Pharmacology of Drug Abuse Flashcards
what are the main classes of drugs used for drug abuse?
opioids, CNS depressants, anxiolytics and hypnotics, psychomotor stimulants, psychotomimetic agents
what are the opioids?
morphine, diamorphine, methadone, oxycodone
what are the CNS depressants?
alcohol, barbiturates, general anaesthetics, solvents
what are the anxiolytics and hypnotics?
benzodiazepines and GHB
what are the psychomotor stimulants?
cocaine, amphetamine, MDMA, nicotine
what are the psychotomimetic agents?
LDS, mescaline and cannabis
how do adaptive changes occur such as tolerance?
with chronic exposure
what is the definition of addiction?
relapsing drug use despite negative consequences
what is the reward pathway?
dopaminergic pathway from the ventral tegmental area (VTA) to the nucleus accumbent and prefrontal cortex
how do drugs effect the reward pathway?
drugs of dependance increase the release of dopamine in the nucleus accumbens or prefrontal cortex
what are opioids?
agonists at the mu-receptors in the central and peripheral NS, also act on other opioid receptor subtypes
what blocks the effects of opioids?
naloxone which is a specific antagonist
what are some of the central effects of morphine?
analgesia, sedation, euphoria, miosis, nausea and vomiting
what are the peripheral effects of morphine?
constipation, biliary spasm, constriction of oddi sphincter, histamine release
what are the adverse reactions of opioids?
dilation of blood vessels, drowsiness, pupil constriction, slurred speech, nausea, sexual dysfunction, constipation
on what receptors does ketamine act upon and how?
antagonist at NDMA receptors
what are NDMA receptors?
N-methyl D-aspartate receptor
what kind of receptor is an NDMA receptor?
ion channel linked glutamate receptor
what is ketamine bladder?
chronic usage causes bladder removal
in what ways can ketamine cause bladder removal?
disorder of urine/tissue interface, triggering of inflammatory response, metabolites damage microvasculature, autoimmune response, contaminants
what makes the NDMA receptor specific?
N-methyl-D-aspartate binds selectively to it and not other glutamate receptors
what are barbiturates?
synthetic drugs that act upon CNS depressants
what is the therapeutic window like of barbituates?
narrow window
what have barbiturates been used for?
sedative or hypnotics, treatment of epilepsy and shorter acting molecules used in anaesthesia
what makes barbiturates different to benzodiazepines?
similar mechanisms yet bind to different site on the receptor
what receptors does alcohol effect?
GABAa receptors, Kir3 channels, adenosine uptake, glycine receptors, NDMA receptors, 5-HT3 receptors, presynaptic Ca channels
what is the action of benzodiazepines?
enhances the binding of GABA to its receptor which causes opening of chloride channel
what is benzodiazepines used to treat?
anxiety, insomnia and epilepsy
what are psychomotor stimulants?
drugs that act as adrenergic nerve terminals
what does cocaine do?
blocks neuronal uptake of NA, increasing its concentration and blocks dopamine transporter and serotonin transporter
what is the name of the serotonin transporter?
SERT
what physiological effect does cocaine have?
mimics sympathetic activation such as tachycardia, hypertension and decreased GI motility
what does amphetamine do?
displaces NA from storage vesicles and reverses direction of uptake pump, increasing concentration in the cleft
what does LSD do?
agonist for serotonin receptors
what dies MDMA do?
releases 5-HT and blocks reuptake
what does psilocybin do?
chemically related to 5-HT so acts upon 5-HT2A receptors
what does tetrahydrocannabinol do?
activates CB1 and CB2 receptors, has analgesic and antiseptic properties
what does salvinorin A do?
K-opioid receptor agonist
what are CB1 receptors?
expressed in the CNS and have psychoactive effects
what are CB2 receptors?
expressed in immune system and haemopoietic cells
what is the CTZ?
chemoreceptor trigger zone in the medulla
what are the endogenous ligands?
AEA and 2-AG
