Drugs of Abuse Flashcards
Mechanisms of Addiction?
- Activation of mesolimbic dopamine system is prime target of addictive drugs
What are the CNS Depressants?
- Ethanol
- Benzodiazepines
- Barbiturates
Ethanol MOA, WS
MOA: works on GABAa receptors, Kir3/GIRK channels, Adenosine reuptake, Glycine receptors, NDMA receptors, and 5-HT3 receptors
WS: tremor, N/V, sweating, agitation, axiety, may be follow by hallucinations; seizures 24-48hrs, delrium tremens 48-72hrs; Tx with Dizepam/Chlordiazepoxide or Lorazepam/Oxazepam for elderly
What can be used for treatment of alcohol addiction?
- Disulfiram: aldehyde dehydrogenase inhibitor (aversion to drinking)
- Naltrexone: opioid antagonist (reduce craving)
- Acamprosate: NMDA antagonist to prevent relapse
Benzodiazepines and Barbiturates WS and treatment
WS: is rare but tremors, anxiety, perceptual disturbances, dysphoria, psychosis, and seizures; can be life threatening
Tx with Diazepam
What are the psychostimulants?
- Methylxanthines
- Cocaine
- Amphetamines
Methylxanthines MOA
Caffeine, Theophylline, & Throbromine
MOA: block presynaptic adenosine receptors > increase NE release
WD: fatigue and sedation
Cocaine MOA, action, WS
MOA: inhibits dopamine, NE, and serotonin reuptake
Action: CNS increase mental awareness, euphoria, paranoia after repeated doses, high doses is tremors/convulsions followed by respiratory and vasomotor depression; SNS potentiates action of NE > andrenergic causing tachycardia, HTN, mydriasis, diaphoresis
WS: dysphoria, depression, sleepiness, fatigue, cravings, bradycardia
Amphetamines (Methylphenidate) MOA, actions, Uses, WD
MOA: increase release of catecholamines and weak inhbitor of MAO
Actions: CNS due to release of dopamine causes increased alertness, decresed fatigue, depressed appetite, and insomnia; SNS increase NE release
Uses: Attention Deficit Syndrome and Narcolepsy
WD: increased appetite, sleepiness, exhaustion, and mental depression
Nicotine MOA, actions, WS, Tx
MOA: full agonist of nicotine receptor (ventral tegmental area for rewarding because dopamine release); high doses ganglionic blockade
Actions: euphoria, relaxation, improves attention/learning/problem solving/reaction time, appetite suppressant; high doses central respiratory paralysis and severe hypotension
WS: irritability and sleeplessness
Tx: Nicotine replacement therapy, sustained-release Bupropion, and Varenicline
Opioid WS, Tx
WS: dysphoria, lacrimation, rhinorrhea, yawning
Tx: Methadone or Buprenorphine; Naltrexone for detoxification
Marijuana MOA, uses
MOA: delta9-tetrahydrocannabinol and other cannabinoids bind CB1 mostly brain and CB2 mostly immune (Gi receptors)
Uses: anorexia assiociated with weight loss in pts with AIDS; N/V in cancer chemotherapy (second line)
What are the psychedelic agents?
- LSD
- Mescaline: LSD like
- Psilocybin: LSD like
- Phenciclidine
- MDMA
LSD MOA, actions?
MOA: agoinst effects at 5-HT2 receptors in CNS > hallucinogenic
Actions: somatic (mydriasis, HTN, tachycardia, increase body temperature, flushing, sweating, tremors, piloerection) and psychomimetic symptoms; if bad trip can use Diazepam
Phencyclidine (PCP) MOA
MOA: blocks reuptake of NE and dopamine and noncomptitive antagonism of NMDA receptors (dissociative properties)
Actions: violent or bizarre behavoir, psychosis, nystagmus, tachycardia, HTN, diaphoresis, miois, anesthesia, analgesia
Tx: parenteral benzodiazepines for violent behavoir and if seizure
