This document summarizes the toxicity and treatment of methanol (wood alcohol) poisoning. Key points include: - Methanol is metabolized to formaldehyde and formic acid, which are more toxic than methanol itself and can cause metabolic acidosis. - Symptoms of poisoning may take 1-24 hours to appear and include drunkenness, delirium, coma, and potentially blindness or death from respiratory depression. - Treatment involves gastric lavage, administering ethanol to prevent methanol metabolism, as well as hemodialysis, folic acid, and maintaining electrolyte and acid-base balance.

1. Introduction:
 Also known as wood alcohol
 Colorless, volatile liquid,
odour similar to alcohol,
burning taste.

2. Methyl Alcohol
Dr.J.A.Dabhi
Resident
S.B.K.S.M.I.R.C
Gujarat

3. Site of absorption
o Skin
o GIT
o Lungs

4. Metabolism:
Methanol
Formaldehyde
Formic Acid
Metabolic Acidosis

5.  Formaldehyde 33 times more
toxic than methanol.
 Formic Acid is 6 times more
toxic than methanol.

6.  Renal Toxicity
 Distributed in the tissues
having high water content, high
conc. Is found in vitreous body
and optic nerve, hence causes
optic neuritis.

7. Elimination
 About 80% excreted
unchanged from lungs.
 3-5% excreted unchanged in
urine

8. Signs/Symptoms
 Produces symptoms of
drunkenness like ethyl alcohol.
 Effects are more prolonged.
 Appearance of symptoms: 1
hour – 24 hours

9.  General signs of poisoning
 Odour present in breath.
 Effects on CNS is well marked
 Delirium, coma may last for
2-3 days
 Toxic effects on liver, kidney
and nervous system.

10.  Urine is strongly acidic and
contain acetone and trace of
albumin.
 Metabolic acidosis: Due to
excess of lactic acid and
respiratory depression

11.  Pupils: Dilated and fixed
 Photophobia, blurred vision
 Central & peripheral scotoma
 Decreased light perception
 Sudden loss of vision or
complete blindness due to optic
neuritis may occur.

12.  Retinal ganglion cells and
optic disc shows degenerative
changes.
 In fatal cases: Convulsions
 Death may occur from
respiratory depression

13.  Fatal Dose: 60-120 ml
 Fatal Period: 24-36 hours or
can be delayed for 2-4 days

14. Cause of death:
 Death is mainly due to
metabolic acidosis resulting
from production of organic
acids mainly, Formic Acid.
 CNS depression leading to
respiratory depression.

15. Treatment
 Gastric lavage: 5% Sod.Bic
 Ethyl Alcohol 50% 1ml/kg i.v.
every 2 hours for 5 days.
 Maintain blood alcohol level
of 100-150 mg%

16. Methyl Alcohol Ethyl Alcohol
Catalase
Unchanged
Methanol
Excretion
Acetaldehyde

17.  Haemodialysis is the
treatment of choice.
 Folic acid: 50-75 mg/ 4 Hrs
increases elimination of formic
acid.
 Dextrose, Vit.B1, phosphate

18.  Maintain serum electrolyte
to optimum level.
 Head low position.
 Keep airways clear.

19. Post-mortem Appearance
 Marked cyanosis
 Ab of PM clotting of blood
 Purple color due to pyridine
 Liver: fatty changes
 Kidney: tubular necrosis

20. Circumstances
 Accidently.
 Non availability of
beverages containing ethyl
alcohol.