Methanol Overdose/Poisoning

Question 1

Where is methanol present.

Answer 1

In some antifreeze products.
Industrial solvents.
Low concentrations in some screen washes and methylated spirits.

Question 2

What is the cause of methanol’s toxicity.

Answer 2

Although it is not of high intrinsic toxicity, it is converted via alcohol dehydrogenase to toxic metabolites that are largely responsible for its clinical effect.

Question 3

What are some early features of methanol poisoning. (8)

Answer 3

Ataxia. 
Drowsiness. 
Headache. 
Confusion. 
Vertigo. 
Dysarthria. 
Nystagmus. 
Vomiting.

Question 4

What are the later features of methanol poisoning. (6)

Answer 4

Metabolic acidosis. 
Tachypnoea. 
Coma. 
Seizures. 
Optic disc and retinal oedema (blurred vision). 
Impaired pupil reflexes.

Question 5

What is a consequence of methanol poisoning. (2)

Answer 5

Blindness may be permanent.

Parkinsonian-like signs.

Question 6

What are the metabolic products of methanol. (2)

Answer 6

Formaldehyde.

Formate.

Question 7

What does the mortality of methanol poisoning correlate to.

Answer 7

With the severity and duration of metabolic acidosis.