Verapamil Hydrochloride
Generic Details
Generic Name
Verapamil Hydrochloride
Other Names
- Verapamil HCl
Drug Class
- Calcium Channel Blocker
Chemical Formula
C27H38ClN2O4
Molecular Weight
491.05 g/mol
Mechanism of Action
- Inhibits calcium ion influx across cell membranes
Indications
- Hypertension
- Angina
- Arrhythmias
- Migraine prophylaxis
Common Dosage Forms
- Tablet
- Extended-release tablet
- Capsule
Typical Dosage
- 80-120 mg orally every 8 hours
Pediatric Dosage
- Safety and effectiveness not established in children
Geriatric Dosage
- Consider lower initial doses due to increased sensitivity
Side Effects
- Constipation
- Dizziness
- Bradycardia
- Edema
- Hypotension
Contraindications
- Hypersensitivity to verapamil
- Sick sinus syndrome
- Second- or third-degree AV block
Pregnancy Category
- Category C - Animal reproduction studies have shown an adverse effect on the fetus
Lactation Safety
- Limited data available, caution advised
Drug Interactions
- Beta-blockers
- Digoxin
- Cyclosporine
- Statins
Overdose Symptoms
- Hypotension
- Bradycardia
- Cardiac arrhythmias
Antidote for Overdose
- Calcium chloride or calcium gluconate IV
Storage Conditions
- Store at room temperature away from light and moisture
Pharmacokinetics
- Absorption: Rapidly absorbed from the gastrointestinal tract
- Distribution: Crosses the blood-brain barrier and placenta; present in breast milk
- Metabolism: Metabolized in the liver
- Excretion: Excreted mainly in urine
Precautions
- Monitor blood pressure and heart rate regularly
- Avoid grapefruit juice due to CYP3A4 inhibition
Warnings
- Do not crush or chew extended-release formulations
Others
- May cause gingival hyperplasia