Pharmacology of Substance Abuse (pharm of recreational drugs) Flashcards
How do most CNS depressants work?
most augment activity at GABA A receptor complexes–> increasing Cl- influx–> hyperpolarization of the cell–> Inhibitory actions
What 2 major factors does alcohol absorption depend upon?
- Concentration of alcoholic beverages
2. Stomach: empty vs. full
What drug is used for aversion therapy to help treat chronic alcoholism?
Disulfiram–> inhibits aldehyde dehydrogenase, resulting toxicity form acetaldehyde–> leads to symptoms such as pulsating headache, nausea, hot, vomiting, chest pain, weakness, dizziness, etc…
Treatment(s) for methanol or ethylene glycol poisoning?
- Ethyl alcohol
2. An alcohol dehydrogenase inhibitor- Fomepizol
What is the main mechanism of the CNS stimulant drugs (methamphetamine, cocaine etc.)?
increase CNS catecholamine/dopamine activity
How does cocaine specifically work?
inhibits uptake of NE, DA and 5HT
How do amphetamines and the cathinone synthetic drugs work?
reverse the transporters for NE, DA and 5HT causing their release
What is the mechanism of caffeine?
antagonist at inhibitory adenosine receptors
What is the mechanism of nicotine?
activates nAChRs on VTA dopamine neurons leading to increased DA release in nucleus accumbens and prefrontal cortex
Which receptor do the hallucinogens target?
5HT
Which receptors do the opiates target?
opioid
Which receptors do cannabis work through?
cannabinoid
What is the more specific mechanism of action of LSD, mescaline and psilocybin?
- agonist at 5HT2A receptors on Raphe cell bodyleading to inhibition of Raphe Nuclei firing and increased sensory input
- partial dopamine agonist
- *all show cross tolerance with each other**
What are some of the side effects of LSD, mescaline and psilocybin?
- bad trips (anxiety attack, panic attack)
- flashbacks
- “street drug” lifestyle
- *no overdoses, birth defects, or chronic psychoses linked to LSD**
What is the more specific mechanism of PCP?
- antagonist of ion channel associated with NMDA
- agonist at mu-opioid receptor
What are some of the side effects of PCP?
- violent behavior
- coma
- seizures
- arrest
- inexplicable psychoses
- dissociation
- confusion
- ataxia
- marked nystagmus
What are the effects of LSD?
altered perceptions (from increased sensory input)
- mood changes
- loss of ego boundaries
- magical thinking
What are the chemical properties of THC (solubility, metabolism, tolerance)?
- highly lipid soluble
- metabolized by P450 with some induction
- tolerance from P450 metabolism
Where are CB1 and CB2 receptors located and what are their effects?
CB1-brain–>euphoria
CB2-periphery–>immune system
Which drugs are included in the miscellaneous class?
PCP and ketamine-NMDA antagonists
Club drugs-MDMA, GHB, Meth
Date rape drugs-– Flunitrazepam (rohypnol), ketamine and GHB
What are the 3 enzymes used in the metabolism of alcohol?
Alcohol dehydrogenase, acetaldehyde dehydrogenase and CYP2E1
What order kinetic is the metabolism of alcohol and what is the limiting factor?
zero order, limited by supply NAD+
The enzyme CYP2E1 is not always used in the metabolism of alcohol, so when is it used?
- at high levels or in chronic use
- can be induced by chronic exposure to alcohol
- *metabolizes many other drugs also!!**
What is “alcohol sensitivity”?
genetic variations in enzyme activity (common in asians)
What can amphetamines be prescribed for and what are some side effects?
- treat: narcolepsy and ADHD
- side effects: vasospasm leading to stroke/MI, arrythmia, and wieght loss
What might cocaine be used therapeutically for and what are some side effects?
- treat: topical anesthetic-it is vasoconstrictor and local anesthetic
- side effects: paranoia, and aggression
What is the mechanism of action of namifene and what is it used for?
- opioid receptor antagonist
- used to treat opiate overdose
What is anandamide?
endogenous canabinoid
What are dronabinol and nabilone and what are they used for?
- synthetic THC
- anti-emetic and anti-nausea
- *less psychoactive effects then marijuana**
What are some of the possible side effects of marijuana use?
- may impair reproductive function in adolescent
- heavy use may impair development of very young users
- possible respiratory damage due to tar
- vasodilation –> tachycardia
- dilation of conjunctival vessels
- bronchodilation
- decreased intraocular pressure
- hunger
