1. Overview

• Generic name: Verapamil HCl
• Brand name: Verelan, Verelan PM, Isoptin SR and Calan
• Drug class: Calcium channel blockers

Verapamil is prescription medication which belongs to a class of medicine known as calcium channel blockers. It acts by blocking calcium influx into myocardial and vascular smooth muscle cells causing blood vessels relaxation.

Verapamil is used to treat high blood pressure and several other problems associated with the heart. It is available as tablets, capsules and injection.

2. Uses

Verapamil decreases heart rate, contractility of the heart and peripheral vascular resistance, hence it is used in the treatment of:

1. Hypertension (high blood pressure)
2. Angina (Chest pain)
3. Arrhythmias (irregular heartbeat)
4. Migraine (Vascular Headache)

3. Dosage forms

Verapamil is available as:

1. Injection Solution: 2.5 mg/ mL
2. Tablets: 40 mg, 80 mg, 120 mg
3. Extended-Release tablets: 120 mg, 180 mg, 240 mg
4. Extended-Release capsules: 100 mg, 120 mg, 180 mg, 200 mg, 240 mg, 300 mg, 360 mg

4. How & when to take verapamil

Verapamil should be taking with food at the same time each day. If you missed a dose you should take it as soon as possible.

Extended release tablets and capsules should not be crushed or divided.

Do not stop taking the drug before talking to your doctor. If you suddenly stop taking Verapamil, the symptoms may reappear.

5. Special precautions

Be sure to tell your doctor if:

• You are allergic to verapamil
• You have second- or third-degree heart block
• You have cardiac shock
• You have hypotension
• You have liver disorders
• You are taking other medications (e.g. beta-blocking agents)

Pregnancy and breastfeeding:
Verapamil is not recommended during pregnancy and breast feeding because it can cross placenta and pass into breast milk. Discuss with your doctor before using it.

Can I drive and do hazardous work while I’m using Verapamil?
Verapamil causes dizziness since the drug can lower blood pressure; therefore, it’s recommended to avoid those activities until you have found out how Verapamil affects you.

Can I drink Alcohol while using Verapamil?
Avoid drinking. Alcohol may cause dizziness by lowering blood pressure.

6. Who cannot use Verapamil?

Verapamil is not suitable for certain individuals who:

• Have renal or hepatic impairment
• Are hypersensitive to Verapamil
• Have severe hypotension (systolic less than 90 mm Hg)
• Have second- or third-degree AV block (also called heart block). Exception: when pacemaker is present.
• Are suffering from sick sinus syndrome without the presence of a pacemaker.
• Atrial fibrillation (e.g., Wolff-Parkinson-White Syndrome)
• Have heart problems (e.g. left ventricle dysfunction and heart failure)

Verapamil for infants and children is given only based on the doctor advice.

7. Side effects

The most common side effects of the drug are:

• Swelling of ankle
• Light-headedness
• Headache
• Constipation
• Vomiting
• Nausea

On rare occasions, you might have:

• Rash
• Bradycardia
• Dizziness

Verapamil side effects in details.

8. Interactions

Several drugs and substances can interact with Verapamil resulting in undesired effects. Interaction can affect activity of the drug or increase the severity of side effects.

Interactions with drugs
Verapamil can form drug-drug interactions with the following drugs:

• Beta blockers (e.g., carvedilol, metoprolol): using verapamil with these drugs will increase the risk of heart failure or arrhythmia.
• Carbamazepine, cyclosporine, digoxin, theophylline, sirolimus and ivabradine: verapamil increases the effect of these drugs. Avoid combination or reduce doses may be necessary.
• Rifampicin and barbiturates: effects of verapamil can be reduced by these drugs.
• Statins (e.g., Simvastatin & atrovastatin): using verapamil with these drugs will increase the risk of muscle damage.
• Clarithromycin and erythromycin: effects of verapamil is increased by these drugs.
• Colchicine: effects of colchicine is increased by verapamil. Combination must be avoided.

Interactions with Herbal medicine:
Ginseng, yohimbe, ephedra, ginger, licorice, black cohosh and periwinkle might make hypertension worse, Concentration or effects of Verapamil might be reduced by St. John’s wort.

Food interaction:
Grapefruit products can increase blood levels of Verapamil, so it should be avoided.