- Cytochrome P450 enzyme substrate: CYP2E1
- Action to be taken: No action needed
- Rationale: In humans, dalfampridine is eliminated predominantly unchanged by the kidneys. No clinically significant drug interaction was identified. n vitro studies with human liver microsomes indicate that CYP2E1 was the major enzyme responsible for the 3 -hydroxylation of dalfampridine. In vitro data with human liver microsomes showed that dalfampridine was not a direct or time - dependent inhibitor of CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, or CYP 3A4/5. Dalfampridine is not likely to affect the pharmacokinetics of drugs that are substrates of these enzymes. In vitro studies show that cannabis does not interact with CYP2E1 enzyme. Therefore based on available data, cannabis is not expected to interact with dalfampiridine.
- Watanabe K, Yamaori S, Funahashi T, et al. Cytochrome P450 enzymes involved in the metabolism of tetrahydrocannabinols and cannabinol by human hepatic microsomes. Life Sci. 2007;80:1415-1419.
- Stout SM, Cimino NM. Exogenous cannabinoids as substrates, inhibitors, and inducers of human drug metabolizing enzymes: a systematic review. Drug Metab Rev. 2014;46:86-95.
- Ampyra (dalfampiridine) package insert. Acorda Therapeutics, Inc.Ardsley, NY 2016