Group 9

Question 1

What is flumazenil used for?

Answer 1

• Reversing benzodiazepine sedation post-surgery.
• Treating benzodiazepine overdose (e.g., midazolam, diazepam).
• Diagnostic tool for benzodiazepine-induced altered mental status.

Question 2

What is the adult dosing regimen for reversing benzodiazepine sedation?

Answer 2

• Initial dose: 0.2 mg IV over 15 seconds.
• Repeat: 0.2 mg every minute.
• Max total dose: 1 mg.

Question 3

Why is flumazenil contraindicated in patients with tricyclic antidepressant (TCA) overdose?

Answer 3

Risk of seizures due to lowered seizure threshold.

Question 4

What are relative contraindications for flumazenil?

Answer 4

Chronic benzodiazepine use, epilepsy, hepatic impairment, and pregnancy (Category C).

Question 5

What is dimercaprol’s mechanism of action?

Answer 5

Binds heavy metals (e.g., arsenic, mercury) via sulfhydryl (-SH) groups, forming non-toxic complexes excreted in urine.

Question 6

What is the standard dosing regimen for arsenic poisoning?

Answer 6

3–5 mg/kg IM every 4 hours until urinary arsenic <50 mcg/24 hrs (duration: 7–10 days).

Question 7

What is the standard dosing regimen for arsenic poisoning?

Answer 7

3–5 mg/kg IM every 4 hours until urinary arsenic <50 mcg/24 hrs (duration: 7–10 days).

Question 8

How long does flumazenil’s effect last, and what risk does this pose?

Answer 8

30–60 minutes; risk of re-sedation requiring repeat doses.

Question 9

Why is dimercaprol stored in amber-colored ampoules?

Answer 9

To prevent oxidation of the drug.

Question 10

What are contraindications for dimercaprol?

Answer 10

Peanut allergy (due to peanut oil solvent), iron/cadmium poisoning, pregnancy (Category C).

Question 11

How is dimercaprol administered, and why not intravenously?

Answer 11

Deep IM only; IV administration risks toxicity due to the oily formulation.

Question 12

Classify herbicides by chemical structure and provide examples.

Answer 12

1. Phenoxy acids: 2,4-D.
2. Bipyridyls: Paraquat.
3. Triazines: Atrazine.
4. Glycine derivatives: Glyphosate.

Question 13

What is Paraquat’s mechanism of toxicity?

Answer 13

Induces oxidative stress via redox cycling → pulmonary fibrosis.

Question 14

How does Glyphosate toxicity primarily occur in humans?

Answer 14

Due to surfactants in formulations causing mitochondrial dysfunction and cardiotoxicity.

Question 15

How is Paraquat poisoning managed?

Answer 15

• Avoid supplemental oxygen (unless hypoxic).
• Consider hemoperfusion in severe cases.

Question 16

What is the primary route of absorption for herbicides?

Answer 16

Ingestion, though dermal and inhalational exposure are also significant

Question 17

What herbicide acts as a mitochondrial uncoupler?

Answer 17

2,4-D, causing neuromuscular and gastrointestinal disturbances.

Question 18

Why is urinary alkalinization used in 2,4-D poisoning?

Answer 18

Enhances renal excretion of the herbicide.

Question 19

What is a key diagnostic tool for herbicide-induced pulmonary toxicity?

Answer 19

Chest radiography to assess lung damage (e.g., Paraquat fibrosis).

Question 20

What is a major risk of chronic herbicide exposure?

Answer 20

Carcinogenesis, endocrine disruption, and neurodegenerative disorders.

Question 21

What is the max single pediatric dose of flumazenil?

Answer 21

0.2 mg IV, with a max total dose of 1 mg.

Question 22

What is the peak effect time of flumazenil after administration?

Answer 22

6–10 minutes, with effects lasting 30–60 minutes.

Question 23

Why is flumazenil stored in airtight containers?

Answer 23

To maintain stability and prevent degradation.

Question 24

What is the alternative dosing regimen for dimercaprol after the first two days of arsenic poisoning?

Answer 24

• Days 3–4: 2.5–3 mg/kg IM every 6 hours.
• Week 2: 2.5–3 mg/kg IM every 12 hours.

Question 25

Why is dimercaprol **ineffective for cobalt-induced cardiomyopathy**?

Answer 25

It does not address cardiac-specific toxicity from cobalt; limited evidence for efficacy.

Question 26

What precaution is needed for dimercaprol in patients with **hypertension or G6PD deficiency**?

Answer 26

May exacerbate hypertension or trigger hemolysis in G6PD-deficient individuals.

Question 27

Classify herbicides by **mode of action** with examples.

Answer 27

- **Photosynthesis inhibitors:** Atrazine (blocks photosystem II). - **Growth regulators:** 2,4-D (mimics plant hormones). - **Cell membrane disruptors:** Paraquat (generates free radicals).

Question 28

How does **enterohepatic recirculation** affect herbicide excretion?

Answer 28

Prolongs toxicity by reabsorbing unmetabolized compounds (e.g., some phenoxy acids).

Question 29

What **chronic effects** are linked to herbicide exposure?

Answer 29

**Carcinogenesis** (e.g., non-Hodgkin lymphoma), **endocrine disruption**, and **neurodegenerative disorders**.

Question 30

What **lab tests** are critical for herbicide poisoning diagnosis?

Answer 30

CBC, renal/liver function tests, and **urinary arsenic levels** (for dimercaprol monitoring).

Question 31

What **imaging** is used for suspected paraquat toxicity?

Answer 31

**Chest radiography** to detect pulmonary fibrosis or edema.

Question 32

What is the role of **activated charcoal** in acute herbicide ingestion?

Answer 32

Limits absorption if administered within **1–2 hours post-ingestion**.