Amphetamines are a class of pharmaceuticals that result in an increase in metabolic functions, resulting in a higher heart rate and respiration rate.
Amphetamines were once commonly used as diet pills (as one of their side effects is the reduction of hunger) and aids for drowsiness (as they increase alertness). However, they're habit forming and stopping use of the drug results in severe symptoms of withdrawal. In addition, severe insomnia is a common side effect of even moderate use. As such, they are rarely used for such purposes by responsible physicians, although they're often abused by patients.
Amphetamines are still used to treat Attention Deficit Hyperactivity Disorder, traumatic brain injury, narcolepsy, and chronic fatigue.
In Resignation, House dosed Wilson with amphetamines to determine if he was hiding a medical condition from him. In retaliation, Wilson dosed House with antidepressants.