trimetrexate (Neutrexin)

Tradename: Neutrexin. Indications: Pneumocystis carinii pneumonia (PCP) Dosage: - 45 mg/m2 IV QD over 90 minutes for 21 days Must be given with leucovorin: 1) 20 mg/mg IV every 6 hours over 5-10 minutes or 20 mg/m2 PO every 6 hours (round up to higher 25 mg increment) 2) continue leucovorin for 72 hours past final trimetrexate dose Powder for injection: 25 mg. Dosage adjustment for hematologic toxicity: neutrophils/uL platelets/uL trimetrexate leucovorin > 1000 > 75,000 45 mg/m2 QD 20 mg/m2 every 6 hours 750-1000 50-75,000 45 mg/m2 QD 40 mg/m2 every 6 hours 500-750 25-50,000 22 mg/m2 QD 40 mg/m2 every 6 hours < 500 < 25,000 hold* 40 mg/m2 every 6 hours * hold for 96 hours Pharmacokinetics: 1) extensively metabolized in the liver 2) elimination 1/2life is 15-17 hours Adverse effects: - not common (1-10%) - peripheral neuropathy, seizures, rash, neutropenia, thrombocytopenia, anemia, stomatitis, nausea/vomiting, hepatotoxicity, renal toxicity, fever, flu-like syndrome, hypersensitivity Drug interactions: 1) decreased effect of pneumococcal vaccine 2) increased toxicity (infectious rates) yellow fever vaccine

Related

leucovorin (Wellcovorin) Pneumocystis pneumonia (PCP)

Properties

MISC-INFO: elimination route LIVER 1/2life 15-17 HOURS pregnancy-category D

References

Kaiser Permanente Northern California Regional Drug Formulary, 1998