EtOH/Drug Abuse - Lichtblau Flashcards
What are some of the non-CNS effects of ethanol?
e.g. cardiovascular, GI, hepatic, renal
Cardiovascular - vasodilation, sense of warmth but body temp decreases, cardiomyopathy (chronic), conduction/rhythm defects
Liver - interference with oxidative metabolism of drugs, increases oxidative metabolism, increases hepatic synthesis of fat & its mobilization from peripheral tissues
Kidney - diuretic, decreased release of ADH release from pituitary, decreased reabsorption of water in renal tubule
GI - stimulate saliva/gastric acid, 10% increases gastric acid secretion, 15-20% secretion and motility are depressed (mucosal irritation), 40% mucosal inflammation, hyperemia (excessive loss of blood/loss of plasma proteins)
What is the action of ethanol on the CNS?
CNS Depressant:
- initial stimulation due to depression of inhibitory control (“Disinhibition Euphoria”)
- Generalized CNS depression (thought and motor fxns that are most dependent on training and previous experience are first affected)
- Anesthetic (near lethal concentrations)
- Analgesic
What is the nutritional impact of ethanol?
+7 kcal/g
+carbohydrates (no nutritional value)
+malabsorption of vitamins (Wernike-Korsakoff)
What is ethanol’s possible mechanism(s) of action?
Membrane disordering or fluidizing effect
- similar to anesthetics
- may be responsible for toxicity
- alters the characteristics of several NT receptors and enzyme system
What is meant by fetal alcohol syndrome (FAS)?
- Placental transfer of alcohol (gets to embryo and fetus)
- Symptoms include: microcephaly, abnormal facial structure, cardiac defect, mental retardation, impaired immune system
- Known risks occur when consumption is greater than 2.5 oz. ethanol/day
What are the therapeutic uses of ethanol?
- Antiseptic/disinfectant (70%)
- Head-cold (old English remedy, basically just get rest)
- Aphrodisiac (Macbeth, Shakespeare)
- Antidote to methanol intoxication
What are major drug interactions with ethanol?
Disulfiram - interferes with aldehyde dehydrogenase, leads to excessive acetaldehyde levels, Antabuse (alcohol makes person very sick)
Oral hypoglycemic agents, Cephalosporins & Anti-fungal drugs may produce a similar effect
CNS depressants - additive or supra-additive effects
Salicylates - increased GI bleeding
What is the basis for treatment of Methanol toxicity treatment?
Methanol –> Formaldehyde –> Formic Acid (by alcohol dehydrogenase)
Blurred vision –> severe acidosis/blindness –> coma –> death
***Acidosis and retinal damage are probably due to formation of formic acid.
How do you treat Methanol Toxicity (overdose)?
- Maintain respiration
- Induce emesis
- ***Reduce acidosis by treating with bicarbonate or other alkali until urinary pH = 7.5
- Administer ethanol (competes with metabolism of methanol by alcohol dehydrogenase)
What is the basis for treating Ethylene Glycol toxicity?
- Antifreeze (looks like water and tastes sweet), children accidentally consume
- renal failure due to calcium oxalate crystal blockages
- vomiting, ataxia, weakness, flaccid paralysis, convulsions, coma, death
- metabolic acidosis due to build up of formic acid
- cardiovascular dysfunction (glycolic acid & oxalic acid)
How do you treat Ethylene Glycol Toxicity?
- Symptomatically (emesis, acidosis, convulsions)
- Metabolic competition - with Ethanol (100x greater affinity for alcohol dehydrogenase)
- Fomepizole - inhibits alcohol dehydrogenase ($4000 per course)
What are the classes of prescription drugs which are of most concern as abused substances?
- Opioids
- Anxiolytic-Sedative-Hypnotics
- CNS Stimulants
What are appropriate and inappropriate uses of controlled prescription drugs?
Opioid
- appropriate: relief of pain
- inappropriate: to feel indifferent to environment (take mind of bad state)
Anxiolytic-Sedative-Hypnotics:
- appropriate: anxiety or insomnia
- inappropriate: to induce disinhibition euphoria (same effect as alcohol), white collar alcohol (no bad breath)
CNS Stimulants:
- appropriate: narcolepsy, ADHD, appetite suppression
- inappropriate: increase wakefulness, attentiveness, and athletic performance
What are psychoactive drugs?
Drugs that alter behavior:
-in a pleasurable way (positively reinforcing manner)
What is physical dependence?
Change at the cellular level
-if you take the drug away –> withdrawal syndromes (sometimes life-threatening symptoms)
(may/may not be present in stimulants, but present in opioids, barbs, & benzos)
