Diltiazem is a calcium channel blocker. It works by relaxing the muscles of your heart and blood vessels.
Diltiazem is used to treat hypertension (high blood pressure), angina (chest pain), and certain heart rhythm disorders.
Diltiazem may also be used for purposes not listed in this medication guide.
What should you know before taking diltiazem?
You should not use diltiazem if you are allergic to it, or if you have:
- A serious heart condition such as “sick sinus syndrome” or “second- or third-degree AV block” (unless you have a pacemaker);
- Very low blood pressure; or
- If you have recently had a heart attack and you have a build-up of fluid in your lungs.
To make sure diltiazem is safe for you, tell your doctor if you have:
- Kidney disease;
- Liver disease;
- Congestive heart failure; or
- If you also take digoxin, or a beta blocker (such as atenolol, carvedilol, metoprolol, propranolol, sotalol, and others).
It is not known whether diltiazem will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.
Diltiazem can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.
Get emergency medical help if you have signs of an allergic reaction to diltiazem: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
- slow heartbeats;
- pounding heartbeats or fluttering in your chest;
- a light-headed feeling, like you might pass out;
- shortness of breath (even with mild activity), swelling, rapid weight gain;
- nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
- severe skin reaction – fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Common diltiazem side effects may include:
- dizziness, weakness;
- nausea; or
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
What other drugs will affect diltiazem?
Many drugs can interact with diltiazem, and your doctor may need to change your treatment plan if you use certain other medicines. The following are common drugs that interact with diltiazem:
- Medications used in anesthesia;
- Anti-anxiety medications called benzodiazepines (such as midazolam, triazolam, and others) as well as busipirone;
- Beta-blockers (such as atenolol, carvedilol, metoprolol, propranolol, sotalol, and others);
- Rifampin; and
- Cholesterol medication called statins (such as atorvastatin, lovastatin, simvastatin, rosuvastatin, and others)
Not all possible interactions are listed in this medication guide.
Other prescription and over-the-counter medicines, vitamins, and herbal products may interact with diltiazem. Tell your doctor about all medicines you use, and those you start or stop using. Give a list of all your medicines to any healthcare provider who treats you.