Summary
It is well-established within the scientific literature that amphetamine can provide an analgesic (pain killing) effect in its own right, and enhance the analgesic effects of opiate painkillers (e.g. morphine, codeine).
Recent developments in the treatment of the terminally ill suggests amphetamines may have a role to play in the management of severe pain as an adjunctive therapy, by enhancing the effects of opiates. However, this role is limited in long-term use by the high degree of tolerance and dependence which frequently develops with prolonged stimulant use.
Opiates are likely to cause drowsiness, reduced alertness and impaired cognitive function - effects which are reduced or reversed by amphetamine. The risk of respiratory depression with high doses of opiates is also reduced with amphetamine, allowing larger doses pain-relief.
The analgesic role of stimulant drugs is thought to mimic the effects during stress, where pain (e.g. from an injury) is not experienced during crises such as armed combat or other potentially life-threatening events (such effects are even reported in sporting contests).
