Diltiazem (Intravenous)


Diltiazem works by affecting the movement of calcium in the heart cells or blood vessels, hence increasing the supply of oxygen and blood in the heart. However, Diltiazem is a part of a full treatment program that involves other medications, diet, and exercise. A few side effects may be experienced when taking the drug to manage heart and chest conditions, but often no symptoms are reported for blood pressure.

Conditions Treated

Type Of Medicine

  • Calcium-channel broker

Side Effects

The common side effects experienced by Diltiazem users are congestion, fever, dryness, throat soreness, and dryness, runny nose, and hoarseness. Other patients have reported trouble when swallowing, voice changes and swollen or tender neck glands.

Diltiazem also has other worth mentioning less common side effects like a headache, loss of appetite, joint pains, flushing or skin redness especially in the eyes, shivering nausea, sleeping troubles, vomiting, and diarrhea.

There are side effects that might appear though they do not necessarily need medical attention. Most of them go away after several days of consuming the drug as the body adjusts to it. Also, your doctor or health care professional may tell you various ways of reducing or preventing the side effects.

Diltiazem may sometimes cause unwanted effects. Although not all them may occur, you should visit your medical practitioner if you experience confusion, blurred vision, irregular heartbeat, and decreased urine output, palpitations, dilated neck veins, extreme fatigue or wheezing.

Some patients have reported rare experiences after consuming the drug, such as bleeding, burning, infection, numbness, rashes, ulceration, scarring, hives, change of vision, loss of strength, constipation and impaired vision. Most of these symptoms are considered to be allergic reactions, but medical attention should be sought if they persist.


Like the other drugs, Diltiazem should be infused as per the doctor's prescriptions. The injection frequency should also be observed, hence the drug should not be used any longer even if the supply is still available.

Close attention to the doctor's prescription on the injections is required since the dosage will be given depending on the patient's needs. The instructions indicated on the bottle can still be followed since they should be similar to the physicians'. Some factors are considered by the physician while prescribing the dosage; the number of daily dosages, the strength of the drug, period of taking medicine and the time between the injections. The dosage can also depend on the main reason why the patient is prescribed Diltiazem.

Diltiazem manufacturers have provided the general dosage and instructions that should be followed; although in some cases the doctor may change these recommendations. This is because factors discussed between the patient and the doctors are the primary determiners of the frequency and dosage of the Diltiazem.

This drug is administered either by direct intravenous single injection or continuous intravenous infusion.

For direct intravenous injections:

The first dose should be 0.25mg/kg administered for more than two minutes. If there is an inadequate response, the second dose is administered after 15 minutes. The second Diltiazem bolus is, however, 0.35mg/kg of the actual body weight. Subsequent intravenous boluses should be administered according to the condition of the patient. Individuals with relatively lower body weights need to give a dosage on mg/kg basis.

For continuous intravenous infusion:

Diltiazem hydrochloride is administered to the patients with a continuous heart rate reduction (up to 24 hours). 0.25mg/kg or 0.35mg/kg bolus administration is injected to reduce the heart rate. The recommended initial intravenous infusion is 10mg/h, but it may be increased up to 15mg/h if further heart rate reduction is required. The injection is maintained up to 24hrs. The infusion rates that exceed 15mg/h are not recommended

Diltiazem injection should be well diluted for the continuous intravenous infusion to meet the desired volume of D5W, Normal Saline, or D5W/0.45%NaCl. Mix thoroughly and store in a refrigerated area.

The doctor determines the children's intravenous injection and use. If a dose of Diltiazem is missed, it should be taken as soon as possible. However, if the time for the next infusion is almost, the missed injection can be skipped and go back to the usual infusions. Double doses should not be done. No adequate studies if it's safe to use the drug in pregnancy have been commenced, but it is excreted in the breast milk hence breastfeeding mothers are not advised to use it.

If the patient gets signs like increased or decreased heartbeat, unconsciousness, coordination loss or flushed skin, immediate attention is required. Either call 911 or 1-800-222-1222 (poison control center) immediately.


In the human body, drugs interact with the others to change the effects of each medication. This may cause a dangerous reaction in the patient's body or make a particular drug to be ineffective. It is therefore crucial for the patients to have a list of the medications they are currently taking, their dosage and intake frequency. It's important to notify your health practitioner of the medicines that you are now taking, even the over the counter drugs. The doctor will be able to determine the drugs that do not interact well with the others.

