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.
Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Leucovorin may protect certain bacteria from the effects of your antibiotic.
What might happen:
If you are taking your antibiotic to treat or prevent Pneumocystis jiroveci pneumonia (formerly called Pneumocystis carinii or PCP), it may not work as well.
What you should do about this interaction:
Sometimes these medicines are used together to treat certain side effects of your antibiotic. If you have questions about your medicine, discuss them with your healthcare professionals (e.g. doctor or pharmacist). If you are taking your antibiotic to prevent or treat Pneumocystis jiroveci pneumonia (formerly called Pneumocystis carinii or PCP), let your doctor know right away if your condition does not improve or gets worse.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.Nunn PP, Allistone JC. Resistance to trimethoprim-sulfamethoxazole in the treatment of Pneumocystis carinii pneumonia. Implication of folinic acid. Chest 1984 Jul;86(1):149-50.
2.Razavi B, Lund B, Allen BL, Schlesinger L. Failure of trimethoprim/sulfamethoxazole prophylaxis for Pneumocystis carinii pneumonia with concurrent leucovorin use. Infection 2002 Jan;30(1):41-2.
3.Bactrim Inj. (sulfamethoxazole and trimethoprim) US prescribing information. Mutual Pharmaceutical Company, Inc. March, 2017.
4.Safrin S, Lee BL, Sande MA. Adjunctive folinic acid with trimethoprim-sulfamethoxazole for Pneumocystis carinii pneumonia in AIDS patients is associated with an increased risk of therapeutic failure and death. J Infect Dis 1994 Oct;170(4):912-7.
5.Bygbjerg IC, Lund JT, Hording M. Effect of folic and folinic acid on cytopenia occurring during co-trimoxazole treatment of Pneumocystis carinii pneumonia. Scand J Infect Dis 1988;20(6):685-6.
6.Bozzette SA, Forthal D, Sattler FR, Kemper C, Richman DD, Tilles JG, Leedom J, McCutchan JA. The tolerance for zidovudine plus thrice weekly or daily trimethoprim-sulfamethoxazole with and without leucovorin for primary prophylaxis in advanced HIV disease. California Collaborative Treatment Group. Am J Med 1995 Feb;98(2):177-82.