Methotrexate/Penicillins Interactions
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Medical warning:
Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Penicillin antibiotics may decrease the ability of your kidneys to remove methotrexate from your body.
What might happen:
The levels of methotrexate in your body may increase and cause serious. possibly life-threatening, side effects.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want to monitor the amount of methotrexate in your blood, change the dose of your methotrexate, or change your antibiotic. Let your doctor know right away if you develop nausea, stomach pain, yellowing of the eyes or skin, dark urine, fever, fatigue, a persistent sore throat, easy bruising or bleeding, black stools, a change in the amount of urine you pass, skin rash, breathing problems, dry cough, diarrhea, or mouth sores while taking these medicines together or after finishing taking these medicine together.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.Ronchera CL, Hernandez T, Peris JE, Torres F, Granero L, Jimenez NV, Pla JM. Pharmacokinetic interaction between high-dose methotrexate and amoxycillin. Ther Drug Monit 1993 Oct;15(5):375-9.
- 2.Engelbrecht JA, Calhoon SL, Scherrer JJ. Methotrexate pneumonitis after low-dose therapy for rheumatoid arthritis. Arthritis Rheum 1983 Oct; 26(10):1275-8.
- 3.Mayall B, Poggi G, Parkin JD. Neutropenia due to low-dose methotrexate therapy for psoriasis and rheumatoid arthritis may be fatal. Med J Aust 1991 Oct 7;155(7):480-4.
- 4.Bloom EJ, Ignoffo RJ, Reis CA, Cadman E. Delayed clearance (CL) of methotrexate (MTX) associated with antibiotics and antiinflammatory agents. Clin Res 1986;34(2):560A.
- 5.Herrick AL, Grennan DM, Griffen K, Aarons L, Gifford LA. Lack of interaction between flucloxacillin and methotrexate in patients with rheumatoid arthritis. Br J Clin Pharmacol 1996 Mar;41(3):223-7.
- 6.Dean R, Nachman J, Lorenzana AN. Possible methotrexate-mezlocillin interaction. Am J Pediatr Hematol Oncol 1992 Spring;14(1):88-9.
- 7.Nierenberg DW, Mamelok RD. Toxic reaction to methotrexate in a patient receiving penicillin and furosemide: a possible interaction. Arch Dermatol 1983 Jun;119(6):449-50.
- 8.Yamamoto K, Sawada Y, Matsushita Y, Moriwaki K, Bessho F, Iga T. Delayed elimination of methotrexate associated with piperacillin administration. Ann Pharmacother 1997 Oct;31(10):1261-2.
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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.