Cocaine

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Cocaine use is a very difficult problem.  Obtaining help to stop using cocaine can also be difficult.  This is because the withdrawal syndrome from cocaine is not well understood and hard to document.  Increasingly, the insurance companies are ignoring the need for treatment of cocaine withdrawal.

Cocaine works by directly increasing the dopamine levels in the nucleus accumbens or pleasure center of the brain (see Why We Use Drugs).  Normally, when a nerve releases dopamine into the synapse (which is the space between the nerves), it gathers the dopamine up again after a few milliseconds and then reuses it over and over.  Cocaine interferes with the process of regathering of the dopamine.  The concentration of dopamine in the synapse sharply increases which causes over stimulation of the receptors.  This results in an intense rush of pleasure.  That is why the drug is so highly addictive.  

During use, many parts of the brain become over stimulated and overactive.  This causes decreased appetite, inability to sleep, anxiety and tremors and possibly even seizures.  Dopamine levels are also affected in other areas of the brain.  It has long been appreciated that schizophrenia is caused by excessive dopamine in some areas of the forebrain.  It is no wonder that cocaine use can cause psychosis and hallucination and severely impair judgment.

The body has enzymes in the synapse whose job it is to break down dopamine.  When the dopamine is in the nerve cell, it is protected from theses enzymes.  However, when the dopamine in the synapse, the enzyme is able to break it down.  Since cocaine use causes dopamine to remain in the synapse, dopamine is metabolized more quickly.  After a while, less dopamine is available and the pleasure from using the drug becomes less.  The abuser may try to increase the amount of cocaine they use but, eventually, even that strategy fails. 

Then there is the cocaine crash.  This is caused by a few factors.  One reason is that there is now a lack of dopamine in the brain; this causes an “anti-pleasure” affect or depression.    Also, the lack of stimulation in other parts of the brain causes excessive fatigue.  The lingering effects the drug has on higher thought processes along with depression and fatigue result in an inability to think clearly and exercise good judgment.  This process often takes 3-4 days to recover from. 

In addition to the crash, many users experience severe cocaine cravings.  This ranges from excessive thoughts about the drug to severe hunger for the drug.  This severe hunger is often associated with physical symptoms that vary patient by patient.  Many scientists believe that the craving for the cocaine is caused by the relative lack of dopamine in the nucleus accumbens.  It is unclear how long this lack of dopamine lasts but it probably plays a role in the cravings that occur during the first few days.

The cocaine abuser often goes from intoxication to crash and back to drug use.  The depression, fatigue, cravings and inability to think straight often interfere with any ability to break the cycle.  Even after the first few days, cravings occur for the drug.  The mechanism underlying these later cravings is complex and not well understood but may also be partially caused by an alteration of dopamine metabolism in the nucleus accumbens


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