Alcohols and ancholic patients drugs pdf

Alcoholic drug and treatments

1. ALCOHOLS

2. ETHYL & METHYL ALCOHOLS
ETHYL ALCOHOL (Ethanol)
•Alcohols are hydroxy derivatives of aliphatic hydrocarbons.
•When unqualified, 'alcohol' refers to ethyl alcohol or ethanol.
•It is a CNS depressant that can result in psychological &
physical dependence.
•Pharmacology of alcohol is important for
–its presence in beverages (which have been used since
recorded history),
–alcoholism and alcohol intoxication, rather than as a
medicinal substance.

3. ETHYL & METHYL ALCOHOLS
•FORMS OF ALCOHOL
1.Absolute alcohol 99% w/w ethanol (dehydrated alcohol).
2.Rectified spirit 90% w/w ethyl alcohol produced from
fermented mollases, by distillation.
3.Methylated spirit (industrial): It can be used as antiseptic
(antiseptic concentration 70 to 90%) and astringent.
4.Alcoholic beverages

4. Cont..
•PHARMACOKINETICS




•Metabolism of alcohol follows zero order kinetics, i.e. a
constant amount (8–12 ml of absolute alcohol/hour) is
degraded in unit time, irrespective of blood concentration

5. Cont..
•TOXICITY
A.Side effects of moderate drinking:
–Nausea, vomiting, flushing, hangover, traffic accidents.
B.Acute alcoholic intoxication:
–Unawareness, unresponsiveness, stupor,
–Hypotension, gastritis, hypoglycaemia, respiratory
depression, collapse, coma and death.

6. Cont..
•Treatment of Acute Alcoholic Intoxication :
–Gastric lavage is helpful only when the patient is brought
soon after ingesting alcohol, which is rare.
–Maintenance of patent airway & prevention of aspiration.
–Supportive treatment, maintenance of fluid and
electrolyte balance and correction of hypoglycaemia
–Thiamine (100mg in 500ml glucose solution infused i.v.)
–Recovery can be hastened by haemodialysis.

7. Cont..
•Alcohol Withdrawal syndrome
–When a physically dependent subject stops drinking,
withdrawal syndrome appears within a day.
–It consists of anxiety, sweating, tachycardia, tremor,
impairment of sleep, confusion, hallucinations, delirium
tremens, convulsions and collapse.

8. Cont..
•Treatment of Alcohol Withdrawal syndrome:
–Psychological and medical supportive measures
–Benzodiazepines (Diazepam) are the preferred drugs.
These have a long duration of action and can be
gradually withdrawn later.
–Naltrexone: The post-addict treated with the long-acting
opioid antagonist naltrexone does not experience the
same pleasurable effect on taking alcohol; reinforcement is
weakened.

9. Cont..
•CLINICAL USES
–As antiseptic (concentration 70 to 90%)
–Rubefacient and counterirritant for sprains, joint pains
–Rubbed into the skin to prevent bedsores.
It should not be applied on already formed sores.
–Reflex stimulation in fainting/hysteria: 1 drop in nose.
–To treat methanol poisoning

10. Cont..
DISULFIRAM - Aldehyde Dehydrogenase Inhibitor
•It inhibits the enzyme
aldehyde dehydrogenase
probably after conversion
into active metabolites.

11. Cont..
•When alcohol is ingested after taking disulfiram, the
concentration of acetaldehyde in tissues and blood rises and a
number of highly distressing symptoms (aldehyde syndrome)
are produced promptly
•These are — flushing, burning sensation, throbbing headache,
perspiration, uneasiness, tightness in chest, dizziness,
vomiting, visual disturbances, mental confusion, postural
fainting and circulatory collapse.

12. Cont..
METHYL ALCOHOL (Methanol, Wood alcohol)
•Methyl alcohol is added to industrial rectified spirit to render
it unfit for drinking.
•It is only of toxicological importance.
•Mixing of methylated spirit with alcoholic beverages by
bootlegers or its inadvertent ingestion results in methanol
poisoning

13. Cont..
•Methanol is metabolized to formaldehyde and formic acid by
alcohol and aldehyde dehydrogenases respectively

14. Cont..
•Methanol Poisoning
–Even 15ml of methanol causes blindness & 30ml has
caused death; fatal dose is regarded to be 75–100 ml.
–Clinical features of methanol poisoning:
Vomiting, headache, epigastric pain, uneasiness,
Disorientation, tachypnoea, dyspnoea, bradycardia and
hypotension.

15. Cont..
–Delirium and seizures may occur and the patient may
suddenly pass into coma.
–Acidosis is prominent
–The specific toxicity of formic acid is retinal damage:
Blurring of vision, followed by blindness always precede
death which is due to respiratory failure.

16. Cont..
•Treatment of Methanol poisoning
–Keep the patient in a quiet, dark room; protect the eyes
from light.
–Gastric lavage with sodium bicarbonate if the patient is
brought within 2 hours of ingesting methanol.
–Supportive measures to maintain ventilation and BP
–Combat acidosis by i.v. sodium bicarbonate infusion:
Prevents retinal damage and other symptoms.

17. Cont..
–Ethanol (10% in water) is administered through a
nasogastric tube.
Ethanol is preferentially metabolized by alcohol
dehydrogenase over methanol.
It saturates alcohol dehydrogenase & retards methanol
metabolism.
This helps by reducing rate of generation of formaldehyde &
formic acid.
Alcohol blood level needs to be repeatedly measured.
Treatment has to be continued for several days.

18. Cont..
–Haemodialysis: Clears methanol as well as formic acid and
speeds up recovery.
–Fomepizole: Specific inhibitor of alcohol dehydrogenase
Drug of choice for methanol poisoning by decreasing its
metabolism.
–Folate therapy: Calcium leucovorin 50 mg injected 6 hourly
has been shown to reduce blood formate levels by
enhancing its oxidation.