Neutrexin Dosage
Generic name: trimetrexate glucuronate
Dosage form: for Injection
Medically reviewed by Drugs.com. Last updated on May 1, 2020.
Caution: Neutrexin (trimetrexate glucuronate for injection) must be administered with concurrent leucovorin (leucovorin protection) to avoid potentially serious or life-threatening toxicities. Leucovorin therapy must extend for 72 hours past the last dose of Neutrexin.
Neutrexin (trimetrexate glucuronate for injection) is administered at a dose of 45 mg/m2 once daily by intravenous infusion over 60 minutes. Leucovorin must be administered daily during treatment with Neutrexin and for 72 hours past the last dose of Neutrexin. Leucovorin may be administered intravenously at a dose of 20 mg/m2 over 5 to 10 minutes every 6 hours for a total daily dose of 80 mg/m2, or orally as 4 doses of 20 mg/m2 spaced equally throughout the day. The oral dose should be rounded up to the next higher 25 mg increment. The recommended course of therapy is 21 days of Neutrexin and 24 days of leucovorin.
Neutrexin and leucovorin may alternatively be dosed on a mg/kg basis, depending on the patient’s body weight, using the conversion factors shown in the table below:
| Body Weight (kg) | Neutrexin Dose (mg/kg/day) | Leucovorin Dose (mg/kg/qid) |
| <50 | 1.5 | 0.6 |
| 50-80 | 1.2 | 0.5 |
| >80 | 1.0 | 0.5 |
Dosage Modifications
Hematologic toxicity: Neutrexin (trimetrexate glucuronate for injection) and leucovorin doses should be modified based on the worst hematologic toxicity according to the following table. If leucovorin is given orally, doses should be rounded up to the next higher 25 mg increment.
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| Recommended Dosages of | ||||
| Toxicity Grade |
Neutrophils (Polys and Bands) |
Platelets | Neutrexin | Leucovorin |
| 1 | >1000/mm3 | >75,000/mm3 | 45 mg/m2 once daily | 20 mg/m2 every 6 hours |
| 2 | 750-1000/mm3 | 50,000-75,000/mm3 | 45 mg/m2 once daily | 40 mg/m2 every 6 hours |
| 3 | 500-749/mm3 | 25,000-49,999/mm3 | 22 mg/m2 once daily | 40 mg/m2 every 6 hours |
| 4 | <500/mm3 | <25,000/mm3 |
Day 1-9 Discontinue Day 10-21 Interrupt up to 96 hours* |
40 mg/m2 every 6 hours |
Hepatic toxicity: Transient elevations of transaminases and alkaline phosphatase have been observed in patients treated with Neutrexin. Interruption of treatment is advisable if transaminase levels or alkaline phosphatase levels increase to >5 times the upper limit of normal range.
Renal toxicity: Interruption of Neutrexin is advisable if serum creatinine levels increase to > 2.5 mg/dL and the elevation is considered to be secondary to Neutrexin.
Other toxicities: Interruption of treatment is advisable in patients who experience severe mucosal toxicity that interferes with oral intake. Treatment should be discontinued for fever (oral temperature ≥ 105°F/40.5°C) that cannot be controlled with antipyretics.
Leucovorin therapy must extend for 72 hours past the last dose of Neutrexin.
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
