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Diltiazem - Uses, Dosage, Side Effects, Drug Warnings, and Precautions

Published on Jan 07, 2021   -  4 min read


Diltiazem is a drug that is used to treat high blood pressure and chest pain. Learn about its uses, dosage, drug warnings, side effects, precautions, drug interactions, and more.

Diltiazem - Uses, Dosage, Side Effects, Drug Warnings, and Precautions


Diltiazem is a drug that is given to prevent the patient from various cardiac conditions. The effective working of Diltiazem helps in keeping the blood flow in a proper condition. This drug needs a prescription for purchase. It can be used in combination with other drugs but requires a proper recommendation from your doctor. Diltiazem is a highly influential drug, and it should be kept away from children. If kids happen to consume these drugs by mistake, it can be really harmful to their health.

Drug Group:

Diltiazem is a drug belonging to the group called calcium channel blockers. This drug is known to produce a good antihypertensive effect. It can treat several grades of hypertension. The antihypertensive effect is due to the dilatation of the peripheral vessels. The peripheral vessels include the blood vessels in the hands, feet, legs, and arms. The other drugs belonging to this group are Verapamil, Nifedipine, Amlodipine, Isradipine, Nicardipine, and Felodipine.

What Is Diltiazem Used For?

Diltiazem is used in the treatment of:

  1. It is used in hypertension cases. Hypertension might seem like a common condition, but if it is left untreated, it can lead to damage to other organs such as the kidney, liver, blood vessels, and heart.

  2. Helpful for cardiac arrhythmias.

  3. Useful for chest pain or angina.

  4. Supraventricular tachycardia.

  5. Atrial fibrillation and atrial flutter.

  6. Prophylaxis for angina pectoris.

  7. Congestive heart failure.

Never take Diltiazem without consulting your doctor first.

How Does Diltiazem Work?

A certain level of calcium keeps moving through the calcium channels. These channels are responsible for electrical activity and conduction in the heart. When these channels are blocked, the conduction rate within the heart is reduced. The force of contraction in the heart is also reduced. The load on the muscle cells is reduced, resulting in the dilation of the arteries. When the vessels become enlarged and dilated, the pressure exerted by the heart is greatly reduced. This, in turn, reduces blood pressure. This is how the blood pressure is reduced in patients with hypertension. If the mechanism works properly, then hypertension can be controlled and brought back to a normal level.

Onset Of Action:

The onset of action refers to the time taken for a drug to start its potential effect. Diltiazem has a short duration of action. It can start acting within 15-30 minutes. Its peak response will be in the first hour or second hour after consumption.


There have been no reports of the habit-forming tendency in patients who are taking Diltiazem.

Expiry Date:

The drugs should not be consumed after the date has expired. The expiry date will be printed on the back of the medication pack.

What Is the Dosage of Diltiazem?

The dosage of this medication should be adjusted according to your weight, BMI, age, immunity condition, and other health conditions. Your doctor will ask you to take a minimum dose in the beginning. This will prevent the patient from developing drug tolerance.

Diltiazem dosage for adults:

Diltiazem dosage for adults

Diltiazem dosage for adults

How to Use Diltiazem?

This drug is available as a tablet and capsule. The normal tablet is taken three to four times a day. But the capsule can be consumed and can be taken only one or two a day. The tablet is a long-acting one. But the capsules are extended-release capsules. The drug levels of these drugs will stay in the body for a very long time. This is the advantage of an extended-release capsule. Both the capsule and tablet should be swallowed, and it should not be chewed. It is also administered in the form of a bolus injection. Bolus injection is the procedure by which the medicine is injected into the bloodstream through the catheter. In this way, medicine can quickly reach the blood.

Missed Dose:

If you miss a dose, you can take it anytime you remember it. But do not take a double dose as compensation for missed doses. Taking the dose at the regular timing is necessary.

What Are the Drug Warnings and Precautions?

Before taking these drugs, it is necessary for you to check with your doctor for the dosage of the drug.

Pregnancy: Calcium channel blockers are completely safe during pregnancy. This group of drugs is the only safe drug for hypertension. But pregnancy is the state where you need to stay extra careful. So, it is better to check with your doctor before taking these drugs.

Breastfeeding: There are no proper reports to prove that Diltiazem is not to be used in breastfeeding. However, you should ask your doctor to advise you on the usage of this drug.

Hypotension: Diltiazem is known to reduce the blood pressure further in a patient. So, this drug is contraindicated for patients with low blood pressure.

Liver: Diltiazem is known to cause an increase in enzymes such as alkaline phosphatase. This drug is, therefore, dangerous for patients with liver disorders as it might make the condition furthermore complicated.

