Methadone has unique characteristics that make it an attractive agent for the treatment of chronic pain and opioid drug dependence. However, methadone prescription requires more clinical experience and close monitoring of patients to avoid its undesirable side effects. Recently, levorphanol has emerged as "a forgotten opioid" with a similar profile as methadone. Levorphanol has no impact on QTc prolongation and considerably less drug-drug interactions as compared to methadone. Lack of commercial availability, providers' unfamiliarity, and limited clinical data on its effectiveness remain practical issues. The objective of this article is to review and compare the safety considerations for methadone and levorphanol use.
Keywords: Levorphanol; N-methyl-D-aspartate receptors (NMDA receptors); methadone; opioids; safety.