barbiturate poisoning is the poisoning caused due to overdose of the barbiturate drug e.g.phenobarbitone .

1. BARBITURATE
POISONING

2. BARBITURATE POISONING
•It is the poisoning caused due to overdose of
barbiturates e.g.. Phenobarbitone.
•The lethal dose of 6 – 10 gm is sufficient to cause acute
barbiturate poisoning .
•Short acting barbiturates are more lethal than short
acting ones .
•Coma is more Sevier with barbiturate poisoning .

3. CLINICAL MANIFESTATIONS :
•Respiratory depression
•Slow and shallow breathing
•Hypotension
•Skin eruptions
•Renal failure
•Cardiovascular collapse

4. MECHANISM OF ACTION OF POISONING
BARBITURATE
CAUSING GENERALIZED DEPRESSION
DRUG INTERACTS WITH BARBITURATE RECEPTORS
LEADS TO INCREASE IN GABA-mediated chloride channel currents
CAUSING SYNAPTIC INHIBITION

5. NOTE : while this mechanism takes place ,there also occurs a central
sympathetic tone depression leading to hypotension .
TREATMENT : The barbiturate poisoning has no specific antidote but there are
some measures taken which are as follows :
Gastric lavage followed by administration of activated charcoal to prevent
further absorption of barbiturates.
Maintenance of patent airway , adequate ventilation and oxygen
administration
General supportive measures like maintenance of blood pressure and body
fluid balance .
Forced alkaline diuresis with sodium bicarbonate , a diuretic (frusemide) and
IV fluids which will help to fasten the excretion of long acting barbiturates .

6. Hemodialysis should be done especially if there is a renal failure.

7. • Forced alkaline diuresis is a procedure commonly used for treatment of
barbiturate poisoning.
• In this 1.5-2.0 litres of I.V. fluids is administered per hour for 3 hours .
• It is done to maintain urine volume up to more than 500 ml per hour.
• Urine pH is measured every 30 min and the pH of between 7.5 and 8.5 is
maintained.
• Alkaline diuresis should be discontinued after 1 hour if the urine flow is
less than 3 ml per minute.
• Otherwise , it should be continued beyond 3 hours at 1 litre per hour until
blood salicylate is reduced to or less than 2.5 m mol per litre.