Deprescribing Principles — MCQs
A patient given digoxin started having side effects like nausea and vomiting. The serum concentration of digoxin was 4 ng/mL. The plasma therapeutic range is 1-2 ng/mL. If the half-life of digoxin is 40 hours, how long should one wait before resuming the treatment?
Caution is taken while doing Inter-maxillary Fixation (IMF) for which of these types of patients?
Which of the following is the most appropriate treatment for an overactive bladder in a patient with dementia?
A patient does not understand the meaning of the doctor's words. What type of barrier does this represent?
Which study design is most effective for investigating rare adverse effects of a drug?
Continued suppression of bacterial growth after antibiotic levels have fallen below the Minimum Inhibitory Concentration (MIC) is known as?
Which of the following cannula is used in patient with severe dehydration and diarrhea?
Which of the following best describes a Type B adverse drug reaction?
Cisapride was withdrawn from the market due to?
What is the effect of indomethacin on the ductus arteriosus?
Deprescribing Principles Indian Medical PG Practice Questions and MCQs
Question 1: A patient given digoxin started having side effects like nausea and vomiting. The serum concentration of digoxin was 4 ng/mL. The plasma therapeutic range is 1-2 ng/mL. If the half-life of digoxin is 40 hours, how long should one wait before resuming the treatment?
- A. 120 hours
- B. 140-180 hours
- C. 1 half-life (40 hours)
- D. 80 hours (Correct Answer)
Explanation: ***80 hours (2 half-lives)***- Current digoxin level is **4 ng/mL**, which is **twice the upper therapeutic limit** (2 ng/mL), causing toxicity with nausea and vomiting [1]- After **1 half-life (40 hours)**: concentration reduces to 2 ng/mL (upper therapeutic limit) [2]- After **2 half-lives (80 hours)**: concentration reduces to 1 ng/mL (mid-therapeutic range) [2]- **Clinical rationale**: While 2 ng/mL is technically within range, waiting for 2 half-lives ensures the level is comfortably in the **middle of the therapeutic window** (1 ng/mL), providing a **safer margin** before resuming treatment in a patient who just experienced toxicity- This conservative approach minimizes risk of recurrent toxicity, especially important given the patient's recent symptoms at 4 ng/mL*1 half-life (40 hours)*- After 1 half-life, digoxin level would be 2 ng/mL, which is at the **upper limit** of the therapeutic range- While technically within the therapeutic range, this leaves **minimal safety margin** in a patient who just experienced toxicity- Starting treatment immediately at this level carries higher risk of recurrent side effects*120 hours (3 half-lives)*- After 3 half-lives, the concentration would be **0.5 ng/mL**, which is **below the therapeutic range** (1-2 ng/mL)- This is overly conservative and would **unnecessarily delay** resumption of essential cardiac medication- Could lead to inadequate control of the underlying condition (heart failure or atrial fibrillation)*140-180 hours (3.5-4.5 half-lives)*- This would reduce digoxin to **0.25-0.35 ng/mL**, well below therapeutic levels- This **excessive delay** is not clinically justified and could worsen the patient's cardiac condition- No standard protocol recommends waiting this long before resuming digoxin therapy
Question 2: Caution is taken while doing Inter-maxillary Fixation (IMF) for which of these types of patients?
- A. Psychiatric disorders
- B. All of the options (Correct Answer)
- C. Substance abusers
- D. Epileptics
Explanation: ***All of the options*** - All of these patient groups require extra caution during IMF due to potential complications during the period of jaw immobilization. - For patients with **psychiatric disorders**, **substance abuse**, or **epilepsy**, the risks associated with IMF often outweigh the benefits, necessitating careful assessment and alternative treatment strategies. *Psychiatric disorders* - Patients with psychiatric disorders may have difficulty tolerating the **entrapment** feeling of IMF. - They also have a higher risk of **non-compliance** and may attempt to remove the fixation. *Substance abusers* - **Vomiting** is common in substance abusers, which can lead to **aspiration** if the jaw is wired shut. - These patients may also be **non-compliant** with post-operative care instructions, jeopardizing treatment outcomes. *Epileptics* - **Seizures** during IMF can lead to serious complications, including **aspiration** if vomiting occurs. - The forceful jaw movements during a seizure can also cause **fracture of the teeth** or damage to already **repaired jaw bones**.
