pharm of substance abuse Flashcards
1
Q
alcohol
A
- small molecule that easily crosses all membranes
- rate of absorption depends on concentration and empty vs. full stomach
- distribution = total body water
- 100 mg/dl = 0.10%
- LD50 = 450-500 mg/dl –> BAC = 0.45-0.5
2
Q
metabolism of alcohol
A
- ADH –> acetaldehyde (toxic!) –> ALDH (these enzymes require NAD+)
- all NAD-dependent reactions in liver are diverted –> TCA and oxidation of fat are inhibited –> fatty liver
- P450 metabolism is minimal (but is induced at higher levels of alcohol and with chronic consumption)
- metabolism of other drugs inhibited acutely, but induced with chronic use (enhanced P450 metabolism)
- the supply of NAD+ is the limiting factor determining the rate of alcohol oxidation –> saturation/zero order kinetics
3
Q
methyl alcohol/ methanol
A
- ADH –> formaldehyde and formic acid –> acidosis, retinal damage (blindness)
- tx: ethly alcohol to tie up ADH and prevent formation of toxic metabolites
4
Q
ethylene glycol
A
- ADH —> oxalic acid –> acidosis, nephrotoxicity
- tx: ethanol to tie up ADH
- forms oxalate crystals –> damaging to kidney
5
Q
amphetamine
A
- indirect sympathomimetic: release of biogenic amines (DA potentiation is most important for CNS stimulation)
- Tx: narcolepsy and ADHD
- stimulant: wakefulness, alertness, elevation of mood (w/ rebound depression), increased concentration, physical performance but tremor, paranoia, irritability, anorexia
- elevated BP –> reflexive slowing of HR
- vasospasm –> cerebral/cardiac ischemia, arrhythmias (just like MDMA bc)
6
Q
cocaine
A
- block reuptake of DA, NE, 5HT (DA potentiation most important for CNS stimulation and pleasure-reward)
- tx: topical anesthetic and vasoconstrictor
- amphetamine-like CNS stimulation
- cardiovascular complications
- rapidly hydrolyzed by plasma cholinesterase (ester local anesthetic)
7
Q
caffeine
A
- methylxanthine
- competitive antagonist at adenosine receptor
- increased capacity for skeletal muscle work, vasodilation (except in brain), increase in contractility and HR, diuretic, relieve bronchoconstriction
8
Q
nicotine
A
- CNS stimulant
- ganglionic stimulant and depolarizing ganglionic blocker
9
Q
hallucinogens
A
- LSD, mescaline, psilocybin –> all have cross-tolerance
- ecstasy is too
- schedule I drug: high potential for abuse and no currently accepted medical use (illegal!)
- 5-HT2a receptor agonist –> decreased inhibitory activity of Raphe Nuclei –> disinhibtion of sensory input
- mydriasis, elevated HR and BP, hyperreflexia, tachypnea, increased muscle tone, N+V, perceptual distortions, bad trips, no OD!
10
Q
marijuana/THC
A
- highly lipid soluble
- cannabinoid receptors: CB1 and 2 are GPCR’s –> regulation of energy balance, lipid and glucose metabolism
- vasodilation with reflexive increase HR, dilation of conjunctival vessels, bronchodilation, decrease IOP
- TX: anti-emetic, appetite stimulant, analgesic for neuropathic pain, glaucoma, asthma, migraines, MS
11
Q
Phencyclidine (PCP)
A
- dissociative anesthetic
- NMDA antagonist, opiod agonist
- dissociation, confusion, ataxia, nystagmus, psychosis, violent behavior --> coma –> seizures –>arrest
- long half life (lipid soluble + active metabolites)
- unique in causing both violent and psychotic behavior
12
Q
ecstasy
A
- MDMA
- psychoactive substituted amphetamine
- hyperthermia and dehyrdation (with crazy dancing!)
- low doses= subjective state of well-being, enhanced insight, closeness to others
- high doses= hallucinogenic, HTN crisis –> intracerebral hemmorhage, cardiac arrhythmias
- may be a 5HT neurotoxin
13
Q
anandamide
A
endogenous cannabinoid; arachidonic acid derivative
14
Q
mescalin
A
- phenylethylamine derivative
- similar structure to catecholamines (NE, Epi, DA, amphetamines) –> endogenous hallucinogens??
15
Q
LSD and psilocybin
A
Indole alkyl amine derivatives (5HT)
psilocybin = mushrooms
*similar structure to NTMs –> endogenous hallucinogens??
