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Trimetrexate Dosage

Applies to the following strengths: 25 mg; 200 mg

Usual Adult Dose for Pneumocystis Pneumonia

45 mg/m2 IV over 60 to 90 minutes once a day for 21 days.

Trimetrexate must be given with concurrent leucovorin to avoid potentially serious or life-threatening toxicities. Leucovorin (20 mg/m2 IV or orally every 6 hours) must be given daily during trimetrexate treatment and for 72 hours past the last trimetrexate dose.

Renal Dose Adjustments

Treatment interruption is advisable if serum creatinine levels increase to > 2.5 mg/dL and the elevation is considered to be secondary to trimetrexate.

Liver Dose Adjustments

Treatment interruption is advisable if transaminase or alkaline phosphatase levels increase to > 5 times the upper limit of normal range.

Dose Adjustments

Neutrophils 750 to 1000/mm3 or platelets 50,000 to 75,000/mm3: The usual dose of trimetrexate is used. The leucovorin dose is increased to 40 mg/m2 every 6 hours.

Neutrophils 500 to 749/mm3 or platelets 25,000 to 49,999/mm3: Trimetrexate 22 mg/m2 once daily and leucovorin 40 mg/m2 every 6 hours.

Neutrophils less than 500/mm3 or platelets less than 25,000/mm3: Trimetrexate is discontinued if on days 1 through 9 of therapy. If past day 9 of therapy, trimetrexate may be discontinued for up to 96 hours. If the neutrophils recover to > 500/mm3 and platelets to > 25,000/mm3, therapy may be reinstituted per above guidelines. Leucovorin dose is 40 mg/m2 every 6 hours.


Interruption of treatment is advisable if severe mucosal toxicity that interferes with oral intake occurs. Discontinue therapy for fever (>40.5° C) that cannot be controlled by antipyretics. Leucovorin therapy must be extended 72 hours following the last dose of trimetrexate.

Safety and efficacy have not been established in children younger than 18 years.


Data not available

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.