Amiphenazoleis a respiratory stimulant traditionally used as an antidote for barbiturate or opiate overdose, usually in combination with bemegride, as well as poisoning from other sedative drugs and treatment of respiratory failure from other causes. It was considered particularly useful as it could counteract the sedation and respiratory depression produced by morphine but with less effect on analgesia. It is still rarely used in medicine in some countries, although it has largely been replaced by more effective respiratory stimulants such as doxapram and specific opioid antagonists such as naloxone. The hot-plate method has been used on mice to investigate the effect of amiphenazole on the analgesic activity of morphine. The phenomenon has been observed with oral, intraperitoneal and subcutaneous routes of administration.