Diltiazem

💊 What is Diltiazem used for?

• •Treatment of high blood pressure (hypertension), to lower blood pressure. The label says this can reduce the risk of strokes and heart attacks. It can be used alone or with other blood pressure medicines.
• •Improving exercise tolerance in people with chronic stable angina, which is chest pain that happens in a predictable pattern.

How it works

The label describes diltiazem as a calcium channel blocker but does not explain its effects in more detail.

How it is usually taken

• •Take the tablet once a day at about the same time each day.
• •Swallow the tablet whole. Do not chew or crush it.
• •Follow the instructions from your prescriber or pharmacist about how much to take and how long to take it.

Comes as

• •Extended-release tablets of 120 mg, 180 mg, 240 mg, 300 mg, 360 mg, or 420 mg.
• •White to off-white, capsule-shaped, film-coated tablets. Each strength has its own imprint code.

⚠️ Diltiazem side effects

🛑 Who should not take Diltiazem, and who should be careful

The label says not to take it if

• 🚨You have sick sinus syndrome, unless you have a working ventricular pacemaker.
• 🚨You have second- or third-degree AV block, unless you have a working ventricular pacemaker.
• 🚨Your systolic blood pressure is below 90 mm Hg.
• 🚨You have had a reaction to diltiazem (hypersensitivity).
• 🚨You have an acute heart attack (acute myocardial infarction) with a condition the label lists as 'pulmonary.' The label text is incomplete here, so ask your prescriber to explain this contraindication.

Tell your doctor before taking it if

• •Tell the prescriber about all your medicines, including over-the-counter products and nutritional supplements such as St John's wort. The label says to talk with your prescriber before taking or stopping any other medicine.
• •Tell your prescriber if you have heart rhythm problems, a slow heart rate, heart failure, or liver problems. The label says the medicine can cause these problems.
• •Tell your prescriber if you are pregnant, may become pregnant, or are planning to become pregnant.

🔀 Diltiazem with other medicines, food and alcohol

The label says to discuss these with your doctor or pharmacist

• •Beta-blockers and digitalis can add to the effects of diltiazem on heart rate and heart conduction. The label says this may increase the risk of low blood pressure, slow heart rate, and heart failure.
• •Other medicines that affect heart contraction or conduction may also increase these risks.
• •Ivabradine: the label says to avoid using it together with diltiazem.
• •Diltiazem affects the CYP450 3A4 enzyme system. The label says medicines processed by this system may need dose adjustment. People with kidney or liver impairment may be at particular risk of changes in drug levels.
• •St John's wort: the label tells patients to consult their prescriber before taking it.

Alcohol and food

The label does not say.

🤰 Diltiazem in pregnancy and breastfeeding

Pregnancy

The label says published data from decades of use have not identified a drug-associated risk of major birth defects or miscarriage. Animal studies at doses related to the maximum recommended human dose showed embryo-fetal deaths and skeletal abnormalities, and an increase in stillbirths at a higher multiple. The label says to talk with your prescriber if you become pregnant or plan to become pregnant.

Breastfeeding

The label does not say.

🗓️ Storage, missed doses and taking too much

Storage

Store at room temperature, between 68°F and 77°F (20°C to 25°C). Short excursions between 59°F and 86°F (15°C to 30°C) are allowed. Avoid high humidity and temperatures above 86°F (30°C). Keep in a tight, light-resistant container.

If a dose is missed

The label does not say.

If too much is taken

The label reports that the toxic dose in people is not known and that blood levels can vary widely, which limits their usefulness in overdose cases. It describes 29 reports of diltiazem overdose, with 22 people recovering and seven fatal outcomes. If an overdose is suspected, seek emergency medical help right away. The label text provided does not describe specific treatment steps.

🗒️ Questions to ask about Diltiazem

• How much diltiazem should I take, and how long should I take it?
• Is it safe for me to take diltiazem with my other medicines and supplements, including St John's wort?
• Do I have a sick sinus syndrome, heart block, or low blood pressure that could affect whether I can take this medicine?
• What signs of liver problems or severe skin reactions should I watch for, and who should I call?
• What should I do if I become pregnant or plan to become pregnant while taking this medicine?
• Can I break or crush this tablet if I have trouble swallowing it?

❓ Diltiazem: frequently asked questions