classification of pesticides,clinical manifestations,diagnosis,treatment.

1. PESTICIDAL
POISONING
BY
CH.SAMPATH KUMAR
PHARM D 4TH YEAR

2. PESTICIDES
 A pesticide is a substance or mixture
of substance intended for preventing,
destroying, repelling or lessening
the damage caused by the pest.
 A pesticide can be a insect, plant
pathogen, weed, bacteria, bird etc. That compete with the
human for food, destroy property, spread disease.
 A pesticide can be a chemical, biological agent,
antimicrobial, disinfectant etc.
 Many chemical pesticides are poisonous to
human and animals.

3. PESTICIDES

4. Classification of pesticides
1. Herbicide-These are the chemicals used to kill weeds
(i.e., unwanted plants) e.g. paraquat,diquat
2. Insecticide-These are used to kill insects. E.g.
orghanophosphates,carbamates,pyrethroids.
3. Rodenticide-These are used to kill rodents. e.g.
anticoagulants,zinc,phosphorous
4. Nematicide-These are used to kill nematodes(worms)
e.g. ethylene dibromide
5. Molluscicide-These ar used to kill molluscs such as
snails &slugs e.g metaldehyde

5. 6.Fungicides-These are used to kill fungus e.g.
captan,sodium azide
7.Acaricides :compounds which kill mites,ticks &spiders
e.g. Azobenzene,chlorbenzilate
8.Miscellaneous pesticides: Hydrogen cyanide

6. Possible Health Effects

7. • Endocrine Damage- thyroid, hormonal,
reproductive, and metabolism
• Cancers
• Nervous System Damage
• Liver Damage
• Irritation to Skin and Eyes
• Vomiting, diarrhea, slow heart rate
• Birth Defects
Most health risks are associated with farm workers or
improper use although many studies have been done
that support endocrine damage to children from
exposure to pesticides in food.

8. How do Pesticides Affect the
Environment?
• Approx. 67 million birds die each year from
pesticides in the air
• Hundreds of fish die each year due to
pesticide run-offs in the water
• Pesticides can……..
• Kill wildlife due to posing
• Cause reproductive, developmental, and
behavioral problems

9. Facts About Pesticides
• At least three million people are
poisoned by pesticides every year.
• 25 million agricultural workers are
poisoned every year.
• More than 200,000 people die each
year from pesticides
• Half of all pesticides are used on the
five main crops- cereals, corn/maize,
rice, cotton and soya.

10. ORGANOPHOSPHATE
POISONING

11. Introduction:
• Organophosphate (OP) compounds are a diverse group
of chemicals used in both domestic and industrial
settings.
• Examples of organophosphates include insecticides
(malathion, parathion, dichlorvos, and diazinon)
• Worldwide mortality studies report mortality rates from
3-25 %
• Mortality rates depend on the type of compound used,
amount ingested, general health of the patient, delay in
discovery and transport, insufficient respiratory
management, delay in intubation, and failure in weaning
off ventilatory support.

12. Organophosphate(insecticide)
organophosphate poisoning accounts for nearly one third of
hospital admissions from poisoning in Sri Lanka.
Commonly using trades are follows.
Malathion, parathion, diazinon, fenthione, chlorpyrifos.
Action
inhibit acetylcholine esterase enzyme
at nerve endings by phosphorylation
acetylcholine at receptor sites
clinical features
depends on route of entry
ingestion inhalation eye contact

13. Route of entry:

14. Inhalation
• Cough
• Difficulty in breathing
• Bronchitis
• Pneumonia
Eye contact
• Irritation
• Pain
• Lacrimation
• Miosis
• Blurring vision
• Photophobia

15. Mnemonic for muscarinic signs &
symptoms:
• S – Salivation D – Diaphoresis
& diarrhoea
• L- Lacrimation U - Urination
• U – Urinary incontinence M - Miosis
• D – Diarrhoea + diaphoresis B –
Bradycardia, bronchospasm
• G – GI upset E – Excess
• E –Emesis L – Lacrimation
&
S - Salivation

