Management of Drug Poisoning — MCQs
Which of the following is the recommended treatment for iron poisoning in a 4-year-old child?
Diazepam poisoning is treated by:
Gastric lavage is contraindicated in the following:
All are features of organophosphorus poisoning, except:
What is the treatment of choice for Lalita, a 26-year-old female who accidentally took 100 tablets of paracetamol?
Alkaline diuresis in drug poisoning is not done in?
Ulipristal acetate (progesterone receptor modulator) should not be prescribed as emergency contraceptive in women with
Which drug is least likely to cause exanthematous skin eruptions?
Therapeutic drug monitoring is done for:
Which of the following anti-epileptic drugs has the highest teratogenic potential?
Management of Drug Poisoning Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is the recommended treatment for iron poisoning in a 4-year-old child?
- A. Blood transfusion
- B. Stomach lavage
- C. Observation and supportive care
- D. Deferoxamine IV at a dose of 15 mg/kg/hour (Correct Answer)
Explanation: ***Deferoxamine IV at a dose of 15 mg/kg/hour*** - **Deferoxamine** is a chelating agent specifically used to bind free iron, forming a complex that can be excreted renally. - An intravenous infusion at 15 mg/kg/hour is the recommended dose for severe iron poisoning, particularly when serum iron levels are high or symptoms indicate significant toxicity. *Stomach lavage* - **Stomach lavage** is generally not recommended for iron poisoning due to the risk of pushing iron tablets further into the intestine, potential for perforation, and limited efficacy in removing large, unabsorbed iron tablets. - Iron tablets are often **large** and **poorly soluble**, making lavage ineffective for complete removal. *Blood transfusion* - **Blood transfusion** is not a primary treatment for iron poisoning because iron toxicity is due to free iron in the body, not a deficiency that would be corrected by transfused blood. - It would only be considered in cases of severe anemia or significant blood loss, which are not direct treatments for iron overload. *Observation and supportive care* - While supportive care is crucial in managing complications of iron poisoning, **observation alone is insufficient** for moderate to severe cases of iron poisoning. - Significant iron overdose requires active intervention to prevent systemic toxicity, organ damage, and potentially fatal outcomes.
Question 2: Diazepam poisoning is treated by:
- A. Resins
- B. Hemofiltration
- C. Charcoal
- D. Flumazenil (Correct Answer)
Explanation: ***Flumazenil*** - **Flumazenil** is a **benzodiazepine receptor antagonist** that competitively binds to the benzodiazepine binding site on the GABA-A receptor, reversing the effects of diazepam. - It is used in cases of severe benzodiazepine overdose causing **respiratory depression** or **severe sedation**. *Resins* - **Resins**, such as **cholestyramine**, are typically used to bind toxins or drugs in the **gastrointestinal tract** that undergo enterohepatic recirculation. - They are generally not effective for reversing the central nervous system depression caused by a benzodiazepine overdose. *Hemofiltration* - **Hemofiltration** is a form of renal replacement therapy used to remove small and middle molecular weight substances from the blood. - While it can remove some drugs, **diazepam** is highly **lipophilic** and extensively **protein-bound**, making it poorly amenable to removal by hemofiltration. *Charcoal* - **Activated charcoal** is used to prevent the absorption of ingested toxins from the gastrointestinal tract. - It is effective when administered soon after ingestion but does not reverse the established effects of an absorbed drug like diazepam in an overdose situation.
Question 3: Gastric lavage is contraindicated in the following:
- A. Barbiturate poisoning
- B. Paracetamol poisoning
- C. Kerosene poisoning (Correct Answer)
- D. Carbolic acid poisoning
Explanation: ***Kerosene poisoning*** - Gastric lavage is contraindicated in **hydrocarbon poisoning** like kerosene due to the high risk of **aspiration pneumonitis**. [1] - Aspiration of hydrocarbons can lead to severe **chemical pneumonitis**, acute respiratory distress syndrome (ARDS), and even death. *Barbiturate poisoning* - Gastric lavage can be useful in **barbiturate poisoning**, especially if presenting within 1-2 hours of ingestion, to remove unabsorbed drug. - It's part of the management strategy to reduce drug absorption and potentially speed up recovery. *Paracetamol poisoning* - **Gastric lavage** may be considered in paracetamol overdose, particularly if performed within 1-2 hours of ingestion, to remove unabsorbed drug. - However, **activated charcoal** is usually the preferred method for gastric decontamination in paracetamol overdose, followed by **N-acetylcysteine**. *Carbolic acid poisoning* - While typically considered a corrosive, gastric lavage might be cautiously used in **carbolic acid (phenol) poisoning** in specific circumstances, such as very early presentation or large ingestions, but it carries risks of esophageal injury. [2] - Dilution with milk or water is often preferred, but lavage should be avoided if there's evidence of significant caustic injury or perforation risk.
