Neonatal Pharmacology — MCQs
Which of the following drugs can cause ototoxicity?
Which of the following drugs can cause cartilage damage in children?
Newborns as compared to adults eliminate lidocaine:
A 70 kg man was given a drug with a dose of 100 mg/kg body weight, twice daily. The half-life (t1/2) is 10 hours, the plasma concentration is 1.9 mg/mL, and the clearance is unknown. What is the clearance of this drug?
A term neonate, with a birth weight of 2700 g, who is otherwise well, and is exclusively breastfed, presents for routine evaluation. His total serum bilirubin is found to be 14mg/dl on day 5. What is the management?
Neonatal tetanus prevention is best done by which antenatal measure?
A pediatrician was called for attending a new born baby in the labour ward. The serum unconjugated bilirubin of this baby was 33 mg/dL. Which of the following drug taken by mother in late 3rd trimester may have led to this problem?
A G2 P1 - 29-year-old female delivered a baby, but the baby died within 48 hours due to medical reasons. What drug will you advise to stop breast milk secretion?
What is the treatment of choice for a 5-year-old child with bedwetting?
Which calcium channel blocker has the shortest duration of action?
Neonatal Pharmacology Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following drugs can cause ototoxicity?
- A. Metronidazole
- B. Amoxicillin
- C. Ciprofloxacin
- D. Amikacin (Correct Answer)
Explanation: ***Amikacin*** - **Amikacin** is an **aminoglycoside antibiotic** and is **the most well-known** drug among the options for causing **ototoxicity** (damage to the ear, leading to hearing loss, tinnitus, or vestibular dysfunction) [1], [2]. - This adverse effect is **dose-dependent** and related to the **cumulative dose** and **peak plasma levels** of the drug [2]. - Aminoglycosides cause both **cochlear toxicity** (hearing loss) and **vestibular toxicity** (balance problems) [1], [2]. *Metronidazole* - **Metronidazole** is an antibiotic and antiprotozoal drug that primarily causes **gastrointestinal upset** and a **metallic taste** in the mouth. - While it can cause neurological side effects like **peripheral neuropathy**, **ototoxicity is not a typical adverse effect** associated with metronidazole. *Amoxicillin* - **Amoxicillin** is a common **penicillin-class antibiotic** generally considered safe with a good side effect profile. - Its most common side effects are **gastrointestinal disturbances** like nausea, vomiting, and diarrhea, as well as **allergic reactions** and skin rashes. - **Ototoxicity is not a recognized side effect** of beta-lactam antibiotics. *Ciprofloxacin* - **Ciprofloxacin** is a **fluoroquinolone antibiotic** primarily associated with side effects like **tendinopathy**, **arthropathy**, and **QT prolongation**. - While fluoroquinolones **can cause ototoxicity** (tinnitus, hearing disturbances), this is **much less common and less severe** compared to aminoglycosides. - Ciprofloxacin is not the primary drug associated with ototoxicity in this context.
Question 2: Which of the following drugs can cause cartilage damage in children?
- A. Cotrimoxazole and other sulfonamides
- B. Penicillin and other beta-lactams
- C. Metronidazole and other nitroimidazoles
- D. Ciprofloxacin and other fluoroquinolones (Correct Answer)
Explanation: ***Ciprofloxacin and other fluoroquinolones*** - Fluoroquinolones, including ciprofloxacin, are known to cause **arthropathy** (joint disease) and **cartilage damage** in growing children and adolescents [1]. - This adverse effect has limited their use in pediatric populations, typically reserved for severe infections where other effective and safer alternatives are unavailable [1]. *Cotrimoxazole and other sulfonamides* - Sulfonamides are primarily associated with adverse effects like **hypersensitivity reactions** (e.g., Stevens-Johnson syndrome), **bone marrow suppression**, and **crystalluria**. - They are not typically linked to cartilage damage in children. *Penicillin and other beta-lactams* - Penicillins and other beta-lactam antibiotics are generally considered **safe in children** and are a common choice for pediatric infections. - Their primary adverse effects are hypersensitivity reactions, such as **rashes** or **anaphylaxis**, and gastrointestinal disturbances, not cartilage damage. *Metronidazole and other nitroimidazoles* - Metronidazole's main adverse effects include **gastrointestinal upset**, **metallic taste**, and **neurological symptoms** (e.g., peripheral neuropathy, seizures with high doses). - There is no known association between metronidazole and cartilage damage in children.
