Chapter 12 - Psychomotor Stimulants Flashcards
Source of cocaine
Alkaloid in leave of the shrub Erythroxylon coca native to South America. isolated in the 1850s, became popular by snorting or IV in the 1970s
Basic pharmacology of cocaine
extracted from coca leaves, converted to a HCL salt and crystallized. cocaine HCL is water-soluble and can be taken orally, intranasally, or IV. cocaine HCL can be transformed back into cocaine by 2 methods (freebasing and crack)
absorption rate of cocaine
rapid absorption with IV injection and smoking, slower w oral and nasal.
Mechanism of cocaine action
Blocks reuptake of DA, NE, and 5-HT by inhibiting transporters. DA reuptake inhibition most important
mild/moderate effects vs severe effects
mild/moderate - mood amplification, heightened energy, insomnia, restlessness, talkativeness, hyperactive ideation, increased sexual interest, mild anorexia, inflated self-esteem
severe - irritability, hostility, anxiety, fear, withdrawal, exhaustion, total insomnia, rambling, disjointed flight of ideas, decreased sexual interest, anorexia, violence, delusions of grandiosity
Why does cocaine have the potential to be abused?
The cocaine high - feelings of exhilaration, euphoria, well-being,
heightened energy, and self-confidence. powerful reinforcing properties
cocaine effects on the sympathetic NS
physiological effects include increased heart rate,
vasoconstriction, hypertension, hyperthermia
Psychological/behavioral symptoms can include agitation, mania,
paranoia, and a state of delirium
High doses can be fatal: seizures, heart failure, stroke, intracranial hemorrhage
Which pathways are involved in the behavioral effects?
Dopaminergic pathways from the midbrain (substantia nigra and VTA) to the striatum and NAcc
How do basal levels of DA or DAT affect a persons sensitivity to the drug?
Once a certain minimum level of DAT occupancy is attained the subject may experience a drug-induced high, higher base levels would cause this high to be reached faster
Which receptor subtype seems to moderate the effects of cocaine?
Studies using DA receptor knockout mice show that D1 receptors are required for locomoter-stimulating effects. D1 knockout mice don’t self-administer cocaine, suggesting a critical role for this receptor in reinforcement
What does chronic cocaine use cause?
diminished striatal dopaminergic activity, including down-regulation of neurotransmitter synthesis, release, and neurotransmitter transporter and receptor levels.
Cocaine acts in the nervous system by blocking _______ and voltage-gated _______ channels
monoamine transporters; sodium
Amphetamine, methamphetamine, and Ephedrine sources
Amphetamines - synthetic; structurally related to DA
Methamphetamine - synthesized from pseudoephedrine
Ephedrine - from the herb Ephedra; sold for weight loss but has dangerous side effects
Basic pharmacology of amphetamines
typically taken orally or IV or subcutaneous injection. long half lives, longer-lasting high from single dose than from single does of cocaine
mechanism of action of amphetamines
Catecholamine agonist stimulate DA and NE release and block reuptake
