Very-High-Dose Methadone With Minimal Toxicity and Inadequate Pain Control in a Hospice Patient With Cancer

Abstract

A case is reported of a 48-year-old Caucasian male who was admitted to hospice care with metastatic cancer of the larynx. The patient required very high methadone doses and experienced little opioid toxicity. The pharmacodynamics and pharmacokinetics of methadone are discussed in the context of this patient experience.

Extreme doses of intravenous methadone for severe pain in two children with cancer

“…Methadone that only contains the R-enantiomer is available in Germany, but a racemic mixture is still used due to limited evidence of the clinic response of R-methadone. Methadone is metabolized in the liver to inactive metabolites mainly by the hepatic enzymes CYP3P4A and CYP2B6 [2,12]. Drugs such as phenytoin, carbamazepine, corticosteroids, and rifampin increase the metabolism while amitriptyline, erythromycin, ciprofloxacin, ketoconazole, and cimetidine reduce its metabolism [1,2,12].…”

“…Methadone is metabolized in the liver to inactive metabolites mainly by the hepatic enzymes CYP3P4A and CYP2B6 [2,12]. Drugs such as phenytoin, carbamazepine, corticosteroids, and rifampin increase the metabolism while amitriptyline, erythromycin, ciprofloxacin, ketoconazole, and cimetidine reduce its metabolism [1,2,12]. The gene status of our patients was unknown but both responded to low dose of methadone after weaning suggestion normal metabolism.…”