Tuesday, January 6, 2009

depressants- continued

Antianxiety drugs
" minors" : this term is used to distinguished from the " major tranquilizers"
compounds such as chlorpromazine( Thorazine) which is used to manage psychosis

The first minor tranquilizer is meprobamate( Miltown/ Equanil)
The most popular appeared in 1960s: benzodiazepines: 
  • chlordiazepoxide( Librium)
  • diazepam( Valium)
  • triazolam( Halcion)
  • alprazolam( Xanax)
  • lorazepam( Ativan)
  • temazepam( Restoril)
  • clonazepam( Klonopin)
compared with barbiturates, benzodiazepines are safere in overdose and somewhat less dangerous in combination with alcohol

Flunitrazepam(Rohypnol) is a remedy for insomnia and pre-anesthtic medication for patients undergoing surgery. It is more potent and lasts longer than Valium. Availvale in the black market under the name " roofies". Users used this to enhance the effect of other drugs

It is very difficult to wean of benzodiazepines, since withdrawal is unpleasant and dangerous


GHB( Gammahydroxybutyrate)

GHB is an endogenous downer made in small amount in the brain as a metabolite of the sedatiuve neurotransmitter GABA
Synthetic GHB stimulates the pituitary gland to release growth hormone, which can help convert fat to muscle.

A teaspoon of GHB dissolved in warm water and taken on an empty stomach can cause the effect akin to alcohol and methaqualone intoxication

GHB can cause nausea and marked incoordination along with " hypersomnolence": a kind of temporary stupor in which people can stop breathing for periods.

GHB increases rather than suppresses dreaming. in this aspect, it is different from other depressants.

General Anesthetics:
gases or volatile liquids administered by inhalation through a mask placed over the face or tubes in the throat

Like all depressants, anesthetics can killby shutting down the respiratory centre and other vital functions.

CHroroform is the oldest form, but it is toxic so it is no longer used

Ether/ Diethyl ether : is still used before surgery.  But it can be explosive from accidental sparks or flames..

Nitrous oxide only has a faint odor, non toxic and nonflammable. does not produce complete loss of consciousness . Often used by dentistry orminor surgery

Some people havetried to get nitrous oxide directly from pressurized tanks, whipping cream. But people may get frostbites of the nose and the mouths of they attemptto do it incorrectly. Asphyxiation by breathing straight from face mask( without any supply of oxygen) may causedeath.

Narcotics
narcotics are drugs that produce stupor( state of reduced sensitivity) by depressing brain function, but their depressant function is different from sedative-hypnotics or general anesthetics

The parent of all narcotics is opium, a dark gummy solid made from opium poppy. As the flower wither, the green pods, which contain many tiny seeds, begin to ripen and swell. If the pods are ripened fully, they turn brown and dry. While still unripe, the pods contain a milky juice that can becollected by letting it ooze from the knife cuts. When dried, this ooze is crude opium.

Many oral preparations of opium were made in the past. Two that survive into our own time are paregoric, a dilute tincture ofopium cimbined with camphor, and a deodorized tincture ofopium, formerly known as laudanum

Crude opium is very bitter and contains more than twenty different drugs, of which the most important is morphine.

In 1803, morphine is prepared as a soluble white soluble poweder that can be mixed with water for injection

Codeine( methylmorphine) is another natural constituent of opium. More active by mouth than other narcotics, is a weaker pain reliever than morphine and doctors frequently prescribe it to treat moderate pain.

Heroin( diacetyl morphine) is more potent than morphine: producing the same effect in smaller dose.

Drugs derived from morphine and other opium compounds are opiates. Demerol( purely synthetic). In general, all opiates produce the same effect, only differ in their potency.

these generally act on the brain and bowel. THese paralyze the bowel, so narcotics can be used to treat diarrhea. Prolonged use induces chronic constiapation.

Tolerance for addictive dose of sedatives-hypnotics develop faster than their lethal dose- making them more easily overdose- compared to that of narcotics. Heroin overdose death is more often due to poor control of the drug.
Intravenous heroin use is most addictive due to its high potency and short duration

oxycodone: a semisynthetic opiate: blended with aspirin as Percodan and with acetaminophen as Percocet
Oxycotin: a more potent and time released version ofoxucodone.

methadone is a form of heroin maintenance. It blocks the effect of heroin, so gives junkies little motivation to shoot heroin. Oral methadone is an addicting narcotic but gives little euphoria.

A new semisynthetic opiate is called  buprenorphine has beenused for heroin addiction. It blocks the high of heroin and can be given in higher doses without suppressing breathing.