As a powerful stimulant, methamphetamine, even in small doses, can increase wakefulness and physical activity and decrease appetite. Methamphetamine can also cause a variety of cardiovascular problems, including rapid heart rate, irregular heartbeat, and increased blood pressure. Hyperthermia (elevated body temperature) and convulsions may occur with methamphetamine overdose, and if not treated immediately, can result in death.37,38
The exact mechanisms whereby drugs like methamphetamine produce euphoria (the pleasurable high) are still poorly understood. But along with euphoria, methamphetamine use releases very high levels of the neurotransmitter dopamine in the reward circuit, which "teaches" the brain to repeat the pleasurable activity of taking the drug. Dopamine is involved in motivation and motor function and its release in the reward circuit is a defining feature of addictive drugs. The elevated release of dopamine produced by methamphetamine is also thought to contribute to the drug's deleterious effects on nerve terminals in the brain.
Short-term effects may include:
- increased attention and decreased fatigue
- increased activity and wakefulness
- decreased appetite
- euphoria and rush
- increased respiration
- rapid/irregular heartbeat
- hyperthermia