The sympathomimetic toxidrome is a combination of physical findings characteristic of overdose of certain classes of drugs, including cocaine and amphetamines. Other sources include naturally occurring versions of the khat plant (Catha edulis, which has been chewed for centuries due to its amphetamine-like effect), from which synthetic cathinones (known as "bath salts" in America and as "plant food" in Europe) are derived. Ingestion of tyramine-rich foods (eg, aged cheese, red wine, and other fermented products) in combination with certain medications that act as monoamine oxidase (MOA) inhibitors can also produce this effect. Signs of sympathomimetic toxicity are suggestive of overactivity of the sympathetic nervous system.

Sympathomimetic agents mimic the effects of catecholamines (eg, epinephrine, norepinephrine, dopamine), causing increased sympathetic activity in the nervous system. They are separated into direct sympathomimetics (eg, epinephrine, phenylephrine), which bind directly to an adrenergic receptor; indirect sympathomimetics (eg, amphetamine, tyramine), which enhance the activity of catecholamines; and mixed (eg, ephedrine), which have both direct and indirect properties. Direct sympathomimetics are further separated based on their selectivity for a receptor (eg, α1 receptor for phenylephrine) or lack of selectivity (eg, nonselective adrenergic receptor agents).

Related topic: Cocaine-related cardiomyopathy