AN OVERVIEW OF HALLUCINOGENIC DRUGS

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I had recently been asked what harm, if any, is posed by the use of hallucinogenic drugs.  The answer is complicated because there are many types of these drugs and the degree of harm varies depending on the type.

The first family of drugs that I will discuss includes the anesthetics, Phencyclidine (PCP) and ketamine.  These medications work by affecting a certain type of receptor in the brain called NMDA glutamate receptor(which also plays a role in how alcohol affects the brain).  This stops certain nerves from firing and depresses certain brain activities.  In addition to these drug's hallucinatory effects, they cause depression and psychosis.  Short-term use with high dosages can cause coma, seizures, stroke and death.

Their use is associated with tolerance (the same amount of drug becomes less effective with repeated use) and a withdrawal syndrome characterized by depression, fatigue, increased appetite and craving for the drug.

The use of these drugs are pleasurable and animals will seek out the drug if it is taken away.  When animals are taken off high doses, they exhibit irritability, tremors, gooseflesh and other behavioral anomalies that resolve 48 hours after the last drug use.  

A syndrome of agitation occurs with PCP abuse.  It can be associated with relative insensitivity to pain; patients can hurt themselves and not be aware of an injury.  This is not from acute intoxication but is usually seen in early withdrawal. 

Long-term side effects of these drugs include prolonged depression and nerve damage.  While I cannot show any specific studies on the subject, I have always felt there was impairment in the higher intellectual functioning in many chronic PCP users.  This was true long after they had last used the drug.

In 2005, Campral became available for the treatment of alcohol problems.  Its mechanism of action suggests that it might be useful in people who have abused these drugs.  However, at the present time, there is no known treatment for withdrawal.

The second group of hallucinogens include LSD, psilocybin and mescaline as well as other similar drugs (DMA, DOM, DMT) These drugs are interesting in that they are among the few drugs, abused by humans, that animals do not seek out. These drugs do not stimulate dopamine and therefore they do not cause euphoria. These drugs work by mimicking a neurotransmitter called Seratonin. The hallucinatory effects usually resolve in 12 hours with psilocybin or mescaline, but have lasted up to three days with LSD.  During acute intoxication, blood pressure is elevated with a fast heartbeat, tremulousness, fever and poor coordination. Tolerance develops quickly so that after 3-4 days, there is far less of a clinical effect.  That is the reason that most users will use the drug intermittently.  There is no withdrawal syndrome.

With chronic LSD use, patients have reported flashback phenomena.  These are episodes of perceptual changes that occur long after the last use of the drug.  This phenomenon can be seen to a lesser extent with PCP and ecstasy.  It is a short-lived episode when aspects of the original drug experience are unexpectedly re-experienced.  Episodes can be triggered by stress, other drug use and in situations that are similar to the original drug experience.  It has been associated with depression, panic disorder and suicide attempts.

The last drug is MDMA, which is also known as Ecstasy.  This drug works similar to LSD in some ways.  However, it  also seems to produce a great deal of euphoria.  It has  other clinical effects similar to amphetamines.  Tolerance is seen but there is no physical withdrawal syndrome.   

The use of Ecstasy is not without risk.  In fact, this may be the most toxic drug that is abused.  We often hear how drugs kill brain cells.  While many drugs may cause nerves to dysfunction, they will not directly kill a nerve. Cocaine will may induce harm through altered blood flow and others though poor lifestyle.  Ecstasy is directly toxic.  In laboratory settings, a single molecule of Ecstasy has permanently knocked out Seratonin producing cells.  This will result in prolonged or permanent imbalances in Seratonin that can cause depression

Short-term use has also been associated with very high fevers, sweating, high blood pressure, irregular heart rhythms that can be life threatening, seizures, kidney problems and muscle breakdown.  It also associated with muscle spasms around the mouth.  Long-term effects are anxiety, agitation, flashbacks and nerve damage.

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S. Wasser

July 31, 1997