The document provides an overview of barbiturates, including their definitions, classification, mechanism of action, uses, and toxic effects. It outlines the signs of barbiturate poisoning and recommended treatments, emphasizing that there is no specific antidote. The document also discusses postmortem appearances associated with barbiturate intoxication and references for further reading.

1. BARBITURATEPOISONING: A PRECISE
INSIGHT
BY-
VISHAL GALAVE
NAVSAHYADRI INSTITUTE OF
PHARMACY

2.  DEFINITION OF BARBITURATES:
VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY
“ DERIVATIVES of BARBITURIC ACID,
used as SEDATIVE-HYPNOTICS , and
also for the treatment of
EPILEPSY”………………

3.  CLASSIFICATION OF BARBITURATES:
VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY
1. ULTRA-SHORTACTINGBARBITURATES:
- Duration of action: >0.5 hours
- Examples include:
a. THIOPENTAL
b. METHOHEXITAL
2.SHORT-ACTINGBARBITURATES:
- Duration of action : > 3- 4 hours
- Examples include:
a. PENTOBARBITAL b. SECOBARBITAL

4. 3.INTERMEDIATE-ACTINGBARBITURATES:
- Duration of action : > 4 - 6 hours
- Examples include:
a. AMOBARBITAL
b. APROBARBITAL
c. BUTABARBITAL
d. BUTALBITAL
4.LONG-ACTINGBARBITURATES:
- Duration of action: >6-12 hours
- Examples include:
a. MEPHOBARBITAL
b. PHENOBARBITAL…………………

5.  MECHANISM OF ACTION & TOXICITY :
VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY
• BARBITURATES  Causes GENERALIZED DEPRESSION of neuronal activity in
brain
• DRUG  Interacts with BARBITURATE RECEPTOR  Leads to increase in
GABA-MEDIATED CHLORIDE CHANNEL CURRENTS  Causes SYNAPTIC
INHIBITION
• DRUG  also depresses CENTRAL SYMPATHETIC TONE & CARDIAC
CONTRACTILITY  Leads to HYPOTENSION……………………….

6.  GENERALUSESOF BARBITURATES:
1. SEDATIVE-HYPNOTIC
2. PRE-OPERATIVE SEDATION
3. GTCS
4. FEBRILE CONVULSIONS
5. STATUS EPILEPTICUS

7.  TOXICOKINETICS :
1. ORAL ROUTE  Preferred for SEDATIVE-HYPNOTIC action
2. I.V ROUTE  Preferred for :
a. STATUS EPILEPTICUS management
b. Induction/ maintenance of GENERALANAESTHESIA
3. Distributed widely
4. Undergoes HEPATIC OXIDATION to form metabolites , like:
A. ALCOHOLS
B. KETONES
C. PHENOLS
D. CARBOXYLIC ACIDS
5. Excreted as such in URINE/ as GLUCURONIC ACID conjugates…………………………

8.  ADVERSEEFFECTSOF BARBITURATES:
1. RESIDUALDEPRESSION(After the main effect of the drug ceases)
2. PARADOXICAL EXCITEMENT (especially in elderly)
3. HYPERSENSITIVITY REACTIONS :
- include:
A. Localized swelling of eyelid, lips or cheeks
B. Erythematous or exfoliative dermatitis

9.  TOXIC EFFECTSOF BARBITURATES:
1. Slurred speech
2. Ataxia
3. Lethargy
4. Confusion
5. Headache
6. Nystagmus
7. CNS depression
8. ComA
9.Shock
10.Constricted pupils

10. 11. Hypothermia
12. CUTANEOUS BULLAE
(BLISTERS)
13. Respiratory arrest or CV collapse…………………
FORMILD-MODERATEINTOXICATION:
- SLURRED SPEECH
FORHIGHERDOSES:
- ATAXIA - NYSTAGMUS
- HYPOTENSION
- HYPOTHERMIA
- RESPIRATORYARREST - COMA

11.  USUALFATAL DOSES:
VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY
1.FORPHENOBARBITONE:
6-10 GRAMS
2.FORAM0BARBITAL,SECOBARBITAL,PENTOBARBITAL:
2-3 GRAMS………………..

