Sympathomimetics are a class of
drugs whose effects mimic those of a stimulated
sympathetic nervous system. As such they increase cardiac
output, dilate bronchioles, and usually produce constriction
of blood vessels. Sympathomimetics include the naturally
occurring substances such as adrenaline (epinephrine),
noradrenaline (norepinephrine), dopamine, ephedrine, and
cocaine, as well as the synthetic drugs pseudoephedrine,
phenylephrine, phenylpropanolamine,
amphetamine and
methamphetamine, among others.
In medicine, certain
sympathomimetics are commonly prescribed in cardiac
emergencies including shock, asthma and anaphylaxis, in some
cases for weight loss, and in cold remedies, where they
shrink swollen membranes in the upper respiratory tract.
In recent years,
phenylpropanolamine has been removed from over-the-counter
cold formulations after it was implicated in causing an
increased risk of hemorrhagic stroke.
See also