV block (unless pacemaker fitted)
- Sick-sinus syndrome
- Severe ventricular dysfunction
- Atrial flutter or atrial fibrillation and accessory bypass tract (WPW, LGL syndromes)
Drug interactions
- Beta-blockers and flecainide: increased cardiac depressant effects
- Digoxin: increased risk of additive bradycardia, conduction disturbances and digoxin toxicity
- Remifentanil and sufentanil: increased risk of bradycardia and hypotension
- Everolimus: increased levels of both
- Doxorubicin, buspirone, carbamazepine, ciclosporin, epirubicin, eplerenone, quinidine, statins, sirolimus, tacrolimus: may increase levels
- Phenobarbital, sulfinpyrazone, rifampicin, rifabutin, rifapentine: decreased verapamil concentrations
- Protease inhibitors and cimetidine: increased verapamil concentrations
- Amiodarone: increased cardiac depressant effects (potentially fatal)
- Dofetilide, ranolazine, sertindole: increased risk of QT prolongation (potentially fatal)
- Ivabradine: additive bradycardia (potentially fatal)
- Clonidine: increased risk of heart block (potentially fatal)
- Dantrolene: increased risk of acute hyperkalaemia and CV collapse (potentially fatal)
Food interactions
It is unsafe to consume alcohol with Verapamil Hydrochloride.
Use in pregnancy
Use in Pregnancy: May be unsafe; animal studies show harmful effects; consult your doctor.
Pregnancy Category: C — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Safe; human studies suggest the drug does not pass into breastmilk in significant amount and is not harmful to the baby.
Pediatric use
Pediatric dosage regimen established (SVT: 1-15 years: 0.1-0.3 mg/kg IV; 4-8 mg/kg/day PO)
Geriatric use
Caution required in elderly; dose adjustment may be needed
Renal / hepatic impairment
Renal Impairment: Use with caution; monitor ECG; if CrCl <10 mL/min, reduce dose by 25-50%
Hepatic Impairment: In cirrhosis, reduce dose by 20-50%
Overdose effects
Symptoms: Hypotension, bradycardia, heart block.
Treatment: Beta-adrenergic stimulation or parenteral administration of calcium solution; verapamil cannot be removed by hemodialysis.
Storage conditions
Do not store above 30°C. Keep away from light and out of the reach of children.