Verapamil
Also sold as: Isoptin, Calan
Usual adult dose
Usual adult dose: 80 to 120 mg three times a day, or long-acting tablets 240 to 480 mg a day. For heart rhythm problems the dose is set by your doctor.
Your doctor may give you a different dose. Children's doses depend on weight.
Side effects
Common
- constipation
- dizziness
- headache
- swollen ankles
Serious — get help
Stop taking it and see a doctor straight away if you notice:
- very slow heartbeat
- fainting
- worsening heart failure
Do not take it, or take care, if
- Very slow heartbeat or heart block
- Heart failure with weak heart muscle
- Low blood pressure
- Taking a beta blocker (dangerous combination)
Interactions
Medicines that can react with this one.
Serious9 medicinesDo not take these together unless your doctor says so.
- Atenolol
Verapamil with a beta blocker can cause very slow heartbeat, heart block and heart failure.
- Bisoprolol
Together they can cause very slow heartbeat, heart block and heart failure.
- Carvedilol
Together they can cause very slow heartbeat, heart block and heart failure.
- Digoxin
Verapamil raises digoxin levels and can cause toxicity and heart block.
- Labetalol
Together they can cause very slow heartbeat, heart block and heart failure.
- Metoprolol
Verapamil with a beta blocker can cause very slow heartbeat, heart block and heart failure.
Show 3 more
- Propranolol
Together they can cause very slow heartbeat, heart block and heart failure.
- Simvastatin
Verapamil raises simvastatin levels and the risk of muscle damage.
- Timolol
Together they can slow the heart too much.