The only source for all the world's cocaine is a South American shrub, the leaves of which contain about 0.5 - 1.0% of cocaine. Collecting the leaves, extracting the cocaine, smuggling it into foreign countries as cocaine hydrochloride or crack cocaine, and distributing it, constitutes a complex, dangerous and highly lucrative operation that impacts the lives of hundreds of millions of peoples. For extraordinary stories about the smuggling of cocaine into the United States, see my book, mentioned at the end of this site.The most important pharmacologic action of cocaine is central nervous system (CNS, brain and spinal cord) stimulation. A second important property is local anesthesia with accompanying vasoconstrictor action.
CNS STIMULATION: In doses of 25 - 100 mg (milligrams), cocaine produces effects described by Sigmund Freud 100 years ago. It produces exhilaration, euphoria, great capacity for work (mental and physical), without fatigue, increase in self-control, and elimination of the need for food or sleep. It makes the user feel masterful, competent and full of energy. These are pleasureful sensations that very strongly pressure the user to ingest the drug again and again. However, the user soon discovers that while cocaine may produce ecstasy, it never produces satisfaction.
One of the most insidious toxic effects of cocaine is a "kindling" effect on the brain in which ingesting cocaine over a period of time can sensitize the brain to subsequent doses. Users believe they are taking a safe dose when in reality their brain's threshold for seizure (and sudden death) has been greatly lowered. Cocaine can cause sudden cardiac death, heart attack, irregular heartbeat and heart muscle tissue damage. Used in pregnancy, cocaine can cause miscarriage, premature delivery or mental damage to the neonate.
The street cocaine known for scores of years is cocaine hydrochloride, a salt form more stable but more water soluble. "Crack" cocaine is exactly the same drug, but transformed (by the supplier or by the kitchen chemist) into the free base form. Free of the hydrochloride salt, the base can be easily heated in a pipe to a smoke (vapor) that can be inhaled, thus facilitating very rapid transfer to the brain. It is the acute, highly pleasureful brain rush that makes cocaine so esteemed by the abuser.
Space constraints here limit discussion of the vast literature on the pharmacology of cocaine, including its mechanism of action involving dopamine.However, you can read much more about cocaine in my book, "Drugs and the Human Body", Seventh Edition.
LOCAL ANESTHETIC ACTION. Not only is cocaine an excellent local anesthetic, it has its own built-in vasoconstrictor action, facts which make this drug especially valuable in surgery of highly vascular areas such as face and neck, and in intubatiions.
OTHER CNS STIMUL;ANTS.Other drugs that can excite the brain and spinal cord are the amphetamines (discussed above), caffeine, strychnine, nicotine, Ritalin, phenylpropanolamine (PPA), pseudoephedrine, and the many OTC diet aids, most of which supposedly function by exciting the brain.It must be remembered that all these drugs, including cocaine and the amphetamines, can also act to stimulate the heart, increase blood pressure, and diminish appetite, and that therefore they are potentially dangerous drugs.