16. CLINICAL FEATURES-
Muscarinic Nicotinic Central receptors
Cardiovascular
Bradycardia
Hypotension
Respiratory
Rhinorrhea
Bronchorrhea/spasm
Cough
Gastrointestinal
Increased salivation
Nausea/vomiting
Abdominal pain
Diarrhoea
Fecal incontinence
Genitourinary
Urinary incontinence
Ocular
Blurred vision/miosis
Increased lacrimation
Cardiovascular
Tachycardia
Hypertension
Musculoskeletal
Weakness
Fasciculations
Cramps
Paralysis
Anxiety
Restlessness
Ataxia
Convulsions
Insomnia
Dysarthria
Tremors
Coma
Absent reflexes
CS respiration
Resp. depression
Circulatory collapse

17. GASTRIC LAVAGE ACTIVATED CHARCOAL
OROPHARYNGEAL AIRWAY USED AMBU VENTILATION & ET TUBE

19. Investigations
ECG
Oxygen saturation
Blood gas analysis
Renal and hepatic function
Electrolytes
Glucose
Amylase
Urine toxicology

20. Grading of severity of poisoning
Biochemical Grading:
Red cell cholinesterase activity (% normal)
Grade
• 20-50%
Mild
• 10-20%
Moderate
• <10%
Severe

22. Management of OP Poisoning
Hospitalization/ ICU
1. Initial stabilization
2. Reduction of exposure
3. Administration of specific
antidote
4. Supportive treatment

23. Management-ABCD
• Airway - ensure clear airway, clear
secretions, check for cough/gag
• Breathing - check oxygenation,
supplemental O2, breathing pattern &
adequacy
• Circulation - heart rate, rhythm, blood
pressure
• Decontamination – gut and skin

24. Initial Stabilization of the patient
• Clear airway and
• Adequate ventilation because the
patient with acute
organophosphate poisoning (ACC)
commonly presents with
respiratory distress.
• Oxygen- Circulation- iv access

25. Decontamination
• Dermal spills—wash pesticide spills from the
patient
with soap and water and remove and discard
contaminated clothes, shoes and any other
material made from leather
• Gastric lavage—consider for presentations within
1 or 2 hours, when the airway is protected. A
single aspiration of the gastric contents may be as
useful as lavage
• Activated charcoal —50 g may be given orally or
nasogastrically to patients who are cooperative or
intubated, particularly if they are admitted within
one or two hours or have severe toxicity

26. Antidotes in the treatment of OP
poisoning
• Atropine- Reverses the muscarinic
features.
• Oxime- Reactivate
cholinesterase and reverses the
nicotinic features.

27. Atropine
• Initial dose: 0.5-2 mg IV every 5-10min until
atropinization
• Continuous infusion (8mg atropine in 100ml
NS) at rate of 0.02-0.08mg/kg/hr (0.25-1.0
ml/kg/hr) with additional 1-5mg bolus
• May require about 40-1500mg/day
• For at least 5-7days
• Watch out for OVER ATROPINIZATION

28. Pralidoxime
• An oxime that reactivates phosphorylated
cholinesterase
• Effects: skeletal-neuromuscular junctions (counteracts
weakness, fasciculation and respiratory depression)
• Administration within 48 hours of poison ingestion
• IV 1-2gm in 100cc of NS over 30min (at a rate not
exceeding 200mg/min), repeat in 1 hour if muscle
weakness persist, then at 8-12 hours interval if
cholinergic signs recur
• Severe case: IV infusion 500mg/hr (max 12gm in
24hours)
• Started after maximal atropinization

29. OXIMES IN OP POISONING

30. Other Treatments under investigation
• Magnesium
• Reduces acetylcholine release
• Blockage pre-synaptic calcium channels
• Limited human studies
• Clonidine
• Decrease the presynaptic synthesis and release of
acetylcholine.
• Central nervous system > peripheral cholinergic synapses
• Diazepam
• Diazepam reduces respiratory failure and cognitive deficit
• Postulate “uncoordinated stimulation of the respiratory
centres decreases phrenic nerve output”.

31. Thank
you