Dextro propoxyphene hydrochloride (Darvon)* is a synthetic analgesic drug which is related pharmacologically to codeine. It has been in use for approximately three years. The drug is supplied in 32 mg. and 65 mg. capsules and is also combined (32 mg.) with acetophenetidin (162 mg.), acetylsalicylic acid (227 mg.), and caffeine (32 mg.) in a compound (Darvon Compound). The usual single adult dose is 32 mg. or 65 mg. In mice the oral LD50 of dextro propoxyphene is 273 mg/kg., and in rats the value is 185 mg/kg.1 Animals given massive toxic doses develop respiratory depression. Lethal amounts produce respiratory arrest, which is the cause of death.
Twelve cases of accidental ingestion and acute overdosage involving dextro propoxyphene have been reported by various poison control centers to the National Clearing-house for Poison Control Centers. Ingestion of larger than therapeutic amounts of the drug or the compound was followed by
CANN HM, VERHULST HL. Convulsions as a Manifestation of Acute Dextro Propoxyphene Intoxication. AMA Am J Dis Child. 1960;99(3):380-382. doi:10.1001/archpedi.1960.02070030382013