Question 4: All are features of organophosphorus poisoning, except:
- A. Lacrimation
- B. Bradycardia
- C. Sweating
- D. Mydriasis (Correct Answer)
Explanation: ***Mydriasis*** - Organophosphorus poisoning leads to excessive **acetylcholine** activity, causing **miosis** (pinpoint pupils), not mydriasis. - Mydriasis would indicate **anticholinergic** effects, which are opposite to the symptoms of organophosphorus poisoning. *Lacrimation* - Excess **acetylcholine** stimulates **muscarinic receptors** in lacrimal glands, leading to excessive tear production. - This is a classic "SLUDGE" symptom (Salivation, Lacrimation, Urination, Defecation, Gastric upset, Emesis). *Bradycardia* - Increased **acetylcholine** activity at cardiac muscarinic receptors (M2 receptors) slows the heart rate, causing **bradycardia**. - This is a common and potentially dangerous cardiovascular effect of organophosphorus poisoning. *Sweating* - **Acetylcholine** acts on muscarinic receptors in secretory glands, including sweat glands, causing profuse **sweating**. - This is another characteristic cholinergic symptom due to widespread autonomic overstimulation.
Question 5: What is the treatment of choice for Lalita, a 26-year-old female who accidentally took 100 tablets of paracetamol?
- A. Acetyl cysteine (Correct Answer)
- B. Gastric lavage
- C. Hemodialysis
- D. Alkaline diuresis
Explanation: ***Acetyl cysteine*** - **Acetyl cysteine** is the **antidote** of choice for paracetamol (acetaminophen) overdose. - It works by replenishing **glutathione stores**, which are essential for detoxifying the toxic metabolite of paracetamol, **N-acetyl-p-benzoquinone imine (NAPQI)**. *Gastric lavage* - **Gastric lavage** is generally not recommended for paracetamol overdose unless performed within **1 hour** of ingestion, and even then, its effectiveness is limited. - It carries risks such as aspiration and esophageal injury, making it less favorable than activated charcoal. *Hemodialysis* - **Hemodialysis** is generally reserved for severe cases of paracetamol overdose with life-threatening complications like **severe metabolic acidosis** or **renal failure**, and when acetyl cysteine treatment is delayed or ineffective. - Paracetamol itself is dialyzable, but hemodialysis is not the primary treatment for uncomplicated overdose. *Alkaline diuresis* - **Alkaline diuresis** is a treatment used for overdoses of **weak acids**, such as salicylates or phenobarbital, to enhance their renal excretion. - Paracetamol is not a weak acid, so alkaline diuresis would not be effective in eliminating it from the body.
Question 6: Alkaline diuresis in drug poisoning is not done in?
- A. Aspirin
- B. Morphine (Correct Answer)
- C. Phenobarbitone
- D. Methotrexate
Explanation: ***Morphine*** - **Morphine** is an **alkaline drug**, so its elimination is actually enhanced by **acidification of the urine**, not alkalinization. - Alkaline diuresis would decrease the ionization of morphine in the renal tubules, leading to **increased reabsorption** and reduced excretion. *Aspirin* - **Aspirin (acetylsalicylic acid)** is an **acidic drug**, and **alkaline diuresis** is effective in increasing its excretion by trapping the ionized form in the renal tubules. - This process prevents reabsorption and promotes clearance, which is a standard treatment for aspirin overdose. *Methotrexate* - **Methotrexate** is a **weak organic acid**, and **alkaline diuresis** is crucial in reducing its toxicity, especially in high-dose therapy. - By increasing urine pH, the renal elimination of methotrexate is significantly enhanced, preventing kidney damage and systemic accumulation. *Phenobarbitone* - **Phenobarbitone** is a **weak acid**, and **alkaline diuresis** is a well-established method to increase its renal excretion in cases of overdose. - Alkalinization of the urine promotes the ionization of phenobarbitone, reducing its reabsorption by the renal tubules and accelerating its elimination.
Question 7: Ulipristal acetate (progesterone receptor modulator) should not be prescribed as emergency contraceptive in women with
- A. liver dysfunction (Correct Answer)
- B. glaucoma
- C. coagulopathy
- D. kidney failure
Explanation: ***Correct: liver dysfunction*** - **Ulipristal acetate** is extensively metabolized in the **liver** by the CYP450 enzyme system, predominantly CYP3A4. - In individuals with **severe hepatic impairment**, the metabolism of ulipristal acetate can be impaired, leading to increased plasma concentrations and potential adverse effects. - **Severe liver dysfunction** is a documented contraindication in product labeling. *Incorrect: glaucoma* - There is **no known contraindication** for ulipristal acetate use in individuals with **glaucoma**. - Its mechanism of action primarily involves progesterone receptors and does not directly impact intraocular pressure. *Incorrect: coagulopathy* - Ulipristal acetate does **not significantly affect blood coagulation** parameters or platelet function. - It is not contraindicated in individuals with **coagulopathy**, unlike some estrogen-containing contraceptives. *Incorrect: kidney failure* - While urinary excretion of ulipristal acetate metabolites occurs, the **primary elimination pathway is fecal** (approximately 90%). - **Kidney failure** is not considered a contraindication, and dose adjustments are generally not required.
