Toxicity of Therapeutic Agents

Question 1

The incidence of aspirin poisoning in children declined due to:

Answer 1

1. The use of alternative antipyretics.
2. Repackaging, using CRC (child resistant containers)
3. Salicylates association with Reye’s syndrome

Question 2

Clinical features of aspirin poisoning:

Answer 2

1. CNS –> hearing, vertigo, delirium, seizure and cerebral edema
2. HEM –> bleeding tendency
3. GIT –> nosia , vomiting and hemorragic gastritis
4. • SIADH (Syndrome of inappropriate antidiuretic hormone secretion)

Question 3

Treatment of aspirin poisoning:

Answer 3

1. Sopportive Treatment
2. GIT decontamination
3. Urin alkalizatio and hemodialysis

Question 4

Chronic poisoning of aspirin

Answer 4

1. In elderly & infants
2. Severe dehydration
3. Altered mental state
4. Long time to diagnose
5. More dangerous (mortality 25% & morbidity 30%)
6. Serum concentration low (up to 30 mg/dl)

Question 5

Acute poisoning of aspirin

Answer 5

1. In adult
2. Mild dehydration
3. Normal mental state (initially)
4. Short time to diagnose
5. Less dangerous (mortality 2% morbidity 16%)
6. Serum concentration high (up to 40 mg/dl)

Question 6

The picture of salicylate poisoning

Answer 6

1. Elevated anion gap.
2. 1ry respiratory alkalosis.
3. 1ry metabolic acidosis.

Question 7

T/F: Normal anion gap exclude salicylate toxicity

Answer 7

False
Some patients with mixed acid-base disturbances have normal anion-gap metabolic acidosis

Question 8

Metabolic pathways of acetaminophen

Answer 8

1. Hepatic Conjugation
   - glucuronic
   - sulfate
2. Oxidation by cytochrome oxidase P450 –> NAPQI
3. Unchanged Excretion (5%)

Question 9

Which pathway is predominant in children and adult?

Answer 9

1. Children - sulfate conjugation
2. Adult - glucuronic conjugation.

Question 10

Manifistation of acetaminophen poisoning

Answer 10

Phase 1 (1d) –> n&v
Phase 2 (2d) –> pain and elevated transaminase
Phase 3 (4d) –> Jaundice, bleeding and encephalopathy
phase 4 (2w) –> recovery or death! 🎰🎲

Question 11

Treatment of acetaminophen poisoning

Answer 11

1. Gastric lavage (1h).
2. Active charcoal (not with antidote)
3. Antidote (N-acetyl cysteine)
   
   • oral (8h)
   • IV

Question 12

Investigations for acetaminophen poisoning

Answer 12

Serum level of
- acetaminophen
- transaminase
- creatinine

Question 13

In case of acetaminophen poisoning these levels indicate poor prognosis

Answer 13

1. Low pH < 7.3
2. Hepatic encephalopathy
3. Creatinine >300
4. Coagulation VIII/V > 30

Question 14

Manifistation of iron toxicity

Answer 14

Phase 1 (6h)
1. bleading & pain
2. Hypovolemia & shock
3. Convulsion & coma
Phase 2 (12h)
Appearent recovery
phase 3 (1d)
Remember aspirin
1. High anion gap
2. Metabolic acidosis
3. Coagulopathy
phase 4 (weeks)
1. Hepatic failure
2. Pyloric stenosis

Question 15

Treatment of iron poisoning

Answer 15

1. Sopportive Treatment
2. Antidot (Desferrioxamine)

Question 16

Infection common in case of iron toxicity

Answer 16

Yersinia enterocolitica