Table of Contents
- What is Diltiazem Hydrochloride?
- Medical Uses of Diltiazem
- How Diltiazem Works
- Forms and Administration
- Potential Side Effects
- Drug Interactions
- Ongoing Research and Potential New Uses
What is Diltiazem Hydrochloride?
Diltiazem hydrochloride is a medication that belongs to a class of drugs called calcium channel blockers. It is also known by several brand names, including Cardizem, Cartia XT, and Matzim LA[7]. Diltiazem works by affecting how calcium moves into the cells of your heart and blood vessels, which can help relax and widen these vessels[1].
Medical Uses of Diltiazem
Diltiazem is used to treat several cardiovascular conditions:
- Hypertension (High Blood Pressure): Diltiazem helps lower blood pressure by relaxing blood vessels[3].
- Angina (Chest Pain): It can help prevent and treat chest pain caused by reduced blood flow to the heart[2].
- Heart Rate Control: Diltiazem is used to control rapid heartbeats in certain types of arrhythmias (irregular heart rhythms)[3].
- Coronary Artery Spasm: It can help prevent spasms in the arteries that supply blood to the heart[3].
Researchers are also exploring its potential use in other conditions, such as:
- COVID-19: Studies are investigating whether diltiazem could help treat pneumonia caused by COVID-19[1].
- Anal Fissures: When applied as a cream, diltiazem may help treat chronic anal fissures (painful tears in the lining of the anal canal)[4].
- Pulmonary Arterial Hypertension: Some research is looking at its potential in treating high blood pressure in the lungs[5].
How Diltiazem Works
Diltiazem works by blocking the entry of calcium into certain cells in your heart and blood vessels. This action has several effects[1]:
- It relaxes and widens blood vessels, making it easier for blood to flow through them.
- It reduces the workload on your heart, which can help relieve chest pain (angina).
- It can slow down rapid heart rates in some types of arrhythmias.
Forms and Administration
Diltiazem comes in several forms:
- Oral tablets or capsules: These can be immediate-release or extended-release formulations[3].
- Intravenous (IV) injection: This form is typically used in hospital settings for rapid effect[6].
- Topical cream: Used for treating anal fissures[4].
The dosage and frequency of administration depend on the condition being treated and the individual patient’s response. Always follow your doctor’s instructions carefully.
Potential Side Effects
Like all medications, diltiazem can cause side effects. Common side effects may include[4][7]:
- Dizziness
- Headache
- Slow heart rate
- Swelling in the legs or ankles
- Constipation
More serious side effects are rare but can occur. Contact your doctor immediately if you experience severe dizziness, fainting, or signs of heart problems.
Drug Interactions
Diltiazem can interact with other medications. It’s particularly important to be aware of its interactions with:
- Statins: Diltiazem can increase the levels of certain cholesterol-lowering medications in the blood[3].
- Other heart medications: It may interact with other drugs used to treat heart conditions.
Always inform your healthcare provider about all medications, supplements, and herbal products you are taking.
Ongoing Research and Potential New Uses
Researchers are continually studying diltiazem to understand its full potential. Some areas of ongoing research include:
- COVID-19 treatment: Studies are investigating whether diltiazem could help treat pneumonia caused by COVID-19 by stimulating the immune response in infected respiratory cells[1].
- Coronary microvascular dysfunction: Research is exploring its effectiveness in improving blood flow in small blood vessels of the heart[2].
- Jervell and Lange-Nielsen Syndrome: A rare heart rhythm disorder where diltiazem’s effects on heart electrical activity are being studied[6].
These studies may lead to new approved uses for diltiazem in the future, potentially benefiting more patients with various conditions.



