Drug Abuse Of Cocaine and Other Psychostimulants
- Biomolecular mechanisms of action
- Clinical pharmacology
- Clinical manifestations
Cocaine, an alkaloid extracted from coca leaves, and other psychostimulants (e.g., amphetamine, methamphetamine) rapidly increase the concentration of several neurotransmitters in synaptic junctions and stimulate the sympathetic and central nervous systems. Topical cocaine is used in otolaryngologic procedures, and psychostimulants are used either for their stimulant effects or for their paradoxical calming effect in some patients with attention-deficit hyperactivity disorder.
[...] The route of administration determines the amount of cocaine absorbed and the rapidity of its uptake in the brain. Swallowed or snorted (intranasal) cocaine penetrates biologic membranes poorly and undergoes 70 to 80% hepatic transformation. Cocaine administered intravenously or smoked is absorbed. The onset of action varies according to the route of administration: oral, peak effect in 1 hour; intranasal to 5 minutes for onset with a peak effect in 30 to 60 minutes; intravenous, onset in 12 to 16 seconds, with 10 to 20 minutes' duration of effect; and smoked, onset in 6 to 8 seconds with 5 to 10 minutes' duration of effect. [...]
[...] Topical cocaine is used in otolaryngologic procedures, and psychostimulants are used either for their stimulant effects or for their paradoxical calming effect in some patients with attention-deficit hyperactivity disorder. History The earliest recorded use of cocaine in the form of ingested coca leaf occurred around 3000 BC. In 1860, cocaine was isolated and incorporated into tonics, teas, and wines. In the 1880s, an Atlanta druggist patented a product that contained two naturally occurring stimulants, cocaine and caffeine, which eventually became known as Coca-Cola. [...]
[...] Possible degeneration of dopaminergic terminals in the brains of cocaine addicts is suggested by positron emission tomographic studies in which the binding of cocaine to dopamine transporters in the basal ganglia and thalamus is decreased. Clinical Pharmacology Cocaine can be smoked, ingested orally, applied to mucous membranes, or injected intravenously. Cocaine hydrochloride, a water-soluble powder often mixed with adulterants, can be used by all routes except that it cannot be smoked because it decomposes when burned. Freebase or crack cocaine, a chemically altered form of cocaine, vaporizes before decomposition and can be smoked. [...]