For example, substances like alcohol and benzodiazepines can involve severe physical withdrawal symptoms while cocaine results in mostly psychological symptoms. Physiological changes caused by cocaine withdrawal include vivid and unpleasant dreams, insomnia, hypersomnia, anger, increased appetite, weight gain, psychomotor retardation, agitation, depression, and anxiety. According to a study done by Gawin and Kleber in 1986, there are three phases in the withdrawal process. They observed the behavior of 30 cocaine-dependent individuals. Phase one, the crash, is characterized by acute dysphoria, irritability and anxiety, increased desire for sleep, exhaustion, increased appetite, decreased craving to use. Phase two, withdrawal, is characterized by increasing craving to use, poor concentration, some irritability and some lethargy, which persisted for up to 10 weeks. Lastly, phase three is characterized by the intermittent craving to use in the context of external cues. Cocaine and its metabolites are eliminated from the body by 3 days. There are not any FDA-approved medications that specifically help treat cocaine withdrawal, however, there are some useful medications that could possibly help individuals overcome their addiction. One example is propranolol. Propranolol is a beta blocker that has been approved to treat hypertension, angina, anxiety, and other related psychological problems. Buprenorphine and naltrexone are two substances that act as an effective treatment in the earlier stages of withdrawal. Pathophysiology
Cocaine pharmacodynamics involve multiple complex mechanisms. Although it has a short half-life (~ 1 hour), cocaine metabolites, which rise in concentrations several hours after cocaine ingestion, persist in circulation for up to 24 hours, and may cause delayed or recurrent coronary vasoconstriction.
This drug binds and blocks monoamine (dopamine, epinephrine, norepinephrine, and serotonin) re-uptake transporters with equal affinity. Monoamines accumulate in the synaptic cleft resulting in enhanced and prolonged sympathetic effects. Cocaines acute effect in the central nervous system is to raise the amount of dopamine and serotonin in the nucleus accumbens (the pleasure center in the brain). When this effect ceases due to metabolism of cocaine, depletion of associated neurotransmitters, and receptor down-regulation (tachyphylaxis), the cocaine user may experience dysphoria, or a "crash" after the initial high. The principal actions of cocaine on the cardiovascular system are from alpha- and beta-1-adrenoceptor stimulation resulting in increased heart rate, systemic arterial pressure, and myocardial contractility, which are major determinants of myocardial oxygen demand. Cocaine and its metabolites may cause arterial vasoconstriction hours after use. Epicardial coronary arteries are especially vulnerable to these effects, leading to decreased myocardial oxygen supply. Cocaine-induced platelet activation and thrombus formation is another deleterious effect, caused by alpha-adrenergic- and adenosine diphosphate-mediated increase in platelet aggregation. Plasminogen activator inhibitor is also increased following cocaine use, thereby promoting thrombosis. Cocaine acts like a class I antiarrhythmic agent by blocking sodium and potassium channels, in a similar way of local anesthetics such as lidocaine, and interferes with action potential propagation. This Vaughn-Williams class IC effect increases the risk of conduction disturbance and tachyarrhythmias. Adding to its complex toxicity, cocaine targets muscarinic acetylcholine, N-methyl-D-aspartate (NMDA), sigma, and kappa-opioid receptors. Management
There is no specific antidote for cocaine.