Included in this class are amphetamines, methamphetamine (P), methylenedioxymethamphetamine (MDMA), 3,4-Methylenedioxyamphetamine (MDA), para-Methoxyamphetamine (PMA), 4‑methylmethcathinone (Mephedrone, 4-MMC), 3,4-methylenedioxy-N-methylcathinone (Methylone, bk-MDMA), methylenedioxypyrovalerone (MDPV).
Usual constituents of party pills/Herbal Highs are 1,3-dimethylamylamine (DMAA), butylone, benzylpiperazine (BZP) and 3-trifluoromethylphenylpiperazine (TFMPP).
Cardiovascular - hypertension, tachycardia, ventricular arrhythmias (usual cause of death).
Respiratory - hyperventilation, pulmonary oedema.
Renal - acute renal failure secondary to rhabdomyolysis.
Ocular - mydriasis.
Gastrointestinal - nausea, vomiting and anorexia.
Other - hyperthermia, hyperkalaemia, trismus, diaphoresis.
Toxic dose not well established as the potency and purity vary. Severe toxicity can be due to cerebral haemorrhage, cerebral oedema, hyponatraemia or toxic hyperthermia. Deaths have occurred after ingestion of a single tablet.
Treatment - mainly supportive care
Consider activated charcoal.
If mild toxicity, observe for 4 hours after resolution of symptoms.
Benzodiazepines for agitation and/or seizures.
For refractory seizures, use phenobarbital (phenytoin contraindicated).
ECG monitoring.
Refractory hypertension may require treatment with short acting agents, e.g. glyceryl trinitrate (GTN) or sodium nitroprusside (SNP) infusion titrated to response.
Hyperthermia - temperatures >38.5°C may herald multiorgan toxicity. Aggressive cooling is required.
Note: Beta blockers are contraindicated as they can lead to unopposed alpha adrenergic stimulation.