Pseudoephedrine is a sympathomimetic drug. Pseudoephedrine acts as an adrenomimetic and inhibitor of monoamine transporters. Ephedra sinica, a species of ephedra (ma huang), contains ephedrine and pseudoephedrine. Ephedra has been found to stimulate the nervous system, increase airflow into the lungs and constrict blood vessels. In combination with caffeine, ephedra appears to cause weight loss. Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Pseudoephedrine is used to relieve nasal or sinus congestion caused by the common cold, sinusitis, and hay fever and other respiratory allergies.

Ephedrine (l-form) is an alkaloid, which was initially purified from Ephedra plant. The extract form Ephedra has been used in China for medicinal purposes for several thousand years. Ephedrine acts as an agonist at alpha- and beta-adrenergic receptors and indirectly causes the release of norepinephrine from sympathetic neurons. The drug crosses the blood brain barrier and stimulates the central nervous system. Ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine. FDA has approved ephedrine only for the treatment of clinically important hypotension occurring in the setting of anesthesia.

Benzphetamine is a sympathomimetic agent with properties similar to dextroamphetamine. It is used in the management of exogenous obesity as a short term (a few weeks) adjunct in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of 30 kg/m2 or higher who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone. Presumably, benzphetamine produces its effects through mechanisms similar to amphetamine via induces synaptic vesicular amine transporter, but precise mechanism of action of benzphetamine is not known.

Pseudoephedrine is a sympathomimetic drug. Pseudoephedrine acts as an adrenomimetic and inhibitor of monoamine transporters. Ephedra sinica, a species of ephedra (ma huang), contains ephedrine and pseudoephedrine. Ephedra has been found to stimulate the nervous system, increase airflow into the lungs and constrict blood vessels. In combination with caffeine, ephedra appears to cause weight loss. Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Pseudoephedrine is used to relieve nasal or sinus congestion caused by the common cold, sinusitis, and hay fever and other respiratory allergies.