Trimetrexate (Systemic)

Brand Names : Neutrexin

Proper Use of This Medicine

When you take leucovorin :

• Leucovorin must be taken with trimetrexate to help prevent very serious, possibly life-threatening, unwanted side effects. Leucovorin should be taken during trimetrexate treatment and for 3 days after trimetrexate is stopped. It is very important to take this medicine exactly as your doctor told you. Failure to do this can result in very serious side effects.
• Take oral leucovorin exactly as directed by your doctor . Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. Also, do not stop taking this medicine without checking with your doctor first.
• Oral leucovorin works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses . If you need help in planning the best times to take your medicine, check with your health care professional.
• If you vomit shortly after taking an oral dose of leucovorin, check with your doctor. You will be told whether to take the dose again or to wait until the next scheduled dose.

Dosing - The doses of trimetrexate and of leucovorin will be different for different patients. Follow your doctor's orders or the directions on the label . The following information includes only the average doses of trimetrexate and leucovorin. If your doses are different, do not change them unless your doctor tells you to do so.

For trimetrexate
• For the treatment of Pneumocystis carinii pneumonia:
  • For injection dosage form:
    • Adults - 45 milligrams per square meter of body surface area (mg/m² ) injected into a vein once a day for twenty-one days. Your doctor will check your blood counts and may change your dose based on these counts. Your doctor may want to give you a dose you based on how much you weigh. Your dose will be determined by your doctor.
    • Children and teenagers - Use and dose must be determined by your doctor.

For leucovorin
• For the prevention of serious side effects of trimetrexate in the treatment of Pneumocystis carinii pneumonia:
  • For the oral or injection dosage forms:
    • Adults - 20 milligrams per square meter of body surface area (mg/m ² ) taken by mouth or injected into a vein every six hours for twenty-four days. Your doctor will check your blood counts and may change your dose based on these counts. Your doctor may want to give you a dose you based on how much you weigh. Your dose will be determined by your doctor.
    • Children and teenagers - Use and dose must be determined by your doctor.

Missed dose - If you miss a dose of leucovorin, take it as soon as possible. This will help to keep a constant amount of medicine in the blood. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage - To store leucovorin:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.