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Methotrexate and trimethoprim-sulphamethoxazole: extremely serious and life-threatening combination

O M Al-Quteimat1, M A Al-Badaineh

  • 1Pharmaceutical Care Department, King Abdullah Medical City, Makkah, Saudi Arabia. systemman86@yahoo.com

Journal of Clinical Pharmacy and Therapeutics
|March 26, 2013
PubMed
Abstract

Insights

Combining methotrexate (MTX) with trimethoprim-sulfamethoxazole (TS) can cause severe toxicity, including fatal pancytopenia. This drug interaction necessitates avoiding the combination and updating therapeutic guidelines to ensure patient safety.

Area of Science:

  • Pharmacology
  • Drug Interactions
  • Clinical Toxicology

Background:

  • Methotrexate (MTX) is a widely used medication.
  • Trimethoprim-sulfamethoxazole (TS) is a common antibiotic.
  • Potential for drug interactions exists between MTX and TS.

Observation:

  • Literature review identified one systematic review, three studies, and 17 case reports.
  • Evidence indicates a significant drug interaction between MTX and TS.
  • This interaction elevates the risk of MTX toxicity, including severe pancytopenia.

Findings:

  • The combination of MTX and TS is associated with a high risk of severe adverse events.
  • Fatal cases of pancytopenia have been reported due to this interaction.
  • Current literature strongly supports avoiding this drug combination.

Implications:

  • Therapeutic recommendations are needed to prevent MTX toxicity from drug interactions.
  • Updating clinical guidelines for MTX therapy is crucial.
  • Increased awareness among healthcare professionals and patients is essential for safe MTX use.

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