verapamil hydrochloride at a glance
Medicine class
Rate-limiting calcium channel blocker
Main roles
High blood pressure, angina and selected supraventricular heart rhythms
Available forms
Modified-release tablets, oral solution and hospital-administered injection
What is verapamil hydrochloride used for?
Licensed indications vary by formulation and product.
Treatment of mild to moderate hypertension.
Treatment and prevention of angina.
Treatment and prevention of paroxysmal supraventricular tachycardia, and control of ventricular rate in atrial flutter or fibrillation, with oral solution or intravenous injection as specified by the product licence.
Secondary prevention after myocardial infarction in carefully selected patients without heart failure when beta-blockers are unsuitable, as licensed for Half Securon SR.
Specialists may prescribe verapamil to help prevent cluster headache as a non-licensed use.
How does verapamil hydrochloride work?
Verapamil limits calcium entry into heart muscle, cardiac conduction tissue and vascular smooth muscle. This slows conduction through the atrioventricular node and can reduce heart rate and cardiac workload, while widening arteries and improving coronary blood flow.
verapamil hydrochloride preparations and strengths
Oral solution
Route: Oral
Strengths: 40 mg/5 mL
Tablet
Route: Oral
Strengths: 120 mg, 240 mg
Injection
Route: Parenteral
Strengths: 2.5 mg/mL
How to take verapamil hydrochloride
Follow the dispensing label and leaflet for the exact product supplied.
Swallow modified-release tablets with water; do not chew or crush them.
Use the supplied oral syringe or measuring spoon for liquid verapamil, not a kitchen teaspoon.
Food instructions differ between products; follow the leaflet supplied.
Avoid grapefruit and grapefruit juice because they can increase verapamil exposure.
Injection is given by healthcare professionals with cardiac and blood-pressure monitoring.
verapamil hydrochloride side effects
Common or expected effects
- Constipation
- Feeling or being sick
- Headache
- Dizziness or tiredness
- Flushing
- Ankle or peripheral swelling
Get urgent medical advice
- Severe allergic reaction, including facial or throat swelling or breathing difficulty
- Marked bradycardia, fainting, heart block or a new irregular heartbeat
- New or worsening heart failure symptoms, such as breathlessness or leg swelling
- Persistent chest pain or symptoms suggesting myocardial infarction
- Yellow skin or eyes or dark urine, suggesting liver injury
- Severe blistering or widespread skin reaction
verapamil hydrochloride in pregnancy
Verapamil can be used during pregnancy when clinically necessary, but is not commonly chosen for hypertension in pregnancy. Treatment for angina or an arrhythmia should be reviewed jointly by obstetric and cardiac specialists; do not stop it before that review. Available evidence has not identified clear pregnancy risks from calcium channel blockers, although experience with verapamil is limited compared with some alternatives.
verapamil hydrochloride while breastfeeding
Verapamil is a preferred rate-limiting calcium channel blocker during breastfeeding when the infant is full-term and healthy because milk transfer is negligible. As a precaution, monitor for unusual sleepiness, pallor, poor feeding or inadequate weight gain; seek individual advice for premature or unwell infants.
verapamil hydrochloride interactions
Verapamil affects cardiac conduction and inhibits CYP3A4 and P-glycoprotein, creating important interactions.
Ivabradine
The combination is contraindicated because of additive heart-rate reduction.
Beta-blockers
Additive bradycardia, hypotension, atrioventricular block or heart failure may occur; intravenous beta-blockers must not be given with intravenous verapamil.
Common questions about verapamil hydrochloride
Answers are fully visible for fast scanning and source review.
What is verapamil hydrochloride used for?
Depending on the product, it is used for high blood pressure, angina, selected rapid supraventricular heart rhythms and a restricted role after myocardial infarction.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.