Question 3: Which of the following is the most appropriate treatment for an overactive bladder in a patient with dementia?
- A. Tolterodine (Correct Answer)
- B. Mirabegron
- C. Behavioral therapy/bladder training
- D. Oxybutynin
- E. Trospium
Explanation: ***Tolterodine*** - **Tolterodine** is a **muscarinic antagonist** that blocks acetylcholine receptors in the bladder, reducing detrusor muscle contractions and overactive bladder symptoms. - Unlike some other anticholinergics like oxybutynin, it has a **lower propensity to cross the blood-brain barrier** and thus a reduced risk of exacerbating cognitive impairment in patients with dementia. *Mirabegron* - **Mirabegron** is a **beta-3 adrenergic agonist** that relaxes the detrusor muscle, increasing bladder capacity. - While it has a different mechanism of action and is less likely to cause anticholinergic cognitive side effects than older anticholinergics, it can still cause **hypertension** and **tachycardia**, which may be problematic in elderly patients with comorbidities. *Behavioral therapy/bladder training* - **Behavioral therapy** and **bladder training** are important first-line treatments for overactive bladder. - However, for patients with **dementia**, cognitive impairment often makes adherence to and understanding of these complex therapies challenging or impossible without significant caregiver support. *Oxybutynin* - **Oxybutynin** is an **anticholinergic drug** that is effective for overactive bladder. - However, it has a **high affinity for muscarinic receptors** in the brain and readily crosses the blood-brain barrier, significantly increasing the risk of **cognitive impairment, confusion, and delirium** in elderly patients, especially those with pre-existing dementia. *Trospium* - **Trospium** is a **quaternary amine anticholinergic** that is hydrophilic and has minimal blood-brain barrier penetration. - While theoretically safer than oxybutynin in terms of CNS effects, it has **lower bladder selectivity** compared to tolterodine and may cause more peripheral anticholinergic side effects (dry mouth, constipation).
Question 4: A patient does not understand the meaning of the doctor's words. What type of barrier does this represent?
- A. Cultural
- B. Linguistic (Correct Answer)
- C. Psychological
- D. Environmental
- E. Physical
Explanation: ***Linguistic*** - This barrier occurs when there is a **lack of shared language** or when an individual does not understand the specific **vocabulary or jargon** being used. - In a medical context, this often manifests as a patient not understanding complex medical terms or explanations. *Cultural* - This barrier arises from differences in **beliefs, values, customs, or social norms** between individuals. - It would involve misunderstandings based on cultural perspectives rather than the literal meaning of words themselves. *Psychological* - This type of barrier relates to the emotional or mental state of the individuals involved, such as **anxiety, fear, or a lack of attention**. - While emotional factors can affect understanding, the core issue described here is specifically about the comprehension of words. *Environmental* - This barrier refers to **physical distractions or unsuitable surroundings** that hinder effective communication. - Examples include noise, inadequate privacy, or uncomfortable settings, which are not suggested by the patient's inability to understand the doctor's words. *Physical* - This barrier involves **sensory impairments** such as hearing loss, visual deficits, or speech difficulties. - While physical impairments can affect communication, the scenario describes comprehension of word meaning rather than sensory limitations.
Question 5: Which study design is most effective for investigating rare adverse effects of a drug?
