Drugs Of Abuse Flashcards
Briefly define substance use disorder according to DSM-V
Tolerance
(Need more or diminished effect)
Withdrawal
(Substance used to relieve or avoid withdrawal symptoms)
Define the common neural pathway of drugs of abuse.
Increase dopamine
Reward pathway
Major effects:
+euphoria
+omnipotence
+relaxation
Define the part in the brain where all drugs of abuse causes increased dopaminergic transmission
Mesolithic pathway
List MOA of psychostimulants
Amphetamines
Methylphenidate
Cocaine
Inc. NE, DA, serotonin
Cocaine + Methylphenidate:
no effect on 5HT!!
List desired and toxic effects of psychostimulants
Effects: \+euphoria \+hallucination \+strength \+dec. appetite \+long-term performance \+dec. need for sleep
Toxicity:
- cardiac arrhythmias
- psychosis
- seizures
List clinical use of psychostimulants
Amphetamines:
Anorexiant (obesity)
ADHD
Methylphenidate: ADHD
Cocaine: local anesthetic
Describe withdrawal syndrome and treatment of intoxication for
Psychostimulants
Withdrawal:
- dec. pleasure
- psychomotor retardation
- fatigue
- inc. appetite
Tx:
+control agitation = BNZ
+hyperthermia = ice
+HTN = nitroprusside or phentolamine
List MOA of marijuana
Stimulation of cannabinoid receptors
Dec. GABA = inc. DA release
List desired and toxic effects of marijuana
Stimulant phase
Depressive + munchies
Toxicity:
- Anticholinergic = tachycardia, dry mouth
- Bloodshot eyes
Describe clinical use for marijuana
Antiemetic effects
= dronabinol
Appetite promoting in AIDS and cancer patients = dronabinol + Nabilone
Describe withdrawal syndrome and treatment of intoxication for
Marijuana
None well characterized
List MOA of opioids
Agonist at mu receptors in Mesolimbic pathway
Dec. GABA = inc. DA
List desired and toxic effects of opioids
Effects:
Depressed mental status
Respiratory depression
Pinpoint pupils (miosis)
Describe clinical use of opioids
Moderate to severe pain
Describe withdrawal syndrome and treatment of intoxication for
Opioids
(Heroine, morphine, codeine, oxycodone)
Withdrawal:
- muscle aches
- autonomic hyperactivity
- GI: N/V/D
- neuro: restlessness
Tx of intoxication:
Respiratory support
Naloxone
Tx of withdrawal:
Methadone (substitution therapy)
Buprenorphine
Clonidine
List MOA for CNS depressants (ethanol)
Inc. endogenous opioids?
List desired and toxic effects of ethanol
Chronic effects:
Alcoholic fatty liver can eventually turn into cirrhosis and failure
Neurotoxicity: peripheral neuropathy, Wernicke-Korsakoff syndrome
Describe withdrawal syndrome and treatment of intoxication for
Ethanol
Withdrawal:
- Stage 1: tachycardia, epileptic seizures, tremor, N, sweating
- Stage 2: predelirium
- Stage 3: delirium
Tx: of intoxication:
Thiamine
Dextrose (IV)
Electrolytes
Tx of withdrawal:
Correct electrolytes
Thiamine
Sedatives
List the three major enzymes involved in ethanol metabolism and describe the reaction catalyze by them
Including cofactors and products
Alcohol-dehydrogenase
- takes ethanol into acetaldehyde
- cofactors: NAD+ into NADH
MEOS
- ethanol into acetalaldehyde
- cofactors: NADPH + O2 => NADP+ and water
Aldehyde-dehydrogenase
- takes acetalaldehyde into acetate
- cofactors: NAD+ => NADH
Describe elimination of ethanol including the 3 major routes
Liver
Lungs
Urine
Briefly explain why women are more susceptible to alcohol intoxication
Smaller amounts of alcohol-dehydrogenase in the liver
Briefly explain the reason for the zero order kinetics in ethanol metabolism
RLS is provision of NAD+
Cofactors in conversion of acetalaldehyde
Briefly describe the acute effects of alcohol in the CNS
Lower [] =
Euphoria, sedation, anxiolytic
Higher [] =
Slurred speech, ataxia, impaired judgment
List the major target organs of chronic ethanol use and briefly describe the underlying pathomechanism
Accumulation of fat int he liver
Inhibits TCA cycle and inhibits oxidation of fat because of excess NADH
