Ethyl alcohol and methanol are colorless liquids that are sometimes abused as intoxicating substances. Ethyl alcohol causes stages of excitement, incoordination and narcosis in acute poisoning. Chronic use can lead to alcoholism. Methanol poisoning causes symptoms like dizziness, headache and nausea initially, then metabolic acidosis, convulsions and blindness or death. Treatment for both involves stomach lavage and supportive care; ethanol is used as an antidote for methanol poisoning. Chronic use of either can have serious medical and legal consequences.
7. ETHYL ALCOHOL
• Introduction: It is a colourless, transparent, volatile liquid
which has a spcific odour of spirit. Its is extremely
hygroscopic.
• Poison classification: Inebrient cerebral poison
• Synonym: Grain alcohol, ethanol
• Chemical poison: C2H5OH
• Boiling point: 78.4° C
8. Uses of alcohol
• It is used to dissolve bromine, iodine, resins,
volatile oils.
• It is an antiseptic.
• Alcoholic beverages
• Preservation(rectified spirit)
• Cough syrups
• Perfumes ,mouth washes
ACUTE POISONING
• This may result from consumption of any
preparation containing alcohol either in small doses
at short interval, or in one big dose.
• While a few cases of intoxication from inhalation of
vapours are on record, this route cannot be
regarded as being of toxicological significance.
• Alcohol tends to produce three stages viz.
9. 1.Stage of excitement
2. Stage of incoordination
• It is also called stage of confusion
• Muscular incoordination leads to staggering gait
• Slurred speech
• Blurred vision
• Nausea and vomiting
• Hiccups
• Dirty and dishevelled appearance
• Dilated pupils
10. • Medicolegally it is important stage as offences are
committed during this stage.
3.Stage of narcosis
• Also called stage of coma
• Person only respond to strong stimuli
• Pulse rate increases
• Temperature decreases
• Dryness of mouth and tongue
• Pupils may be contracted
• Macewan's sign: On stimulation on the subject,eg by
pinching his neck or face, I pupils dilate initially and
slowly return to their original size.
ETHANOL TOXICITY
• Cause of death: asphyxia due to respiratory paralysis
• Fatal dose: 150 to 250ml of absolute alcohol or
0.35%concentration of alcohol in blood
• Fatal period: 12-24 hours
11. TREATMENT
• Stomach should be lavaged with care with 5%
solution of sod.bicarbonate in warm water.
• Patient should be kept warm.
• Vit. B6 is administered in dosage of 50-100 mg
• Artificial respiration may be necessary along with
oxygen inhalation.
Intravenous administration of flumezenil(3 mg) for
respiratory depression.
POSTMORTEM APPEARANCE
• Clothes may have stained by vomit material
• Rigor mortis remain for longer period
• Delay in putrefaction
• Smell of ethanol
• Liver, brain and lungs are congested
• Medicolegal importance: humans affected by
alcohol die by crimes influenced by alcohol or
accidents more than its poisoning.
12. CHRONIC POISONING
• This results from continous use of alcohol and is
characterised by a gradual physical, mental and
moral deterioration (alcoholic dementia)
• It is also known as alcoholism.
• Symptoms:
• Deep desire for alcohol
• Withdrawl symptoms
•
Restrict the use of alcohol.
13. TREATMENT
• Balanced diet.
• Multivitamins.
• Vit E for clotting disorders.
• Folic acid.
• For withdrawl symptoms: diazepam, carbamazepine.
Aversion therapy: Disulphiram 0.2-0.75 gm/day orally.
METHANOL
It is obtained from destructive distillation of molasses.
• It is colourless liquid which have a light spirit like
odour.
• Classification: Inebrient cerebral poison.
• Synonym: Methanol, wood spirit
• Uses:
To varnish furniture
Antifreeze
Paint remover
14. SIGNS AND SYMPTOMS
In small doses
• Dizziness
• Headache
• Nausea and vomiting
• Abdominal pain
In moderate doses
• Tachycardia
• Drowsiness
• Mydriasis (dilation of pupil)
In high doses
• Metabolic acidosis
• Convulsions
• Retinal oedema
• Coma
• Respiratoy failure and death
15.
16. • Fatal dose: 60-250 ml
10-15 ml cause blindness
• Fatal period: 24-36 hrs
TREATMENT
• Stomach wash by 5% solution of sod.bicarbonate in
warm water.
• Convulsions- paraldehyde I. M
• Acidosis- 2gm sod. bicarbonate solution in 250 ml of
water.
• Hypokalaemia potassium salts.
• Cover the eyes from light.
• Symptomatic treatment
• Ehanol is considered as antidote for methanol.
• Ethanol has higher affinity for alcohol
dehydrogenase enzyme than methanol and hence
prevent th formation of formaldehyde and formic
acid.
17. POSTMOTEM APPEARANCE
• Mucus membrane of stomach and intestine are
congested
• Lungs are congested with oedema
• Brain and its meninges are congested
• Kidney-tubular degeneration
• Eyes-degenerative changes in retina, optic disc.
• Liver-necrobiosis
MEDICOLEGAL IMPORTANCE
• Accidental poisoning
• Methanol mixed cheap,ellicit alcohol abuse
• Abuse of paint remover, lather dyes, windshield
washing fluids or ingeation of its vapours.