12.  POSTMORTEM APPEARANCES:
VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY
1. PERIPHERAL CYANOSIS
2. FROTH AT MOUTH AND NOSE
3. BARBITURATE BLISTERS, PRESENT ON:
- Buttocks
- Calves
- Forearms
4. HIGHLY CONGESTED LUNGS
5. STOMACH EROSION………………..

13.  TREATMENT OF BARBITURATE
POISONING  :
- There is no specific ANTIDOTE for BARBITURATE POISONING
- EMERGENCY&SUPPORTIVEMEASURES:
Include:
a. AIRWAY PROTECTION
b. ASSISTEDVENTILATION(IFNECESSARY)
c. Treat COMA, HYPOTHERMIA and HYPOTENSION if they occur
d. For COMA, focus on the following treatment principles:
* DEXTROSE : For ADULTS (50% solution, 50 ml. I.V), for CHILDREN (25% solution, 2
ml/kg I.V)
• THIAMINE : 100 mg (I.V)
• NALOXONE : Initially 0.4 mg I.V  If no response to therapy  give 2 mg I.V  if
no response to therapy  give 10-20 mg I.V

14. E. For HYPOTHERMIA, focus on the following treatment principles:
• If patient is not in CARDIAC ARREST REWARMSLOWLY, using BLANKETS,
WARM I.V FLUIDS
• If patient is in CARDIAC ARREST Use GASTRIC/ PERITONEALLAVAGE with
WARM FLUIDS , and perform CPR
• For VENTRICULAR FIBRILLATION  Use BRETYLIUM (5-10 mg I.V)
• Perform OPEN CARDIAC MASSAGE/ PARTIAL CARDIOPULMONARY BYPASS
under non-responsiveness of the above measures………………………..
F. For HYPOTENSION, focus on the following treatment principles:
• Use I.V FLUIDS/ LOW DOSE PRESSORS(DOPAMINE)
• Focus on PATIENT REWARMING
• FLUID CHALLENGE CONCEPT: Use NORMAL SALINE(10-20 ml/kg) / any
other CRYSTALLOID SOLUTION
VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY

15. • Give DOPAMINE (5-15 mcg/kg/min)
• If above measures are not effective  insert CENTRAL VENOUS PRESSURE(CVP)
MONITOR/ PULMONARY ARTERYCATHETER , to check :
1. If fluids are required
2.CARDIAC OUTPUT and SYSTEMIC VASCULR RESISTANCE, according to the
formula:
SVR= [80(MAP-CVP)]/ CO,
Where
MAP = MEAN ARTERIAL PRESSURE
CVP = CENTRAL VENOUS PRESSURE
• Normal value of SVR: 770-1500
• If CVP is low  give more IV FLUIDS
• If CO is low  give DOBUTAMINE/ DOPAMINE
• If SVRis low  give NOREPINEPHRINE (4-8 mcg/min)

16. G. Intubation
H. SUPPLEMENTAL OXYGEN
-DECONTAMINATIONPRINCIPLES:
1. FOR PRE-HOSPITAL DECONTAMINATION : Give ACTIVATED CHARCOAL (If
available)
2. FOR IN- HOSPITAL DECONTAMINATION :
- Give ACTIVATED CHARCOAL
- Focus on GASTRIC LAVAGE (In cases of MASSIVE INGESTION of BARBITURATES)
- ENHANCEDELIMINATION:
1. URINE ALKALINIZATION (Only for PHENOBARBITAL)
2. REPEATDOSEACTIVATED CHARCOAL (Only for PHENOBARBITAL)
3. HAEMODIALYSIS & HAEMOPERFUSION (In patients, not responding to SUPPORTIVE
CARE)… VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY

17.  BIBLIOGRAPHY/ REFERENCE:
VISHALGALAVE
NAVSAHYADRI INSTITUTE OF PHARMACY
1. ALBERTSON.E.T; “BARBITURATES”; “POISONING AND
DRUG OVERDOSE BY KENT.R.OLSON” ; 4TH EDITION;
MCGRAW HILL PUBLICATIONS; PAGE: 124-126
2. “ALCOHOLS &SEDATIVES: BARBITURATES”;
“TEXTBOOK OF FORENSIC MEDICINE& TOXICOLOGY
BY DR.V.V.PILLAY”; 17TH EDITION; PARAS MEDICAL
PUBLISHERS; PAGE: 598-599………………………