Question 8: Which drug is least likely to cause exanthematous skin eruptions?
- A. Phenytoin
- B. Ampicillin
- C. Phenylbutazone
- D. Hydrocortisone (Correct Answer)
Explanation: ***Hydrocortisone*** - **Corticosteroids** like hydrocortisone are **anti-inflammatory** and immunosuppressive agents. - They are commonly used to **treat allergic reactions** and skin eruptions, making them highly unlikely to cause exanthematous eruptions themselves. *Phenytoin* - **Anticonvulsant** medications like phenytoin are frequently associated with various **drug-induced skin reactions**, including exanthematous eruptions. - It is a common cause of **drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome**, which manifests with a widespread rash. *Ampicillin* - **Antibiotics**, particularly **aminopenicillins** like ampicillin, are well-known triggers for **maculopapular rashes** and other exanthematous eruptions. - The incidence of ampicillin-induced rash is notably higher, especially in patients with **viral infections** like infectious mononucleosis. *Phenylbutazone* - This **non-steroidal anti-inflammatory drug (NSAID)** has a documented history of causing severe cutaneous adverse reactions, including **exanthematous eruptions**. - Due to its potential for serious side effects, such as **aplastic anemia** and severe skin reactions, its use is now highly restricted.
Question 9: Therapeutic drug monitoring is done for:
- A. Aspirin
- B. Heparin
- C. Phenytoin (Correct Answer)
- D. Metformin
Explanation: ***Phenytoin*** - **Phenytoin** has a **narrow therapeutic window**, meaning the difference between an effective and a toxic dose is small, necessitating close monitoring. - Its **variable absorption** and **nonlinear pharmacokinetics** (saturable metabolism) make individual dosing adjustments critical to maintain therapeutic levels and avoid toxicity. *Aspirin* - **Aspirin** is generally not monitored via plasma levels for its analgesic or antiplatelet effects, as its therapeutic effects are often observed at doses where plasma monitoring is not practical or necessary. - Its primary therapeutic use as an **antiplatelet agent** is evaluated by clinical outcomes rather than drug concentration. *Heparin* - **Heparin** is monitored using coagulation tests like **aPTT (activated partial thromboplastin time)** or anti-Xa levels to assess its anticoagulant effect, not direct drug concentration. - Therapeutic drug monitoring for heparin focuses on its **pharmacodynamic effects** on the clotting cascade rather than its absolute plasma concentration. *Metformin* - **Metformin** has a relatively **wide therapeutic index** and its efficacy is primarily measured by reductions in blood glucose and HbA1c, not by plasma drug concentrations. - It is excreted largely unchanged by the kidneys, and dose adjustments are typically made based on **renal function** and glycemic control.
Question 10: Which of the following anti-epileptic drugs has the highest teratogenic potential?
- A. Carbamazepine
- B. Phenytoin
- C. Valproate (Correct Answer)
- D. Lamotrigine
Explanation: ***Correct: Valproate*** - **Valproate has the highest teratogenic potential** among all anti-epileptic drugs, with a **10-20% risk of major congenital malformations** - **Neural tube defects** (spina bifida) occur in **1-2% of exposed pregnancies**, which is 10-20 times higher than the general population - Other significant risks include **cardiac malformations, craniofacial abnormalities**, and **neurodevelopmental disorders** (autism spectrum disorder, reduced IQ) - **Fetal valproate syndrome** is a recognized clinical entity - Current guidelines strongly recommend **avoiding valproate in women of childbearing potential** unless no alternatives exist *Incorrect: Carbamazepine* - Has teratogenic risks but significantly **lower than valproate** (2-5% risk of major malformations) - Associated with **neural tube defects** (0.5-1% risk, lower than valproate) - Considered a safer alternative when valproate must be avoided *Incorrect: Phenytoin* - Causes **fetal hydantoin syndrome** with characteristic features: craniofacial anomalies, nail/digital hypoplasia, growth restriction, and developmental delay - Teratogenic risk is **moderate** (approximately 5-10% risk of major malformations) - Risk is significant but **lower than valproate** *Incorrect: Lamotrigine* - Considered **one of the safest anti-epileptic drugs** during pregnancy - Low teratogenic risk with **major malformation rate of 2-3%** (close to baseline population risk) - Slight increased risk of **oral clefts** at higher doses - **Preferred choice** for women of childbearing potential requiring anti-epileptic therapy
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