Skin disorder: This drug might cause a few severe skin reactions in the patient. So, if you already have skin or any associated disorders, avoid taking these medications.

What Are the Side Effects of Diltiazem?

The common side effects of Diltiazem are nausea, vomiting, headache, dizziness, and a very slow heartbeat. This drug can also cause certain severe symptoms such as:

What Are the Interactions of Diltiazem?

Generally, a drug can react with

With medications:

With disease:

With alcohol:

In alcoholic patients, this drug can reduce blood pressure. So avoid consuming alcohol.

What Are the Common Brand or Trade Name of Diltiazem?

Consult a doctor if you have any doubts regarding the drug.


Frequently Asked Questions


What Is the Purpose of Diltiazem?

Diltiazem relaxes the blood vessels and muscles of your heart. Diltiazem is used to treat angina (chest pain), hypertension (high blood pressure), and certain heart rhythm disorders.


Is Diltiazem Dangerous?

Diltiazem can damage the kidneys, heart, and blood vessels of the brain, resulting in heart failure, kidney failure, or stroke. The risk of heart attacks may increase due to high blood pressure. These problems can be minimized if blood pressure is controlled. Diltiazem is a calcium channel blocker.


Is Diltiazem Hard on the Kidneys?

The kidneys are partially responsible for eliminating Diltiazem from the body. Reduced kidney function or kidney disease may cause this medication to build up in the body, thus causing side effects. Occasionally, Diltiazem may cause liver damage.


Is Diltiazem Safe to Take?

Diltiazem oral capsule is used for prolonged treatment. It comes with risks if you don't take it as prescribed. If you don't take it at all, if you don't take Diltiazem, your blood pressure and chest pain could worsen. This can lead to a stroke or heart attack.


Does Diltiazem Affect Sleep?

No data is indicating an association between Diltiazem and sleep disturbance. Although sleep disturbance is mentioned as a potential adverse effect in the product labeling of Diltiazem, it is not known to be a common side effect, occurring in less than 1% of patients treated.


Should I Take Diltiazem in the Morning or at Night?

At first, adults are allowed to consume 180 to 240 milligrams (mg) once a day. Medication can be consumed either in the morning or before bedtime. Doctors may adjust your dose based on the requirement.


Is Diltiazem a Good Blood Pressure Medicine?

Diltiazem is used to treat control angina (chest pain) and high blood pressure. Diltiazem is in a group of medications called Calcium-Channel blockers. It works by easing the blood vessels, so the heart does not have to pump as hard as required. It also enhances the supply of oxygen and blood to the heart.


Does Diltiazem Lower Heart Rate?

Diltiazem serves to relax the blood vessels in your body and heart. This decreases blood pressure. This pill also lowers the heart rate and dilates the coronary arteries.


Can Diltiazem Cause Liver Damage?

Diltiazem can cause moderate increases in liver function enzymes. In rare scenarios, it may cause sudden harm to the liver. This liver damage often goes away when you quit the medication.


What Drugs Can Replace Diltiazem?

Diltiazem can be replaced by the following drugs. They are:
- Metoprolol tartrate.
- Prazosin.
- Carvedilol.
- Amlodipine.
- Nifedipine.
- Hydrochlorothiazide.
- Lisinopril or Hydrochlorothiazide.
- Lisinopril.
- Valsartan.
- Clonidine.
- Verapamil.


Is Diltiazem a Diuretic?

There was no deterioration of symptoms due to congestive heart failure, such as dyspnea and increased body weight. It may be concluded that Diltiazem does not worsen congestive heart failure through its diuretic effect and probably its systemic vasodilating action.


Is Diltiazem Used for Anxiety?

If the heart palpitations are caused by anxiety, then your healthcare provider may prescribe an anti-anxiety medication called anxiolytic. These medicines will support you to relax. A few common drugs include Diltiazem.


When to Take Diltiazem?

Extended-release Diltiazem capsules must be taken on an empty stomach (which means 1hour before food or 2hours after food). Most other Diltiazem formulations can be taken either with or without food. However, you should always check the guidance on the label.


Can I Drink Alcohol With Diltiazem?

Alcohol can lower blood pressure and add to the effects of Diltiazem. A person may experience lightheadedness, dizziness, rapid heartbeat, or fainting if you drink alcohol with Diltiazem. These symptoms are experienced, especially when a person first starts taking the medication or just after a dose increase.


How to Stop Taking Diltiazem?

Do not stop taking Diltiazem immediately without consulting with the doctor. Or else, your condition may become more serious. Keep consuming this drug if you are being treated for high blood pressure, even if you feel well. High blood pressure often has no symptoms.

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Last reviewed at:
07 Jan 2021  -  4 min read




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