Treatment of Amphetamine Use IV benzodiazepines IM or IV ketamine for acute agitation IV nitrates for hypertension unresponsive to benzodiazepines as needed Cooling for hyperthermia as needed Toxicity or overdose When a significant amount of amphetamines has recently been taken orally (eg, < 1 to 2 hours), activated charcoal may be given to limit absorption, although this intervention has not been shown to reduce morbidity or mortality.