ephedrine

Drug that acts like adrenaline on the sympathetic nervous system (sympathomimetic). Once used to relieve bronchospasm in asthma, it has been superseded by safer, more specific drugs. It is contained in some cold remedies as a decongestant. Side effects include rapid heartbeat, tremor, dry mouth, and anxiety.

Ephedrine is an alkaloid, C10H15NO1, derived from Asian gymnosperms (genus Ephedra) or synthesized. It is sometimes misused, and excess leads to mental confusion and increased confidence in one's own capabilities as they actually decline.