Management of organophosphates poisoning.

2. (AMMARA BATOOL AND MUNAWAR SULTANA

3. AMMARA BATOOL
Palvasha Gilani
Munawar Sultana

4.  Overview of Mechanism of poisoning.
 Types and routes.
 Treatment protocol.
 Monitoring and prevention.
 Summary.
 References.

6. Accidental Oral
Suicidal Inhalation
Homicidal Dermal
Occupational Eye contact

7.  First aid
 Supportive therapy
 Decontamination
 Pharmacologic Management
1) Atropine
2) Pralidoxime (2-PAM)

8.  Wear gloves and aprons to protect
themselves against clothing, skin and gastric
fluid of the patient.
 May lead to pneuomonitis.

9. Before admitting in ED.
 Remove contaminated clothes carefully.
 Wash the skin with running water for at
least 15 minutes.
 Alcohol wash.
 Surgical scrub kit.

10. Airway control and adequate oxygenation are
paramount in organophosphate (OP) poisonings.
 Intubation may be necessary in cases of
respiratory distress
Immediate aggressive use of atropine may
eliminate the need for intubation.
Succinylcholine should be avoided because it is
degraded by acetylcholinesterase (AChE) and
may result in prolonged paralysis.

11. Ingestion of poison within hour.
 Gastric lavage.
Gastric lavage decreases absorption by 42% if done at 20
minutes and by 16% if performed at 60 minutes
No human studies in OP poisoning showing benefit
of gastric lavage.
 Activated charcoal. (adsorbent)
Adult Dose = 25-100g dissolved in 200 ml of water.
Paediatric dose = 15 ml/kg body weight. Or
1g/kg

12. Common brand = Atropin ( 1mg/ml)
Dose
 Given IV (rapid IV injection less than 10 sec)
 Slow or low dose paradoxical bradycardia
 0.05 to 0.1mg/kg in children
 2-5 mg in adults
 Repeat after 5-10 mins until symptoms
resolve
 May require large doses over a period of
several days until activity resolved.

13. Mechanism of action :

14.  ADR:
 SLUD,Tachycardia, dilatation of pupil
 Contraindication:
Paralytic Ileus and IHD.
 Treatment:
Physostigmine in case of Atropine overdose.

15.  Protopam/ 2-pyridine aldoxime methiodide.
 Common brand : Contrathione. (2g vial)
 .Administer within 36-72 hrs of exposure.
 In Organophophate poisoning 2-PAM within
24 hrs
 After 36-72 hrs permanent binding of
organophospahte with esteric site of enzyme

16.  Breaks the bond between cholinesterse and
organophosphates and restore enzyme.

17. Dose :
 25-50 mg/kg upto 1g IV over 5-20 minutes.
 Repeat after 1 hr, if needed then again (muscle
spasm)
 Continuous IV infusion
 In adults: 2-4 mg/kg/hr preceded by a loading dose of
4-5mg /kg .
 In children: 10-20 mg/kg/hr preceded by a loading dose of
15- 50mg /kg.

18.  Use in combination with Atropine .
 First establish atropine symptoms than
administer it.
 Contraindication:
Allergic

19. Characteristics Atropine Pralidoxime
Interaction Synergistic with
Pralidoxime
Reduce the dose of
atropine
Indication Any anticholinesterase
agent.
Typically needed for
organophosphates.
Primary site of action Muscarinic and CNS Nicotinic > muscarinic >
CNS
Adverse effects Hallucination, coma,
tachycardia
Dizzziness, Diplopia,,
tachycardia, headache.
Daily dose 2-1600mg 1-12g
Total dose 2-11,422mg 1-92g

20.  For convulsions give diazepam 5-10 mg IV
slowly
 (Paediatric dose 0.2 mg/kg).
 Repeat if necessary. Up to 40 mg/day can be
given orally as maintenance dose.
 Continue diazepam for 3-4 days after
convulsions have been controlled. 10 ml of
10% calcium gluconate IV can also be used to
control convulsions.

21.  Vital signs :
 (Heart rate, rate of respiraton, BP ).
 Ventilatory adequacy (pneumonia)
TLC, blood gases.
 Chest radiograph (pneumonitis and
pulmonary edema(
 Long-term follow up.
 Workers-periodic monitoring.

22.  1970 – Endrin
 1976 – DDT
 1980 – Chlordimeform
 1980 – Dieldrin
 1980 – Phosphamidon
 1980 –Thallium sulpht.
 1984 – 2,4,5-T
 1984 – Ethyl parathion
 1984 – Methyl
 parathion
 1986 - Aldrin
 1986 – Lindane
 1987 – HCH (mixed
Isomers)
 1987 – Mercury cpds.
 1988 – Arsenic (arsenites
and arsenates)
 1988 – Hepatachlor
 1989 – Leptophos
Captafol
 1990 –Dichloropropane

24.  Pharmacotherapy handbook by JosephT.DiPiro,
Ninth edition,Ch # 10, Pg # 79 and 80.
 Medscape.
 Google search engine.