• Basic Info
• Top Questions
• Clinical Info
• Interactions

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Symptoms of a verapamil overdose include dizziness, weakness, chest pain, shortness of breath, fainting, an unusually fast or slow heartbeat, coma, slurred speech, and confusion.

What should I avoid while taking verapamil?

Grapefruit and grapefruit juice may interact with verapamil. The interaction could lead to potentially dangerous effects. Discuss the use of grapefruit and grapefruit juice with your doctor. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Follow any recommendations your doctor makes about diet or exercise.

What are the possible side effects of verapamil?

• an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);

• an unusually fast or slow heartbeat;

• shortness of breath (heart failure);

• fainting;

• abnormal behavior or psychosis;

• jaundice (yellowing of the skin or eyes); or

• swelling of the legs or ankles.

Other, less serious side effects may be more likely to occur. Continue to take verapamil and talk to your doctor if you experience

• unusual headache, fatigue, or tiredness;

• insomnia or trouble sleeping;

• vivid dreams;

• hair loss;

• nausea or diarrhea; or

• increased urination.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect verapamil?

Before taking this medication, tell your doctor if you are taking any of the following drugs:

• cyclosporine (Sandimmune, Neoral);

• cimetidine (Tagamet, Tagamet HB);

• carbamazepine (Tegretol, Carbatrol);

• lithium (Lithobid, Eskalith, others);

• theophylline (Theo-Dur, Theochron, Theolair, Theobid, Elixophyllin, Slo-Phyllin, others);

• rifampin (Rifadin, Rimactane);

• phenobarbital (Luminal, Solfoton);

• an HMG CoA reductase inhibitor such as atorvastatin (Lipitor), lovastatin (Mevacor), simvastatin (Zocor), and others; or

• another heart medication such as propranolol (Inderal), metoprolol (Lopressor, Toprol XL), atenolol (Tenormin), digoxin (Lanoxin), quinidine (Quinora, Quinidex, Quinaglute), flecainide (Tambocor), disopyramide (Norpace), captopril (Capoten), enalapril (Vasotec), and others.

You may not be able to take verapamil, or you may require a dosage adjustment or special monitoring if you are taking any of the medicines listed above.

Drugs other than those listed here may also interact with verapamil or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including vitamins, minerals, and herbal products.

Where can I get more information?

Your pharmacist has additional information about verapamil written for health professionals that you may read.