What Is Diltiazem?

Diltiazem is part of the calcium channel blocker family of drugs and is used to treat high blood pressure. When taken regularly, it can encourage vasodilation due to relaxing the blood vessel’s muscular walls.

This medication is mostly available as an oral capsule or tablet and will be prescribed in different strengths. The typical strength range is between 30 mg and 300 mg per capsule.

You will see Diltiazem sold in the US under the brand name Cardizem.

How Does Diltiazem Work?

Diltiazem works by relaxing blood vessels and improving blood flow around your body. Relaxed and widened blood vessels allow blood to flow more freely and can reduce blood pressure. In turn, this enables your heart to do less work when pumping blood, reducing the chances of heart attacks and cardiovascular complications.

This drug is a calcium channel blocker, which means it blocks the flow of calcium ions into the cardiac muscle tissue. When the heart is full of too many calcium ions, it can be harder for it to pump blood, which increases blood pressure. Calcium channel blockers like Diltiazem allow the cardiac muscle to contract smoothly and in a more relaxed state, leading to the benefits mentioned above.

What Is Diltiazem Used For?

Due to the way it works, Diltiazem is used as a high blood pressure medication. It can significantly reduce blood pressure levels to a healthy state, which aids in the prevention of the following cardiovascular conditions:

• Coronary heart disease
• Heart attacks
• Strokes

Furthermore, Diltiazem is prescribed as a treatment to control angina (chest pain). Relaxing the blood vessels and improving the heart’s ability to pump blood around the body will stop chest pain from happening. It is sometimes used as a treatment for individuals who experience angina during exercise. Diltiazem stops the heart from overworking, which may increase a person’s capacity to exercise freely without chest pain.

What Are the Side Effects of Diltiazem?

Side effects should be expected when taking any new medication for the first time. In the case of Diltiazem, it produces mild-to-severe side effects depending on the person. The good news is that mild side effects are far more common and shouldn’t be met with any concern.

The following side effects do not require immediate medical attention and will likely go away or be easy to manage:

• Constipation
• Mild headaches
• Hot flushes
• Face redness
• Mild dizziness/lightheadedness

Should these symptoms persevere or get worse, then you should consult a doctor for guidance.

Some side effects can be more severe than the ones above and will need instant attention from a medical professional. Call your doctor if any of these symptoms are present after taking Diltiazem:

• Facial swelling
• Rashes on your body
• Fainting
• Extreme fatigue
• Shortness of breath
• Ankle swelling
• Sudden weight gain
• Slow heartbeat
• Low blood pressure
• Blistering skin

How to Take Diltiazem?

Diltiazem will be prescribed as an oral tablet that should be taken whole with a glass of water. It is not advised to crush or break the tablets before ingesting them. If you have difficulty swallowing oral tablets, speak with your doctor beforehand and they will help provide a solution.

The precise dose of Diltiazem will depend on your condition. As a general rule, the higher your blood pressure is, the higher your dosage will be. Always follow your doctor’s orders and do not take more than the required dose. Before obtaining your prescription you will also be told how often to take a tablet and how much time to leave between taking them. Stick to this schedule to see the best results.

It is usually recommended that you take your Diltiazem tablets on an empty stomach. This makes it more effective as the drug can be released better in your system and provide the full benefits.

You should only take Diltiazem for as long as prescribed by your doctor. If your blood pressure improves over time, you may no longer need this drug. Be sure to see your doctor for regular health checks and to constantly monitor your blood pressure. If there comes a time when your doctor says this medication is no longer required, stop taking it.

Please be aware that Diltiazem is not a cure for high blood pressure. It will help to lower your blood pressure levels, but you should also commit to long-term lifestyle changes to maintain a healthy blood pressure. Speak to your doctor about making the necessary changes and they will recommend things based on your situation and what will likely work best for you.

Frequently Asked Questions About Diltiazem

Who Should Not Take Diltiazem?

You should not take Diltiazem if:

• You are allergic to this drug or any ingredients in it.
• If you have certain heart problems, such as hypotension, acute myocardial infarction with pulmonary congestion, second or third-degree atrioventricular block, or sick sinus syndrome.
• Pregnant or breastfeeding
• Have liver disease
• Have kidney disease

The listed above are not the only conditions in which you should not take this medication. Discuss your health and medical history with your doctor to ensure Diltiazem is safe for you to take.

What Is the Most Common Side Effect of Diltiazem?

The most common side effect of Diltiazem is edema, or swelling of the hands, feet, ankles, and face. This is caused by fluid retention in these areas because the drug relaxes the blood vessels and reduces blood pressure.

Other common side effects may include:

• Dizziness or lightheadedness
• Flushing
• Headache
• Fatigue or weakness
• Nausea

Note that the list above does not include all of the potential side effects of Diltiazem. If you experience any other symptoms, talk to your doctor immediately.

It is important to keep in mind that everyone’s body reacts differently to medication. While some people may experience few or no side effects with Diltiazem, others may be more sensitive and have stronger reactions.

What to Avoid While Taking Diltiazem?

While taking Diltiazem you should avoid the following:

• Grapefruit – Grapefruit products can increase the levels of diltiazem in your blood, enhancing its effects and side effects.
• Alcohol – Drinking alcohol while taking diltiazem can lower your blood pressure further and may increase the risk of dizziness or fainting.
• Other blood pressure medication – Taking diltiazem with other medications that lower blood pressure can increase the risk of hypotension.

The list above does not include all of the potential interactions between Diltiazem and other substances. Be sure to discuss with your doctor any other medications you are taking, including over-the-counter ones, natural supplements, or herbal remedies.

How Long Does It Take for Diltiazem to Work?

Diltiazem is quite a fast-acting drug and it should start working almost immediately after taking it. The full effects of this drug can take up to a week or two to appear, but you should begin to feel it helping with your blood pressure levels shortly after taking it.

However, this also depends on factors like how severe the high blood pressure is and what other medications are being taken at the same time. A doctor will be able to give you more information about what to expect in your individual case.

Take care to follow instructions regarding how often and when to take the medication. Taking it at the wrong time or not following a schedule may reduce its effectiveness and prevent you from seeing any improvements in your condition.

It is also important that Diltiazem is taken for as long as prescribed by your doctor, even if you begin to feel better after a few days of taking it.

What Is the Typical Dosage for Diltiazem?

The exact dosage of Diltiazem will depend on a range of factors and your doctor will be the one to decide what dosage is best for you.

Generally, it is prescribed at first in a low dose and then gradually increased to higher doses if needed. The typical starting dose is 30 mg taken four times a day. The dosage can be increased up to 360 mg a day.

Can You Buy Diltiazem Over-The-Counter (OTC)?

No, you can not purchase Diltiazem over-the-counter (OTC). This drug is only available with a valid prescription from a doctor or other healthcare provider.

Can You Get Diltiazem Online?

Yes, you can get an online prescription for Diltiazem from DrHouse. Our licensed physicians are able to conduct virtual consultations and prescribe Diltiazem if deemed appropriate after reviewing your medical history and current condition.

Can I Get a Refill for Diltiazem From DrHouse?

Yes, you can get a prescription refill for your existing diltiazem RX from DrHouse if deemed appropriate by our licensed physicians after reviewing your medical history and current condition.

For more detailed information about Diltiazem, you can refer to the following sources:

• Diltiazem prescription label, Food and Drug Administration (FDA).
• Diltiazem, Drugs.com.
• Diltiazem, U.S. National Library of Medicine.

The content on this page has been medically reviewed for accuracy and comprehensiveness by Amy Dougherty, FNP-BC, AGAC