Sedatives, tranquilizers, muscle relaxants, antidepressants, and other central nervous system (
CNS) depressants may have additive
CNS- and/or respiratory-depressant effects with propoxyphene. Misuse of propoxyphene, either alone or in combination with other CNS depressants, has been a major cause of drug-related deaths, particularly in patients with a history of emotional disturbances, suicidal ideation, or alcohol and drug abuse.