Stimulants

Includes amphetamines (amphetamine, methamphetamine, dexamphetamine), plus methylphenidate, ephedrine, cocaine, and some appetite suppressants (e.g. phentermine). Synthetic “designer” stimulants with amphetamine-like properties include MDMA (“ecstasy”), PMA, and MDPV. Sought-after effects: euphoria, self-confidence, increased sexual behaviour, increased concentration, appetite suppression.

Amphetamine and cocaine overdose/toxicity

Anxiety, insomnia, confusion, paranoid psychosis, tremor, seizures, tachypnoea, hyperthermia, rhabdomyolysis, hypertension, tachycardia, and arrhythmias. Stroke can cause lasting disability; death can result from cardiac arrest or hyperthermia.

Ecstasy (MDMA/PMA) overdose/toxicity

Rarely but potentially fatal. Presentation resembles amphetamine toxicity; hyperthermia and hyponatraemia are the most significant toxic effects — core temperature can exceed 42°C, with secondary complications (rhabdomyolysis, DIC, acute kidney injury, metabolic disturbance) likely at that point. Treatment is symptom-directed: temperature reduction, fluid/electrolyte correction, and managing secondary complications — this is a medical emergency requiring direct ED transfer.

Liver injury can occur shortly after MDMA use or as a delayed effect — most cases resolve spontaneously, but some progress to liver failure. Antidepressants (SSRIs, moclobemide) are sometimes combined with ecstasy to intensify its effect, with significant toxicity risk.

Withdrawal

Hypersomnia, hyperphagia, irritability, aggression, depression, craving. No medication has proven particularly effective for amphetamine withdrawal — benzodiazepines may help irritability, and antidepressants may help withdrawal-related depression.

Treatment of dependence

CBT is effective for cocaine dependence and shows promise for methamphetamine dependence. Cocaine dependence may respond to disulfiram. There is no approved pharmacotherapy to aid reduction or abstinence in methamphetamine use disorder. Contingency management combined with CBT or another psychosocial intervention has the best evidence base for methamphetamine use disorder.

For the cardiovascular complications of methamphetamine use (screen, manage, harm-reduce), see Methamphetamine-associated cardiovascular conditions.