Insecticides

Question 1

2 components of insecticides are…

Answer 1

Organophosphates & Carbamate

Question 2

MOA of OPCs & Carbamates is…

Answer 2

Inhibits Acetylcholine esterase enzyme by binding to its active site whos normal function is to breakdown Ach to choline+acetate. So this means more Ach in synapse which increase acrivation of muscarinic and nicotinic receptors

Question 3

What are the symptoms of OPC & Carbamate mild poisoning?

Answer 3

Muscarinic: SLUDGE BBB (Salivation, lacrimation, urination, defecation, GI distress like nausea tenesmus, emesis, bronchoconstriction, bradycardia, bronchorrhea)

Nicotinic: CÑS stimulant effects (restlessness, insomnia, nightmares, headache, dizziness, anxiety)

Question 4

Route of entry of organophosphorus compunds is by…

Answer 4

Ingestion, inhalation and through skin

Question 5

Factors which determines speed and severity of poisoning include…

Answer 5

Rate of phosphorylation (inactivation) of AchE enzyme
Rate of hydrolysis of phosphorylated AchE and release of active AchE

Question 6

Difference between carbamates and organophosphates in terms of interaction with AchE is…

Answer 6

Carbamate hydrolyzed from AchE active site within 24hrs
Organophosphates undergo aging which causes irreversible inactivation of AchE

Question 7

What are the symptoms of carbamate and OP moderate poisoning?

Answer 7

Nicotinic: FMH (Fasiculation, muscle wasting, hypotonia) tremor, generalized fatigue, respiratory paralysis

Question 8

What are the symptoms of severe carbamate and OP poisoning?

Answer 8

Impaired consciousness
Pulmonary edema and cyanosis
Respiratory depression and asphyxia
Atrial fibrillation
Flacid paralysis

Question 9

Activity of acetylcholine esterase in severe poisoning is reduced to…

Answer 9

Less than 10%

Question 10

Gow do you diagnose insecticide poisoning?

Answer 10

Taking blood sample and measuring activity of AchE

Question 11

What is the management of insecticide poisoning?

Answer 11

Remove clothe and wash skin with soap and water
Gastric lavage
Remove respiratory secretions (bronchorrhea)
Replace fluid loss from emesis
Atropine (acts on muscarinic receptors)
Diazepam to reduce anxiety

Question 12

What is the antidote for insecticide poisoning

Answer 12

Pralidoxime : acts by binding to the phosphorus atom that phosphorylated (inactivated) the AchE, forming oxime-phosphate which breaks off from AchE, making the AchE active again

Question 13

Paraquat is a…

Answer 13

Herbicide

Question 14

Fatality of paraquat mostly due to…

Answer 14

Suicide

Question 15

Fatal dose of paraquat is…

Answer 15

4mg/dL (quat=quadra=4)

Question 16

Stages of paraquat poisoning…

Answer 16

Stage 1 (day 1-5): local corrosive action, hemoptysis, ulceration of mucous membrane, nausea, diarrhea, oliguria

Stage 2 (Day 2-8): Signs of liver, kidney, respiratory and cardiac damage

Stage 3 (day 3-14): Pulmonary fibrosis

Question 17

Treatment of paraquat poisoning by…

Answer 17

Fuller’s earth & activated charcoal
Increase elimination by hemodialysis
Modification of tissue toxicity with CDC (Cyclophosphamide, dexamethasone, chlorphenairamine) vit C and E

Question 18

Activity of AchE in mild and moderate poisoning is….

Answer 18

50%