Drugs of Abuse Flashcards
what do all addictive drugs activate
the mesolimbic dopamine system
what are the drugs of abuse that are CNS depressants
Ethanol
Benzodiazepines
Barbiturates
mechanism of action of ethanol
influences several cellular functions –> GABA-A receptors, Kir3/GIRK channels, adenosine reuptake, glycine receptors, NMDA receptors, 5-HT3 receptors
preferred drug of choice for treating alcohol withdrawal syndrome
Benzodiazepines
Benzos used for withdrawal syndrome in elderly and those with liver disease and why
Lorazepam and Oxazepam because they do not undergo phase I metabolism with CYP3A4 so no liver involvement
FDA approved treatment for alcoholism
Naltrexone
Acamprosate
Disulfiram
how does disulfiram work in treatment of alcoholism
- inhibitor of aldehyde dehydrogenase causing an aversion to drinking
- if ethanol consumed while taking disulfiram, acetaldehyde accumulation –> nausea, headache, flushing, hypotension
how does naltrexone work in treatment of alcoholism
-opioid receptor antagonist that reduces craving for alcohol
how does acamprosate work in treatment of alcoholism
NMDA receptor antagonist
long term use of alcohol –> hyperactive glutamate system that persist after alcohol consumption ceases –> drug prevents relapse to alcohol drinking
antiepileptic that can be used to treat alcoholism but not FDA approved and its mechanism
Topiramate –> decreases mesolimbic dopamine release after alcohol and decreases craving
what are benzos commonly used to treat
insomnia and anxiety disorders
describe benzos and barbiturates in term of physical dependence and addiction
both can lead to physical dependence but vary rarely addiction
what are the psychostimulants
Cocaine
Amphetamine
Methylxanthines
what are examples of methylxanthines
Caffeine
Theophylline
Theobromine
found in coffee, tea, chocolate, soda
mechanism of action of methylxanthines
block adenosine receptors –> removing the inhibition of NE release –> act as stimulant
also adenosine promotes sleep and drowsiness so blocking it leads to insomnia and alertness
stimulate secretion of HCl –> so not to be used if one has peptic ulcers
uses of methylxanthines
Theophylline is used in chronic asthma
Caffeine and ergotamine for migraine
what is the lethal dose of caffeine and what does it lead to
10g of caffeine which is about 100 cups –> arrhythmias
mechanism of cocaine
inhibits reuptake of dopamine, NE, and serotonin
how do you identify a user of cocaine
presence of benzoylecgonine in urine
mechanism of amphetamine (derivates are methamphetamine and methylphenidate)
- increases release of catecholamine neurotransmitters including dopamine
- weak MAOI
behavioral effects similar to cocaine
uses of amphetamines
Attention Deficit Syndrome (ADHD)
Narcolepsy
mechanism of action of nicotine
selective full agonist of nicotinic receptors –> involves ventral tegmental area where nicotinic receptors are expressed on dopamine neurons
FDA approved treatment for cessation of smoking
Nicotine Replacement Therapy
Buproprion
Varenicline
mechanism and AE of varenicline
- partial agonist at neuronal nicotinic acetylcholine receptors in the CNS
- suicidal thoughts, mood changes, vivid nightmares
most commonly abused opioids
heroin, morphine, codeine, oxycodone
among health care professionals: meperidine and fentanyl
drugs used for opioid withdrawal (separate based on classes)
opioid agonists: Methadone and Buprenorphine
alpha 2 agonists: clonidine and lofexidine
opioid antagonist: naltrexone
produces most of the pharmacological effects of smoked marijuana
THC - Tetrahydrocannabinol (Dronabinol)
mechanism of marijuana
works via Gi –> inhibits adenylyl cyclase, open K channels, close Ca channels
AE of THC
increased HR, decreased BP, reddening of conjunctiva
uses of therapeutic THC – dronabinol
- Anorexia associated with weight loss in AIDs patients
- nausea and vomiting seen in cancer chemo patients
what are the psychedelic agents
LSD Mescaline Phencyclidine (PCP) Psilocybin MDMA
mechanism of action of hallucinogens (LSDs)
agonistic effects of 5-HT2 receptors in the CNS –> psychomimetic symptoms (hallucinations) and sympathomimetic symptoms (mydriasis, hypertension, tachycardia, flushing, sweating etc)
AE of LSD
bad trips – severe agitation
mechanism and clinical features seen in PCP
competitive antagonist of NMDA receptors –> NYSTAGMUS while awake and agitated, violent or bizarre behavior, miosis, anesthesia, analgesia, hypertension,
what is used to treat the extreme violent psychotic behavior seen in use of PCP
benzos
mechanism and clinical features of MDMA (ecstasy)
increases concentration serotonin in synaptic cleft by working on serotonin transporter –> tachycardia, muscle aches, agitation, hyperthermia, and seizures
what are the inhalants
Volatile Organic Solvents (paint thinners etc)
Organic nitrites
Nitrous Oxide
use of nitrous oxide
intoxicant used by medical personnel that causes euphoria and analgesia before loss of consciousness
usually 35% N2O mixed with O2
what happens if given 100% nitrous oxide
asphyxia and death
name the organic nitrite and its use
Amyl nitrite – treatment of angina
what are anabolic steroids used for
increase muscle mass and definition
