Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: amiodarone, digoxin, fingolimod.
Other medications can affect the removal of diltiazem from your body, which may affect how this medication works. Examples include atazanavir, cimetidine, quinidine, St. John's wort, azole antifungals such as ketoconazole, macrolide antibiotics such as erythromycin, rifamycins including rifabutin and rifampin.
Diltiazem may also affect how your body gets rid of many drugs (such as buspirone, cyclosporine, sirolimus, certain statins including lovastatin and simvastatin, certain anti-seizure drugs including carbamazepine, certain benzodiazepines including triazolam and midazolam).
Check the labels on all your medicines (such as cough-and-cold products, diet aids, nonsteroidal anti-inflammatory drugs-NSAIDs such as ibuprofen for pain/fever reduction) because they may contain ingredients that could increase your blood pressure or heart rate. Ask your pharmacist about using those products safely.
Cimetidine is a nonprescription drug that is commonly used to treat extra stomach acid. Because cimetidine may interact with diltiazem, ask your pharmacist about other products to treat extra stomach acid.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.