- A. Cohort study
- B. Cross-sectional study
- C. Case-control study (Correct Answer)
- D. Clinical trial/experimental study
Explanation: ***Case-control study*** - This design starts by identifying individuals with the **rare adverse effect (cases)** and a control group without the effect to look back for exposure to the drug. - It is efficient for studying rare outcomes because it doesn't require following a large population for a long time to observe few events. *Cohort study* - A **cohort study** follows a group of individuals exposed and unexposed to a drug forward in time to observe outcomes. - While good for common outcomes, it would require an **extremely large sample size** and a long follow-up period to observe rare adverse drug effects. *Cross-sectional study* - A **cross-sectional study** assesses exposure and outcome simultaneously at a single point in time. - This design is suitable for determining **prevalence** but cannot establish temporal relationships between drug exposure and rare adverse effects, nor is it efficient for rare outcomes. *Clinical trial/experimental study* - **Clinical trials** are primarily designed to test the efficacy and safety of new interventions, usually focusing on common adverse effects. - They are generally **not powered** or long enough to detect rare adverse events, as such events would occur in very few participants, if any.
Question 6: Continued suppression of bacterial growth after antibiotic levels have fallen below the Minimum Inhibitory Concentration (MIC) is known as?
- A. Time dependent killing
- B. Sequential blockade
- C. Concentration dependent killing
- D. Post antibiotic effect (Correct Answer)
Explanation: ***Post antibiotic effect*** - The **post-antibiotic effect (PAE)** refers to the continued suppression of bacterial growth after antibiotic levels have fallen below the **Minimum Inhibitory Concentration (MIC)**. - This phenomenon allows for less frequent dosing while maintaining efficacy, which is important for drug scheduling. *Time dependent killing* - **Time-dependent killing** means that the duration for which the antibiotic concentration stays above the **MIC** is the most important factor for efficacy, not necessarily the peak concentration. - Antibiotics with this characteristic, such as **beta-lactams**, often require frequent dosing or continuous infusion. *Sequential blockade* - **Sequential blockade** occurs when two drugs act on consecutive steps in a metabolic pathway, leading to a synergistic effect that results in enhanced microbial killing. - A classic example is the combination of **sulfamethoxazole and trimethoprim**, which inhibit different enzymes in the folic acid synthesis pathway. *Concentration dependent killing* - **Concentration-dependent killing** indicates that the rate and extent of bacterial killing increase as the antibiotic concentration rises, particularly when it exceeds the **MIC**. - Antibiotics like **aminoglycosides** exhibit this effect, often benefiting from high peak concentrations to maximize efficacy.
Question 7: Which of the following cannula is used in patient with severe dehydration and diarrhea?
- A. Pink
- B. Grey (Correct Answer)
- C. Green
- D. Blue
Explanation: A **16-gauge (Grey)** cannula allows for a high flow rate, making it ideal for rapid fluid resuscitation in severely dehydrated patients [1]. This size is crucial for quickly restoring intravascular volume in cases of severe dehydration and diarrhea where large amounts of fluid are lost. [2] A **20-gauge (Pink)** cannula offers a moderate flow rate, suitable for routine intravenous fluid administration or medication delivery, but generally too slow for rapid resuscitation in severe dehydration. An **18-gauge (Green)** cannula provides a good flow rate, making it suitable for blood transfusions or moderate fluid resuscitation. A **22-gauge (Blue)** cannula has a slow flow rate, typically used for pediatric patients, elderly patients with fragile veins, or for maintaining venous access for medication administration.
Question 8: Which of the following best describes a Type B adverse drug reaction?
- A. Augmented effect of drug
- B. Effect seen on chronic use of drug
- C. Delayed effect of drug
- D. Unpredictable bizarre reaction (Correct Answer)
Explanation: ***Unpredictable bizarre reaction*** - Type B reactions are **unpredictable**, **bizarre**, and not directly related to the drug's known pharmacological actions. - They often involve **immunological reactions** or genetic predispositions, such as allergies or idiosyncratic responses. *Augmented effect of drug* - This describes a **Type A** adverse drug reaction, which is predictable and results from an **exaggerated pharmacological effect** of the drug. - It is typically dose-dependent and can be managed by adjusting the dosage. *Effect seen on chronic use of drug* - This description can apply to several types of adverse reactions, but it commonly relates to **Type C (chronic) reactions**, where effects occur only after prolonged exposure. - These reactions might be due to **cumulative toxicity** or adaptive changes in the body. *Delayed effect of drug* - This aligns with **Type D (delayed) adverse drug reactions**, which manifest long after the drug exposure has ended or after a period of latency. - Examples include **carcinogenesis** or teratogenesis, occurring months or years later.
