Ethanol

Question 1

What are the pharmacokinetics of ethanol?

Answer 1

Rapid absorption from the gut, peak in 40 minutes on an empty stomach

Question 2

What is the optimum concentration for bioavalibility?

Answer 2

20% Etoh

Question 3

Where is Etoh metabolized?

Answer 3

Some is metabolized in the liver while some is metabolized in the gut lumen

Question 4

breakdown of Etoh:

Answer 4

Etoh- (alcohol dehydrogenase) -acetylaldehyde- acetate

Question 5

What metabolize of Etoh is toxic?

Answer 5

acetyl aldehyde

Question 6

Pharmacodynamics of Etoh:

Answer 6

continuous CNS depressant. At low concentrations depress highly integrated functions of brain. Stimulant effects are do to the depression of inhibitory control mechanisms. Then followed by general impairment of nervous system: muddled thoughts and awkward movements

Question 7

CNS affects are genrally in proportion to ____________

Answer 7

the concentration in the blood

Question 8

Where is alcohol contraindicated?

Answer 8

epilepsy, in alcohol withdrawal heavy users can have seizures.

Question 9

Other effects of alcohol:

Answer 9

1. Good topical antiseptic, effective against gram - and + bacteria
2. Respiration- ventilator response to CO2 is depressed
3. GI tract- pronounced increase in gastric juices; contraindicated in peptic ulcers

Question 10

More effects of alcohol:

Answer 10

Kidney- diuretic effect due to inhibition of pituitary secretion of ADH (DEHYDRATION)
Liver- Accumilation of fat in the liver caused by: increased NADH/NAD ratio and mobilization of fat from peripheral tissues.
Cardiovascular- vasodilation
Physical Dependence

Question 11

Abstinence syndrome

Answer 11

Hyper-excitability when taken away. Commonly seen in heavy drinkers withdrawal.

Question 12

What is metabolic tolerance?

Answer 12

associated with increased metabolism, inducible enzymes in the liver, esp. microsomal oxidizing enzymes

Question 13

An alcoholic will have cross tolerance with barbiturates

Answer 13

know that

Question 14

What is functional tolerance?

Answer 14

Most of the pharmacodynamic effects of ETOH are due to the fact the ETOH changes the lipid environment of cell membranes, “fluidizes”. Changes the functional properties of many membrane. Chronic ETOH leads to more rigid membranes, more ETOH for the same effect.

Question 15

What is behavioral tolerance?

Answer 15

Recovery of the ability to function socially in spite of the drug. May refer as much to the how others perceive the drug user.

Question 16

What are the consequences of alcoholic dependence?

Answer 16

Physical- abstinence syndrome
Psychological- Dependence can lead to “purposeful behavior”, a condition where sustaining a dependence becomes a primary motivational factor.

Question 17

What is the etiology of alcoholism?

Answer 17

Behavior that establishes a pattern of tolerance, physical dependence, and withdrawal avoidance.
Animal models suggest genetic factors exist.
Child of an alcoholic parent has a 4x higher chance of also being an alcoholic.

Question 18

What is the treatment of acute alcoholism?

Answer 18

Immediate concern is to prevent respiratory failure.
During withdrawal there may be a need to prevent seizures and arrhythmias.
Benzodiazepines used to “taper off” over a period of weeks.

Question 19

What is the treatment of chronic alcoholism?

Answer 19

1. Behavioral modification
2. Aversive therapy, Disulfiram [Antabuse®] Prevents metabolism of acetaldehyde Not very toxic by itself – Ethanol and Disulfiram leads to build up of acetaldehyde
   headache, flush, nausea, vomiting
3. Opiate antagonist: Naltrexone

Question 20

Other alcohols

Answer 20

Methanol and Ethylene glycol:

Methanol a misguided ethanol substitute Very toxic breakdown products, e.g. formaldehyde, formic acid

Question 21

Treatment for methanol toxicity?

Answer 21

Treatment for toxicity: dialysis and ethanol to saturate metabolism