A drug that reduces the effects of morphine and similar narcotic drugs and is used to stimulate breathing and restore consciousness after an overdose of these drugs. It is administered by injection and, given alone, may depress breathing and cause drowsiness or restlessness.
A drug which reduces or abolishes most of the actions of morphine and similarly acting narcotics, such as pethidine hydrochloride. It was used as an antidote in the treatment of over-dosage with these drugs but has now been superseded by naloxone.