What is Diltiazem ER: Uses, Warnings & Interactions

How to take Diltiazem ER

• Take this drug as instructed. The dose may need to be changed several times to find what works best for you.

• Ask the prescriber or pharmacist if doses can be taken with or without food. It may vary between products.

• Swallow the capsule or tablet whole with a glass of water. Do not crush, break, chew, or open the capsule or tablet.

  • For people who cannot swallow a capsule, Tiadylt ER or Tiazac capsules can be carefully opened, the contents sprinkled over a spoonful of applesauce, and the doses taken that way. Swallow the mixture without chewing.

• Store diltiazem ER capsules in a closed, light-resistant container at room temperature. Protect the medicine from excessive humidity.

• Store diltiazem ER tablets in a closed, light-resistant container at room temperature. Protect the medicine from excessive humidity or temperatures hotter than 86˚F.

What to do if you miss a dose of Diltiazem ER

• Ask the prescriber how to handle a missed dose.

• Do not take extra medicine to make up for a missed dose.

Diltiazem ER contraindications

• This medicine is not right for everyone. 

• Do not use it if you have:

  • Known allergies to diltiazem

  • A heart rhythm problem called sick sinus syndrome without a pacemaker

  • Heart block

  • Low blood pressure

• Doctors never use diltiazem in people who are having a heart attack accompanied by fluid buildup in the lungs.

Diltiazem ER warnings

• Tell any doctor or other healthcare provider who treats you that you are using this medicine.

• The prescriber may need regular lab tests and office visits to check on the effects of this medicine. Keep all appointments.

• Before starting diltiazem treatment, tell the prescriber if you are pregnant, breastfeeding, or have:

  • Heart problems

  • Heart failure

  • Liver problems

  • Kidney problems

• This medicine may cause the following problems: 

  • Peripheral edema

  • Low blood pressure

  • Slow heart rate

  • Heart rhythm abnormalities

  • Heart attack

  • Worsening of heart failure

  • Liver injury

• This medicine could lower your blood pressure too much, especially when you first use it or if you are dehydrated. Stand or sit up slowly if you feel lightheaded or dizzy.

• Do not stop using this medicine without consulting with the prescriber.

Diltiazem ER interactions

• To avoid possible drug interactions, share with the prescriber a list of all the prescription drugs, over-the-counter medications, and supplements you use, particularly:

  • Other blood pressure drugs, especially beta blockers

  • Other drugs that treat heart rhythms or heartbeats, especially quinidine or digoxin

  • Cholesterol drugs called statins

  • Benzodiazepines like Valium (diazepam)

  • Barbiturates

  • Enlarged prostate medications called alpha blockers 

  • Cancer medications

  • Buspirone, carbamazepine, cimetidine, clarithromycin, clonidine, cyclosporine, ivabradine, lurasidone, rifampin

• Tell other healthcare providers about diltiazem treatment before they prescribe new medications.

  • Make sure the physician, surgeon, or healthcare team knows you are taking diltiazem before any surgery or medical procedure that requires general anesthetics or ketamine. Diltiazem may need to be discontinued a few days before the procedure.

• Avoid drinking alcohol or grapefruit juice when taking diltiazem.

Find more information about diltiazem drug interactions to avoid here.