Question 9: Cisapride was withdrawn from the market due to?
- A. QT Prolongation (Correct Answer)
- B. Hepatotoxicity
- C. Nephrotoxicity
- D. PR interval prolongation
Explanation: ***QT Prolongation*** - Cisapride was withdrawn from the market primarily due to its association with **dose-dependent QT interval prolongation**, which increased the risk of serious ventricular arrhythmias. - This **QT prolongation** could lead to potentially fatal **Torsades de Pointes**, a polymorphic ventricular tachycardia. *PR interval prolongation* - While some medications can affect the PR interval, **cisapride's primary cardiac concern** was specifically related to the QT interval, not the PR interval. - PR interval changes generally indicate issues with **AV nodal conduction**, a different mechanism than that affected by cisapride. *Hepatotoxicity* - Although drug-induced liver injury is a known adverse effect for many medications, **hepatotoxicity was not the primary reason** for cisapride's withdrawal. - The most significant and life-threatening adverse effect was its impact on cardiac repolarization. *Nephrotoxicity* - **Nephrotoxicity (kidney damage)** was not identified as a major or significant adverse effect associated with cisapride that led to its market withdrawal. - The drug's safety profile concerns were focused on its cardiovascular effects.
Question 10: What is the effect of indomethacin on the ductus arteriosus?
- A. Closure of the ductus in premature neonates (Correct Answer)
- B. Patent ductus arteriosus
- C. Closure of the ductus in term and premature neonates
- D. Closure of the ductus in older children
Explanation: **Explanation:** **Mechanism of Action:** The patency of the ductus arteriosus (DA) in utero is maintained by high levels of circulating **Prostaglandin E2 (PGE2)**, which acts as a potent vasodilator. **Indomethacin** is a non-selective Cyclooxygenase (COX) inhibitor. By inhibiting the COX enzyme, it decreases the synthesis of PGE2, leading to the constriction and subsequent functional **closure of the ductus arteriosus.** **Why Option A is Correct:** Indomethacin is specifically effective in **premature neonates** because their ductal tissue is highly sensitive to prostaglandin levels. In these infants, the ductus often fails to close spontaneously due to hypoxia or immature lungs, and pharmacological intervention can prevent the need for surgical ligation. **Analysis of Incorrect Options:** * **Option B:** This describes the pathology itself. Indomethacin is the *treatment* for Patent Ductus Arteriosus (PDA), not the cause. * **Option C:** Indomethacin is generally **ineffective in term neonates**. In full-term infants, the ductal smooth muscle is more developed and less dependent on prostaglandins for patency; closure is primarily driven by the postnatal rise in oxygen tension. * **Option D:** In older children, the ductus has typically undergone anatomical remodeling (fibrosis into the ligamentum arteriosum) or is too structurally fixed for prostaglandin inhibition to have any effect. **NEET-PG High-Yield Pearls:** * **Drug of Choice:** While Indomethacin was the traditional gold standard, **Ibuprofen (IV)** is now often preferred due to a lower risk of renal toxicity and necrotizing enterocolitis (NEC). * **Alternative:** **Paracetamol (Acetaminophen)** is an emerging alternative for PDA closure with a superior safety profile. * **Opposite Effect:** If a neonate has a cyanotic heart defect (e.g., Transposition of Great Arteries), we want to keep the ductus open. The drug used for this is **Alprostadil (PGE1 analog)**.
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