High-dose methotrexate: a clinical and pharmacokinetic evaluation. Treatment of advanced squamous cell carcinoma of the head and neck using a prospective mathematical model and pharmacokinetic surveillance.

Some of 66 patients with head and neck tumors were treated with high-dose methotrexate monochemotherapy. The use of a prospective mathematical model with pharmacokinetic surveillance proved to be reliable, practical, and useful. By this means chemotherapy could be individualized, with a resultant marked reduction in the frequency and severity of toxicity. The onset of clinical toxic manifestations was significantly correlated with a poor therapeutic response and poor prognosis. The patients were classified in to three groups according to poor, intermediate, and good pharmacokinetic parameters calculated after an intravenous identification dose of methotrexate. These group allocations had a very high prognostic value with regard to toxicity, and especially to the quality of therapeutic response to high-dose methotrexate. They are suggested as useful guidelines in the prescription of high-dose methotrexate chemotherapy.