2. Ethanol
Mechanism of action: Ethanol
Ethanol enhances the action of GABA
through GABA-A receptor
It also inhibits NMDA receptor
Ethanol potentiates the action of BZD and
barbiturates and can result in fatal CNS
depression.
6. Continued
Unconsciousness, anesthesia and
cardiac depression: ~ or > 300 mg/dL
Lethal dose- ~ or > 500 mg/dL
#. Molecular MOA: induces GABA
action at GABA-A and inhibit
glutamate to NMDA-r.
7. Continued
2. Other organs:
Depression of heart [low dose] &
vaso-dilation
Uterine relaxant
Increases the effect of sulfonylureas
Boosts up the antiplatelet action of
aspirin.
8. Chronic effects
#. Both psychologic & physical dependence: An
abstinence syndrome
#. Liver: decreased gluconeogenesis, fat
accumulation ( NAD )- Hepatic dysfunction
Acetaminophen- to toxic metabolite
#. GIT: Causes inflammation & hemorrhage of
gut
9. Continued
#. Central nervous system:
Peripheral neuropathy: common
Wernicke- Korsakoff’s syndrome:
extra ocular muscle paralysis, ataxia,
confusion, ( delirium tremens)-
( Thiamin )
10. Continued
#. Cardiovascular system: hypotension,
anemia and MI
#. Endocrine effects: Gynecomastia,
salt retention, testicular atrophy
#. Fetal alcohol syndrome.
#. Neoplasia: Breast cancer etc.
11. Uses of Ethanol
1.External uses:
Solvent for many drugs
Vehicle for medicinal mixtures
To wash skin burn due to phenol
As a cool sponge
Disinfectant for skin & rubefacient in
liniments
12. Continued
2. Internal uses:
As a analgesic for trigeminal neuralgia
In methyl alcohol & ethylene glycol
poisoning
13. Drug interaction with alcohol
#. Pharmacokinetic
Enzyme induction on chronic
administration
• Enzyme inhibition on acute intake.
15. Treatment of Acute Alcohol
Intoxication
#. Supportive measure:
Prevent respiratory depression &
aspiration pneumonia
Maintain respiration and circulation
Fatal blood concentration: 400mg% &
legal limit of intoxication: 100% 7-10
g/h is metabolized
16. Continued
Give fluids and electrolytes
#. Pharmacological measure:
Give glucose to treat hypoglycemia
and ketosis
Thiamine [10 mg] is added to protect
against the Wernike-Korsakoff
syndrome
17. Treatment Alcohol Withdrawal
Syndrome
Prevent seizures, delirium, &
arrhythmia
Restore K, Mg, & Phosphate ions
#. Specific therapy:
A long acting sedative- hypnotic drugs:
e.g. Chlordiazepoxide, diazepam, etc.
Thiamine 10 mg is suggestive
18. Continued
Oxazepam is drug of choice in liver
disease
Phenytoin is administered for seizure
Propranolol: to treat tremor
19. Disulfiram
Inhibits acetaldeyde dehydrogease and
accumulates acetaldehyde
Induces flushing, throbbing headache, nausea,
vomiting, perspiration, hypotention and confusion
( few minutes to several hours )
Disulfiram ( 250mg ): at bed time.
21. The drugs reduce craving of
alcohol
Fluxetine
Bromocriptine
Naltrexone
Acamprosate
22. Methanol
#. MOA: methanol is
Metabolized to formadehyde and
formic acid by alcohol dehydrogenase
Severe acidosis and retinal damage.
#. Intoxication: Visual dysfunction,gut
distress, SOB, loss of conscious,
coma & death
23. Treatment of Methanol
Ethanol: 10% in D/W; loading dose 0.7
ml/kg; then 0.15 ml/kg/h )
Iv sodium bicarbonate for acidosis
Potassium for hypokalimea
Fluids and electrolytes
Keeps patient in dark room
Hemodialysis
24. Continued
Antidote: Fomepizole (100mg) iv is to
be given an inhibitor of Alcohol de-
hydrogenese
Calcium leucovorin reduces formate in
blood.
25. Ethylene glycol
Ethylene glycol poisoning: by
inhalation and skin absorption or by
intake
It is metabolized by ADH and
formation of oxalic acid- severe
acidosis and nephro-toxicity
26. Treatment
#. Supportive measure: same
#. Pharmacological measure:
Prompt ethyl alcohol intravenous
slowly to prevent toxic metabolite of
ethylene glycol
Fomepizole if necessary
