Drugs of Abuse - Bloom Flashcards
How is drug abuse defined?
What types of drugs is it most applicable to?
“The use of a drug in a manner that deviates from the approved medical patterns within a society”
This is largely directed at psycho-affective medications.
Distinguish between some of the different aspects of drug tolerance (dispositional, pharmacodynamic, etc).
Dispositional tolerance results from pharcmacokinetic causes, eg Barbiturates inducing their own metabolism.
Pharmacodynamic tolerance mostly pertains to target organ sensitivity, eg Downregulation of target receptor.
Behavioral tolerance pertains to a reduced behavioral response, eg James Bond after 3 martinis (still smooth!)
Cross-tolerance occurs between drugs of the same class.
Contrast between physical and psychological drug dependence.
Physical drug dependence refers to physical symptoms brought about by drug withdrawal (not seen with all drugs).
Psychological dependence refers to compulsive feelings of need to take the drug (also applies to things like gambling, internet gaming)
How has DSM-5 restructured the classification of substance use and -induced disorders?
Both categories have been grouped together. Substance abuse and dependence have been equivocated as “use disorders”, while intoxication/withdrawal/induced illnesses have remained more or less the same.
What criteria are needed to classify a substance use disorder?
A problematic pattern of substance use within a 12mo period manifesting as 2+ symptoms of…
Increased amount or duration of doping
Persistent desire, failure to cut down use
Excessive time spent obtaining, using, or recovering
Cessation of social, occupational, or recreational activities
Continued use despite recurrent problems, use in hazardous settings
Tolerance or withdrawal symptoms (dependence not required for diagnosis!)
When connected to a drug reservoir that is activated by a lever, for which drugs will a rat incessantly push the lever?
Stimulants, opioids, and depressants. Not hallucinogens!
What is the most commonly used drug by high schoolers?
Is it more prevalent in boys or girls?
How does it compare to cigarettes?
Marijuana.
Boys (risky behavior, novelty, etc)
Has recently exceeded cigarette use!
Cannabis contains hundreds of cannabinoid compound. Which is the primary psychoactive agent?
How much can be found in cannabis, and how does this compare to a few decades ago?
Delta-9-tetrahydrocannabinol.
Anywhere from 2-10%, much more than in years past. Note that hashish or hash oil contains even more.
How do compounds like cannabidiol or cannabinol compare to THC?
They do not bind cannabinoid receptors as well, and so have much less psychogenic effect. May be metabolites of THC.
What role does the liver play in the metabolism of THC?
How is it excreted?
How long is it detectable for?
Liver activates THC by 11-hydroxylating it. It later inactivates it by metabolizing it to a 9-carboxyl compound.
In both urine and feces.
Up to 30 days, owing to its highly lipophilic nature.
How long-acting is THC?
How does the smoked formulation compare to the eaten?
1-6hrs
Smoked reaches brain faster and is much more potent than the ingested version. However, there are some side effects as noted later…
Describe the mechanism by which cannabis causes CNS effect.
Activation of mainly the CB1 receptor, found in the cerebellum, hippocampus, and basal ganglia. This is a Gi-coupled receptor.
CB2 receptor is found in peripheral tissue, may be useful for analgesia.
Name two endogenous cannabinoids.
How were they discovered?
2-Arachidonylglycerol (2-AG) and anandamide (arachidonylethanolamide).
After the receptor was discovered in the study of cannabis, endogenous compounds were theorized to exist. The same pattern lead to the discovery of endorphins!
What effect does THC have on mood, memory, and motor function?
THC causes euphoria & mellowing, but impairment of short-term memory and motor functions (#2 substance involved in motor vehicle collisions).
What are the effects of THC on the cardiovascular system?
The pulmonary system?
Tachycardia with orthostatic hypotension. Beware in angina!
Bronchodilation, but the smoked form is irritating and may cause bronchoconstriction, decreased alveolar macrophage activity, and decreased ciliary function.
How does THC affect reproductive function?
Is it effective as a contraceptive?
Lowers testosterone level and sperm counts. Decreases LHRH release (decreasing gonadal weight), as well as prolactin release (abnormal menstrual cycles).
God no.
What are some possible negative psychiatric effects of THC?
Anxiety, paranoia (avoid use in schizophrenics), “diffuse acute brain syndrome”, and amotivational syndrome (those who are often stoned, don’t do much. Causality is unclear though)
