Drug Interactions
Your healthcare professionals (e.g., 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 them first. This drug should not be used with the following medications because very serious interactions may occur: epinephrine for low blood pressure, metrizamide, sibutramine. If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting promethazine. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially: anticholinergics (e.g., benztropine, belladonna alkaloids), cancer chemotherapy (e.g., methotrexate), guanethidine, guanadrel. Tell your doctor or pharmacist if you have taken MAO inhibitors (e.g., furazolidone, isocarboxazid, linezolid, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine) within 2 weeks before, during or after using promethazine. Tell your doctor or pharmacist if you also take drugs that cause drowsiness such as: certain antihistamines (e.g., diphenhydramine), anti-seizure drugs (e.g., carbamazepine), medicine for sleep or anxiety (e.g., alprazolam, diazepam, zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., chlorpromazine, risperidone, trazodone). Check the labels on all your medicines (e.g., cough-and-cold products) because they may contain drowsiness-causing ingredients or other antihistamines. Ask your pharmacist about the safe use of those products. Also report the use of drugs which might increase seizure risk (decrease seizure threshold) when combined with promethazine such as bupropion, isoniazid (INH), phenothiazines (e.g., thioridazine), theophylline, tramadol, or tricyclic antidepressants (e.g., amitriptyline), among others. Consult your doctor or pharmacist for details. This medication may interfere with certain laboratory tests (including some pregnancy tests, blood sugar tests, skin test for allergies), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug. 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.