http://www.unl.edu/tcweb/pharm/drugs/abuse/cocaine.html

Cocaine and Methamphetamine

Cocaine may be used by a physician as a local anesthetic (Mucosal-Local) to numb certain areas of the body prior to examination or surgical procedures

(USPDI, 1993). It is also used as a vasoconstrictor. When used as a recreational drug, cocaine acts as a central nervous system stimulant and serves as a

euphoriant and mood elevator. It is typically sniffed, snorted, chewed, smoked, or injected. The effects of the drug depend upon the the amount of the dose,

the method of ingestion, and the level of tolerance developed by the body. Low to average doses of cocaine produce feelings of intense giddiness, alertness and

energy, increase work production, reduce boredom and fatigue, temporarily elevate mood and suppress the appetite. After cocaine is eliminated from the

system, the body rebounds, resulting in a return of appetite, fatigue and depression. An amplification of the "fight or flight" reaction of the sympathetic nervous

system, cocaine use produces increased heart rate, higher blood pressure, pupil dilation, increased respiration, increased blood sugar levels, and increased

blood flow to the motor muscles (Julien, 1995). Cocaine abusers believe that the drug improves their cognitive, physical and sexual abilities. The individual

may exhibit increased self-consciousness and bragging behaviors. Sixteen to thirty-two milligrams of cocaine injected intravenously results in a brief state of

intense euphoria that attains its peak levels within 8 to 12 minutes after administration, deteriorating within 30 to 40 minutes. After peaking, the euphoric mood

appears to level off with the introduction of feelings of anxiety. The aftermath is characterized by anxiety, which may last for several hours. Crack, the rock

crystal form of cocaine, acts upon the body in a similar manner when smoked. Intranasal methods, such as snorting, are slower, and thus, less-favored routes

of administration for chronic abusers. Intranasal ingestion has an initial onset of 2 to 3 minutes, with the euphoria lasting approximately 30 to 45 minutes.

Those who are habitual snorters usually develop irritation of the nasal passages, chronic dripping, ulceration of the nasal mucous memebranes, congestion, and

eventually, a perforated nasal septum.

Cocaine tolerance has a rapid onset, usually developing after the first few administrations of the drug. The abuser tends to crave more of the cocaine, which has

highly reinforcing properties. Higher doses result in more intense rebounds and toxic symptoms in the aftermath, and thus intensify the desire for the cocaine.

Hypervigilance, extreme anxiety, paranoia and suspisiousness, insomnia, and fears of persecution are common symptoms of toxic paranoid psychosis

produced by habitual use of high levels of cocaine.