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Organo-Phosphorus and Carbamate Compounds Poisoning



These can be absorbed through the skin, ingested or inhaled. Examples:
• Organophosphorus – Malathion, Parathion, Tetraethyl Pyrophosphate (TEPP), mevinphos and
• Carbamates – methiocarb and carbaryl.

Risk Factors

Signs and symptoms

Diagnostic criteria

• Vomiting
• Diarrhea
• Blurred vision or weakness.

Signs of excess parasympathetic activation:

• Salivation
• Sweating
• Lacrimation
• Slow pulse
• Small pupils
• Convulsions
• Muscle weakness/twitching
• Paralysis and loss of bladder control
• Pulmonary oedema
• Respiratory depression



  • Non-pharmacological

    • Remove poison by irrigating eye or washing skin (if in eye or on skin).
    • Give activated charcoal if ingested and within 1 hour of the ingestion.
    • Do not induce vomiting because most pesticides are in petrol-based solvents.
    • In a serious ingestion where activated charcoal cannot be given, consider careful aspiration of stomach contents by NG tube (the airway should be protected).
    • Auscultate the chest for signs of respiratory secretions and monitor respiratory rate, heart rate and coma score (if appropriate)
    • Give oxygen if oxygen saturation is less than 90%
  • Pharmacological

    If there are signs of excess parasympathetic activation (see above) give:

    Atropine, boluses of 5mg IV

    o Repeat every 10minutes until satisfactory atropinization (i.e. no chest signs of secretions, HR>80b/min, Systolic BP >80mmHg, pupils no longer pinpoint, Dry axillae)
    o Paediatric patient can start at 0.05mg/kg, then double the dose every five minutes, stop doubling the dose when parameters have improved
    Obidoxime (a cholinestarase activator) 5mg/kg IV if <24 hours. It may be given 5minutes after the first dose of atropine, if available.

    If muscle weakness gives:

    Pralidoxime (cholinesterase reactivator) 50mg/kg diluted with 15 ml water for injection by IV infusion over 30 minutes

    o Repeated once to twice
    o Followed by 10–20 mg/kg/hour, as necessary.


Educate the patient on Dos and Don’ts of poisoning prevention.


• Keep medicines and poison in proper containers and out of reach of children
• Use containers with child resistant caps
• Keep all products in their original container
• Read medicine labels carefully to avoid mistake


• Leave container open
• Transfer products from their origin
• Remove labels from the medicine products
• Put tablets into another containers such as purse or envelope
• Medicine/tablets as sweet
• Take your medicine in front of children as they often copy

Updated on,

14 Novemba 2020 15:02:13


    1. STG
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