Pesticides & Alkaloid

Question 1

Characters that make paraquat very toxic:

Answer 1

1. Rapidly acting
2. Rapidly distributed
   During 6 hours, it will be distributed in all body
   All cells will take it (non-selective)
3. No antidote

Question 2

Route of exposure of paraquat

Answer 2

Inhalation
Dermal
Ingestion (accidentally with high case facility)

Question 3

Paraquat compound that used in libya:

Answer 3

Gramaxone (yellowish color)
Weedol (granulation form)

Question 4

Mechanism of toxicity of paraquat:

Answer 4

1. Act on redox cycling:
   O2&raquo_space; superoxide radical&raquo_space; hydrogen peroxide (very harmful substances)&raquo_space;oxidative stress&raquo_space; cell death
2. Consume NADPH (antioxidant)
3. Secondary inflammatory response
4. Multi-organ failure, especially that consumes more O2 (alveolar cells, liver, heart, kodneys)

Question 5

Pharmacokinetics of paraquat

Answer 5

• Highly polar and corrosive
• ingestion > rapid absorption > rapid distributed.
• active transport by cell membrane.
• NO significant biotransformation.
• eliminated by kidneys … until destroying kidneys cells&raquo_space; no more elimination.

Question 6

Lethal dose of paraquat

Answer 6

1-4 grams

Question 7

Main target of paraquat:

Answer 7

Lungs : due to active, energy-dependent uptake by alveolar type I and type II (pulmonary fibrosis)

Question 8

Clinical manifestations of paraquat:

Answer 8

Phase 1 (GIT) : corrosive affect on GIT, pain in mouth and pharynx, there may be bloody vomiting and diarrhea.
Phase 2 (hepatic or renal phase) : Systemic effects on kidney and liver (manifest of renal and liver failure).
Phase 3 (respiratory phase):
Signs of respiratory illness (Cyanosis and Cough)

Question 9

Physical examination of paraquat toxicity:

Answer 9

• Mouth, pharynx: necrosis, ulceration, inflammation.
• Dehydration (vomiting)
• Progressive refractory hypotension
• Chest: tachypnic, dyspnic, crackles (alveolitis) spontaneous emphysema, and mediastinits.
Abdomen : diffuse tenderness.
Topical contact: dermatitis, corneal ulceration

Question 10

Investigation for paraquat toxicity:

Answer 10

• Serum electrolytes and RFT
• Blood gas :acidemia, respiratory acidosis, and metabolic acidosis.
• Chest radiograph : for assessing acute lung injury
• Specific testing: urine paraquat > cheap, based on color chage after adition of dithionite soln.
• Serum paraquat

Question 11

Management of paraquat toxicity:

Answer 11

• Supportive therapy
• Gastric lavage: with aqoues suspension of clay
• Careful O2 administration
• Repeated hemoperfusion
• Hemodialysis
• Antioxidant therapy: actylcyctein, sodium salicylate, deferoxamine, and Vit C E.

Question 12

What are the opioids:

Answer 12

A group of narcotic analgesics that represent one of the most important groups of CNS depressant.

Question 13

Definition of pesticides

Answer 13

Any substance used for killing any unwanted living.

Question 14

There are three major groups for pesticides

Answer 14

1. Insecticides like organophosphate.
2. Herbicides (paraquat)
3. Rodenticides (anticoagulant)

Question 15

Uses of organophosphate

Answer 15

1. Insecticide
2. pediculicide
3. War gases like sarin

Question 16

Mode of exposure of organophosphate

Answer 16

1. Dermal
2. Inhalation
3. Oral

Question 17

Mechanism of action of organophosphate

Answer 17

Inhibition of ACE enz by phosphorylation.
Fate of the enzyme
1. Hydrolysis
2. Irreversible process (aging)

Question 18

Clinical manifestation of the organophosphate poisoning

Answer 18

1. Acut syndrome.
2. Intermediate syndrome.
3. Organophosphate induced delayed polyneuropathy

Question 19

Treatment of organophosphate poisoning

Answer 19

1. ABC
2. GIT decontamination
3. Atropine
4. Oximes : the real antidote