Verapamil
Verapamil is a calcium channel blocker used to treat high blood pressure, certain heart rhythm disorders (such as atrial fibrillation/flutter and supraventricular tachycardia), and angina (chest pain). It works by relaxing blood vessels and reducing the heart's workload, while also slowing electrical conduction through the heart. It may also be used preventively for cluster headaches and migraine headaches in some patients.
Verapamil is a calcium channel blocker that treats high blood pressure, heart rhythm disorders, and angina by relaxing blood vessels and slowing the heart rate.
Key facts at a glance
- ATC
- C08DA01
- RxNorm
- 11170
- Generic
- Verapamil
- Class
- atc-c08
- Brands
- Isoptin, Calan, Verelan
- Availability
- rx
- Pregnancy
- C
- Lactation
- caution
- Routes
- oral
- Forms
- injection, tablet, capsule, prefilled syringe, solution
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 240mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 20mg three times daily
- Maximum
- consult physician
- Frequency
- every 8 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 120mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
9 groupspregnancy
first trimesteruse lowest effective dose
avoid use during pregnancy unless benefits outweigh risks; consider alternative therapies
regular fetal monitoring and uterine blood flow assessment
Use with caution and monitor for adverse effects.
pregnancy
third trimesteruse lowest effective dose
avoid use close to delivery due to risk of neonatal respiratory depression
fetal heart rate monitoring; assess for neonatal hypoglycemia and bradycardia
Use with caution and monitor for adverse effects.
lactation
breastfeedingno adjustment needed
compatible with breastfeeding according to AAP; monitor infant for constipation or feeding problems
observe infant for signs of bradycardia or hypotension
geriatric
elderlystart at 40% of adult dose
initiate therapy at low doses; titrate slowly; monitor for orthostatic hypotension and bradycardia
regular blood pressure and heart rate monitoring; renal function assessment
Use with caution and monitor for adverse effects.
pediatric_age
children under 12weight-based dosing required
use only for specific indications such as supraventricular tachycardia; limited pediatric formulations available
close cardiac monitoring; assess for adverse effects
Use with caution and monitor for adverse effects.
renal_impairment
mild to moderateno significant dose reduction needed
use with caution; monitor renal function
monitor renal function and electrolytes regularly
Use with caution and monitor for adverse effects.
renal_impairment
severereduce dose by 50%
use with caution; consider extended-release formulations
frequent monitoring of renal function, electrolytes, and blood pressure
Use with caution and monitor for adverse effects.
hepatic_impairment
mildreduce dose by 50%
use with caution; monitor for excessive hypotension
monitor blood pressure and heart rate closely
Use with caution and monitor for adverse effects.
hepatic_impairment
moderate to severereduce dose by 50-75%
use with extreme caution; avoid rapid IV administration
frequent blood pressure monitoring; ECG monitoring; liver function tests
Use with caution and monitor for adverse effects.
Statistics and clinical data
FDA approval year
Initial FDA approval for Verapamil
Drug class
ATC classification C08CA01
Primary indications
Main therapeutic applications
Mechanism of action
Primary pharmacodynamic action
Treatment of hypertension (high blood pressure), angina pectoris, and cardiac arrhythmias including supraventricular tachycardias, atrial fibrillation, and atrial flutter. Also used for cluster headache prophylaxis and sometimes migraine prevention.
Blocks calcium channels in cardiac muscle and vascular smooth muscle, preventing calcium from entering cells. This causes relaxation of arterial walls (reducing peripheral resistance and blood pressure), decreases cardiac contractility, slows heart rate, and prolongs conduction through the AV node.
Use cautiously in patients with heart failure, bradycardia, or AV block. May interact with beta-blockers, digoxin, statins, and many other medications. Avoid grapefruit juice as it can increase drug levels. Do not stop abruptly. Available in immediate-release and extended-release formulations; doses vary by formulation.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 24, 2026. · Read our editorial policy