Verapamil

Sounds like 'ver-AP-a-mil'

Easy-to-read medicine information about verapamil – what is it, how to take verapamil safely and possible side effects.

Type of medicine Also called
  • Antihypertensive (to lower blood pressure)
  • Used to prevent chest pain (angina)
  • Belongs to a group of medicines called calcium channel blockers
  • Isoptin®
  • Isoptin SR®
  • Verpamil SR®

What is verapamil?

  • Verapamil is used to treat high blood pressure (hypertension) and to prevent chest pain (angina). It may help to increase your ability to exercise and decrease how often you may get angina attacks.
  • Verapamil may also be used to control your heart rate if you have a fast or irregular heartbeat (such as atrial fibrillation).
  • It works by blocking calcium channels in the body, and in that way relaxes blood vessels and lowers blood pressure.
  • It belongs to a group of medicines called calcium channel blockers.
  • Verapamil is available as immediate release tablets or modified release tablets.

Dose

  • The dose of verapamil will be different for different people.
  • Verapamil is available in 2 forms - as immediate release tablets or modified release tablets. Check with your pharmacist which version you are taking.
  • Always take your verapamil exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much verapamil to take, how often to take it, and any special instructions.
  • Each time you collect a new supply of verapamil, check to make sure you have been given the same type of tablets as before.

How to take verapamil

  • If you are prescribed the immediate release tablets, take these as you have been prescribed (usually 2 or 3 times a day). Take your doses at the same times each day.
  • If you are prescribed the modified release tablets,  take these as you have been prescribed (usually once or twice a day). Take your doses at the same times each day. Swallow the modified release tablets whole, with a glass of water. Do not crush or chew them.
  • You can take verapamil with or without food.
  • Limit or avoid drinking alcohol while you are taking verapamil. Alcohol may increase your chance of side-effects, such as feeling dizzy or light-headed.
  • If you forget your dose, take it as soon as you remember that day. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.
  • Do not stop taking verapamil suddenly; speak to your doctor or nurse before stopping.

Possible side effects

Like all medicines, verapamil can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Constipation
  • Constipation is quite common
  • Ask your doctor to prescribe a suitable laxative, which you need to take on a regular basis
  • You also need to eat more fruit, vegetables, brown bread, bran based breakfast cereals and drink plenty of water
  • Headache
  • This is quite common when you first start taking verapamil, and usually goes away with time
  • Tell your doctor if troublesome 
  • Dizziness
  • Feeling light-headed
  • Feeling faint when you stand up
  • This is common when you first start taking verapamil and usually goes away with time
  • Be careful when getting up from either lying down or sitting to avoid falls
  • Avoid drinking alcohol
  • Changes in your heart beat (either too slow, too fast or irregular)
  • Chest tightness
  • Wheezing or trouble breathing
  • Swelling of the ankles or feet
  • Tell your doctor immediately or ring HealthLine 0800 611 116

Interactions

  • Check with a pharmacist before taking over the counter medicines such as:
    • Cold or flu tablets containing phenylephrine (e.g. Sudafed PE), or diphenhydramine (e.g. Benadryl Original)
    • Anti-inflammatories such as diclofenac (e.g. Voltaren Rapid), ibuprofen (e.g. Nurofen), mefenamic acid (e.g. Ponstan), naproxen (e.g. Naprogesic)
  • Verapamil may interact with a few medications and herbal supplements, so check with your doctor or pharmacist.

Learn more

The following links provide further information on verapamil.

Medsafe Consumer Information Sheet:
Isoptin
Isoptin SR
Verpamil SR

 

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr J Bycroft. Health Navigator NZ Last reviewed: 15 Sep 2015