THE EFFECTIVENESS AND TOXICITY OF METHADON, A NEW ANALGESIC AGENT

Abstract

150 hospitalized and 30 ambulatory patients, from 19 to 87 years of age, were treated with methadon for the relief of pain due to either medical or surgical conditions, or both. The dosage ranged from 2.5 to 20 mg. in a single dose or in repeated doses several times daily. Following the oral admn. of 2.5-5 mg. of methadon,complete or moderate relief was obtained in 40% of the cases. Methadon, given parenterally, was effective, regardless of the dose, in 76% of the cases. Ten mg. parenteral doses produced good analgesia in 88% of the patients. It was estimated that 10 mg. methadon was equivalent to 10 mg. of morphine. Toxic manifestations, such as nausea and vomiting, anorexia, dizziness, and weakness occurred twice as frequently after the oral, as after the parenteral admn. of methadon. The incidence of mental confusion and toxic psychoses for the entire group was about 5%. These complications were most common in those who received methadon orally for long periods. In 30 ambulatory patients suffering from arthritic diseases, who received the drug in 2.5 mg. doses every 4 hrs. for prolonged periods, complete control of pain occurred in 6, and an additional 7 obtained moderate relief. There was an 80% incidence of toxicity in this ambulatory group. The toxicity was severe in 13 of the 24 toxic cases. Increasing the dose caused a disproportionately greater increase of toxicity.