This document discusses alcohol and its metabolism and effects on the body. It notes that alcohol is metabolized in the liver through alcohol dehydrogenase and acetaldehyde dehydrogenase into acetaldehyde and acetic acid. It also inhibits NMDA receptors and calcium channels while enhancing GABA effects in the brain. Chronic alcohol consumption increases risks with medications like paracetamol and during pregnancy can cause fetal alcohol spectrum disorders. Disulfiram inhibits aldehyde dehydrogenase, causing a build up of toxic acetaldehyde when alcohol is consumed and resulting in an unpleasant reaction.
5. Alcohol has been shown to enhance GABA release at GABAA sites
in the brain .
It is also inhibits NMDA type of excitatory amino acid receptors
(operating through cation channel).
Some studies suggest that cerebral nicotinic cholinergic receptor
may also be one of the target of alcohol action.
Ethanol can indirectly reduce neurotransmitter release by
inhibiting voltage sensitive neuronal Ca++ Channels .
6. Ethanol is metabolised first to acetaldehyde and then to acetic acid. Two major pathways
of alcohol metabolised to acetaldehyde, which take place in liver have been identified.
7. Alcohols have many pharmacological action on body .
These are on –
• Brain
• Liver
• Heart
• Blood
• Muscle
• Skin
• Stomach
• Kidney
• Nervous System
• Endocrine Effect
8. • Psychological and medical supportive measures are
needed during withdrawal.
• Many CNS depressants like barbiturate , phenothiazines,
chloral hydrate have been used as substitution therapy in
the past (to suppress withdrawal syndrome) but
benzodiazepines(chordiazepoxide, diazepam) are the
preferred drugs now. These drugs have a long duration of
action and can be gradually withdrawn later.
9. Chronic consumption of alcohol increases risk of hepatotoxicity by Paracetamol.
All cerebral depressants like hypnotics, sedatives and anti-histamines can have
synergistic effect with ethanol.
Chronic alcoholics are relatively tolerant to use of general anesthetics like
Halothane .
Alcohol enhances the hypoglycemic effects of insulin and sulfonylureas.
Some alcoholic drinks like beer or wine contain tyramine, which is sufficient to
cause Hypertensive crisis in patients .
Aspirin and other NSAIDs cause more gastric bleeding when taken with alcohol.
10. Alcohol is seldom prescribed medically. However , it is rampantly
consumed. Intake of alcohol should be avoided by-
1. Patients with peptic ulcer, hyperacidity and gastroesophageal reflux
disease
2. Severe liver disease patients.
3. Unstable personalities: they are likely to abuse it and become excessive
drinkers.
4. Pregnant women: Even moderate drinking during pregnancy can produce
resulting in intrauterine and postnatal growth
retardation, low IQ offspring, microcephaly and other abnormalities, and
immunological impairment causing increased susceptibility to infections.
11. • As a skin antiseptic (76% v/v), alcohol is most effective.
• It has astringent action.
• It is used to treat methanol poisoning.
• Alcoholic sponges have been used to reduce body temperature in fever.
• As a local Rubefacient.
• As a diluent.
• As a pain reliever.
• As a preservatives.
12.
13. It is an aldehyde dehydrogenase inhibitor .
It prohibits the activity of Aldehyde dehydrogenase found in the liver .
When alcohol is ingested after taking disulfiram , the concentration of
acetaldehyde in tissues and blood rise and a number of highly distressing
symptoms (aldehyde syndrome) are produced promptly.
These are - flushing, burning sensation , headache, perspiration, uneasiness,
tightness in chest, dizziness, vomiting, visual disturbances, mental confusion,
postural fainting and circulatory collapse.
Duration of the syndrome ( 1- 4 hours) depends on the amount of alcohol
consumed .
14. Ethanol
(alcohol) Acetaldehyde Acetate
NAD+ NADH
NAD+ NADH
Alcohol
dehydrogenase
Acetaldehyde
NAD+
NADH
Disulfiram
Alcohol
dehydrogenase
Production of Aldehyde
dehydrogenase prohibited
Aldehyde
dehydrogenase
X
15. Side effects of disulfiram are
infrequent include rashes, metallic
taste, nervousness and abdominal
upset.
Side Effects :-