Below are the drugs that have negatively interacted with Diltiazem. If a patient is currently taking any of these drugs, he /she should inform the doctor before taking Diltiazem first dose.

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    • Beta blockers like Labetalol, Atenolol, Metoprolol, and Nadolol.
    • Benzodiazepines like Midazolam and Triazolam
    • Buspirone (Buspar)
    • Carbamazepine (Epitol, Carbatrol, and Tegretol)
    • Quinidine (Quinidex)
    • Rifampin (Rifamate, Rifadin, Rimactane, Rifater)

Other interactions

  • Grapefruit and grapefruit juice also interact with Diltiazem. Your physician may advise you to have a low sodium diet during the period that you will be taking the drug.
  • You should avoid direct sunlight as the drug may increase the sensitivity of the skin and cause com/health/burns/">sunburns.

Diltiazem injection has been tested and found to be compatible chemically stable and physically compatible with most parenteral solutions once stored for more than 24 hours in PVC bags or glass under controlled temperatures. The patients are advised to tell their doctors if there is something they are taking that induces drowsiness. For instance, marijuana and alcohol, cough suppressants or sleeping pills contain hydrocodone. The doctor should also be informed of any drug taken for relaxation purposes or reducing anxiety. Each medication has an ingredient listing which the patient should make sure they go through them since some medicines have ingredients that are meant to cause downiness.


A patient should let the doctor know his/ her medical history, other medicines been taken currently, herbal supplements or vitamins. Before starting Diltiazem treatment, the warnings should be well understood to prevent the occurrence of any complications. For example, Diltiazem is not taken by everyone. The doctor should be notified if you have:

The warnings also extend to pregnant and lactating mothers as well as people with specific allergies.
Diltiazem slows down the heart rate. This can affect people with any arrhythmias type or people who take drugs to decrease the heart rate. In some cases, it has been reported to cause edema (retention) which is dangerous to the patients with congestive heart failure. Diltiazem can sometimes lower the blood pressure hence symptoms as fainting and dizziness should immediately be notified to doctor. The drug may increase the liver enzymes which can cause liver damage. Additionally, Diltiazem is metabolized and excreted by the liver and kidneys hence it may accumulate in the body of patients who have kidney diseases. Your doctor should carefully monitor and decrease the drug dosage if it has adverse body reactions.

Patients should not take alcohol while under Diltiazem medication especially. Due to the dizziness and drowsiness associated with the drug, the patient should not lift heavy machinery or drive automobiles. The drug may simulate intoxication hence the patients are advised to be cautious on their movements after taking it.


Diltiazem should be kept in a tightly closed container that it comes with. Store in a room temperature away from children and excess heat (do not store in the bathroom).

Medications that are no longer needed should be disposed of in places that can't be reached by children as most of the containers ( like creams, inhalers, and patches) are nonchild- resistant and they can easily be opened. To prevent the kids from getting poisoned, always lock safety caps and store the drug in a safe location.

The unneeded drugs should be disposed of in such a way that other people or pets cannot consume them. However, they should not be flushed down the toilet. The best disposal method is by use of medicine take-back program. Contact your pharmacist or local recycling department to know more about the local take-back programs.


Diltiazem is an essential and useful drug that controls hypertension, blood pressure, angina pectoris and arrhythmia. However, it may sometimes pose a significant risk when the when the instructions are not followed well or when the patient does not communicate well with the physician.

When taken in the correct dosage and frequency, Diltiazem takes up to two weeks for the patient to experience the full drug's benefit. The doctor should, however, be informed of any previous heart attack, low blood pressure or liver, and kidney disease. Prolonged side effects raise a significant concern that should be reported to the health provider immediately.

Various drugs do not interact well with Diltiazem medication, and therefore the Patient should maintain honesty when discussing the issue with the health provider. Your condition may worsen if you stop taking the drug suddenly without consulting the doctor. It's also important to note that Diltiazem sometimes impairs your reactions or thinking hence you should not commit yourself to something that requires you to be alert like driving.

To be confident that the drug is helping you; your blood pressure needs to be often checked. Your kidney and liver will also be tested regularly. Hence it's essential to visit the doctor on a regular basis.