Trimetrexate
Definition
Trimetrexate (Neutrexin) is a drug that was first used to treat bacterial infections, and is now being investigated as a treatment for several different cancers.
Purpose
Trimetrexate is most commonly used to treat pneumonia in patients with acquired immunodeficiency syndrome (AIDS). However, it was recently discovered that the drug was able to kill a variety of different cancer cells. As a result, trimetrexate is now considered to be an investigational drug for cancer treatment.
Ongoing clinical trials are using trimetrexate to treat a number of cancers including advanced colon and rectal cancers, advanced pancreatic cancer, and advanced squamous cell cancers of the head and neck. Results from many trials are still preliminary, but trimetrexate appears to be most promising as a treatment for advanced colon and rectal cancers.
Description
Trimetrexate glucoronate works by stopping cells from using folic acid (vitamin B9). As a result, cells cannot make essential components they need to survive, and they die. Because trimetrexate is toxic to both cancer cells and healthy cells, it is always used in combination with leucovorin (Wellcovorin, citrovorum factor). Leucovorin is a drug that protects healthy cells from the harmful effects of certain types of chemotherapy.
Trimetrexate can also enhance the anti-cancer effect of another chemotherapy drug called fluorouracil (Adrusil, 5-FU). Fluorouracil is frequently used to treat patients with colon and rectal cancers.
Recommended dosage
In clinical trials, patients with colon and rectal cancers were given trimetrexate, fluorouracil and leucovorin for 8-week cycles. A cycle consisted of six weeks of treatment followed by two weeks rest with no treatment. Patients received trimetrexate intravenously, with the dose depending on their weight. Twenty-four hours after trimetrexate treatment, patients received intravenous fluorouracil and leucovorin treatment. Some patients also took oral leucovorin every six hours for several days after their intravenous chemotherapy.
Patients with squamous cell cancer of the head and neck received trimetrexate in combination with cisplatin (Platinol), leucovorin and fluorouracil in a 21-day cycle. These patients also received surgery or radiation therapy. Pancreatic cancer patients received 8-week cycles of trimetrexate, fluorouracil and leucovorin, similar to that given to patients with colon cancer.
