How the interaction occurs:
When these two medicines are taken together, your body may process methadone and morphine more quickly.
What might happen:
Your blood levels of methadone may decrease and cause drug withdrawal. Your blood levels of morphine may decrease and it may not work as well.
What you should do about this interaction:
If you are taking methadone and experience nausea, vomiting, stomach pain, diarrhea, irritability, sleep disturbances, or other symptoms, contact your healthcare professionals (e.g. doctor or pharmacist). Your doctor may want to adjust the dose of your medicine.If you are taking morphine and it doesn't seem to be working as well, contact your healthcare professionals. Your doctor may want to adjust the dose of your medicine.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Raistrick D, Hay A, Wolff K. Methadone maintenance and tuberculosis treatment. BMJ 1996 Oct 12;313(7062):925-6.
2.Holmes VF. Rifampin-induced methadone withdrawal in AIDS. J Clin Psychopharmacol 1990 Dec;10(6):443-4.
3.Kreek MJ, Garfield JW, Gutjahr CL, Giusti LM. Rifampin-induced methadone withdrawal. N Engl J Med 1976 May 13;294(20):1104-6.
4.Bending MR, Skacel PO. Rifampicin and methadone withdrawal. Lancet 1977 Jun 4;1(8023):1211.
5.Garfield JW, Kreek MJ, Giusti L. Rifampin-methadone relationship. 1. The clinical effects of rifampin-methadone interaction. Am Rev Respir Dis 1975;3:926.
6.Kreek MJ, Garfield JW, Gutjahr CL, Bowen D, Field F, Rothschild M. Rifampin-methadone relationship. 2. Rifampin effects on plasma concentration, metabolism, and excretion of methadone. Am Rev Respir Dis 1975;3:926-927.
7.Fromm MF, Eckhardt K, Li S, Schanzle G, Hofmann U, Mikus G, Eichelbaum M. Loss of analgesic effect of morphine due to coadministration of rifampin. Pain 1997 Aug;72(1-2):261-7.