Question 3: Newborns as compared to adults eliminate lidocaine:
- A. Variable
- B. More rapidly
- C. Equally fast
- D. More slowly (Correct Answer)
Explanation: ***More slowly*** - Newborns have **immature hepatic enzyme systems**, particularly for **CYP1A2** and **CYP3A4**, which are crucial for lidocaine metabolism. - Reduced **plasma protein binding** and a larger **volume of distribution** in newborns can also impact lidocaine clearance, leading to slower elimination. *Variable* - While there can be individual variability in drug metabolism, the general trend for lidocaine elimination in newborns is consistently slower due to physiological immaturity, not merely variable. - This option does not capture the overall physiological characteristic of drug elimination in neonates. *More rapidly* - This is incorrect because newborns have underdeveloped liver function and enzyme systems, which would hinder, not accelerate, the metabolism and elimination of drugs like lidocaine. - A more rapid elimination would suggest a highly efficient metabolic pathway, which is not the case in neonates. *Equally fast* - This is incorrect as the **pharmacokinetic profile** of drugs, including lidocaine, differs significantly between newborns and adults due to developmental differences in organ function (e.g., liver, kidneys). - The liver's metabolic capacity in newborns is not fully mature enough to eliminate lidocaine at the same rate as in adults.
Question 4: A 70 kg man was given a drug with a dose of 100 mg/kg body weight, twice daily. The half-life (t1/2) is 10 hours, the plasma concentration is 1.9 mg/mL, and the clearance is unknown. What is the clearance of this drug?
- A. 20 liter/hr
- B. K is 0.0693
- C. 0.22 L/hr (Correct Answer)
- D. 0.02 L/hr
Explanation: ***0.22 L/hr*** - To calculate clearance at steady state, we use the formula: **Clearance (Cl) = Dose Rate / Css** (steady-state plasma concentration). - **Dose rate calculation**: 100 mg/kg × 70 kg × 2 doses/day = 14,000 mg/day = 583.33 mg/hr - **Converting plasma concentration**: 1.9 mg/mL = 1900 mg/L - **Clearance calculation**: Cl = 583.33 mg/hr ÷ 1900 mg/L = **0.307 L/hr** - **Note**: The calculated value (0.307 L/hr) does not exactly match any option. The marked answer (0.22 L/hr) is the closest approximation among the given choices. This discrepancy may arise from rounding in the original question parameters or implicit assumptions about bioavailability/volume of distribution. *0.02 L/hr* - This value is approximately 15 times lower than the calculated clearance. - Such low clearance would result in much higher plasma concentrations or require significantly lower dosing. *20 liter/hr* - This clearance is approximately 65 times higher than calculated, representing an unrealistically high value for this scenario. - Such high clearance would result in very low plasma concentrations unless extremely high doses were administered. *K is 0.0693* - This represents the **elimination rate constant (k)**, calculated as k = 0.693/t1/2 = 0.693/10 hr = 0.0693 hr⁻¹. - While mathematically correct for k, the question specifically asks for **clearance**, not the elimination rate constant. - Clearance is related to k by: Cl = k × Vd (volume of distribution).
Question 5: A term neonate, with a birth weight of 2700 g, who is otherwise well, and is exclusively breastfed, presents for routine evaluation. His total serum bilirubin is found to be 14mg/dl on day 5. What is the management?
- A. No active treatment required (Correct Answer)
- B. Stop breastfeeding for 2 days
- C. Phototherapy
- D. Exchange transfusion
Explanation: ***No active treatment required*** - A total serum bilirubin of **14 mg/dL** on day 5 in an otherwise well, exclusively breastfed term neonate (birth weight 2700g, which is >2500g) falls within the **physiologic jaundice range** and below thresholds for intervention. - This level is considered **normal for breastfed infants** at this age and does not warrant medical intervention as per current guidelines. *Stop breastfeeding for 2 days* - This intervention, known as **breast milk jaundice interruption**, is usually reserved for higher bilirubin levels or if there is concern for significant breast milk jaundice, which is not indicated here. - Temporarily stopping breastfeeding can disrupt the establishment of breastfeeding and is generally discouraged unless strictly necessary. *Phototherapy* - **Phototherapy** is indicated for bilirubin levels typically >15-18 mg/dL in a healthy term neonate on day 5, depending on risk factors, which this infant does not meet. - It works by converting unconjugated bilirubin into water-soluble isomers that can be excreted more easily. *Exchange transfusion* - **Exchange transfusion** is reserved for severe hyperbilirubinemia, usually with bilirubin levels approaching or exceeding 20-25 mg/dL, especially if there are signs of **acute bilirubin encephalopathy**. - This level is far below the threshold for such an invasive procedure.
Question 6: Neonatal tetanus prevention is best done by which antenatal measure?
- A. Tetanus toxoid (Correct Answer)
- B. Tetanus immunoglobulin
- C. Antibiotics (e.g., Penicillin)
- D. Antibiotics (e.g., Metronidazole)
Explanation: ***Tetanus toxoid*** - **Tetanus toxoid vaccination** of pregnant women stimulates **active immunity** in the mother, leading to production of protective antibodies. - These maternal IgG antibodies cross the placenta and provide **passive immunity** to the fetus/neonate, protecting against neonatal tetanus. - Neonatal tetanus is often acquired through umbilical stump infection with *Clostridium tetani* spores in unhygienic delivery conditions. - **WHO recommends** at least 2 doses of TT during pregnancy for prevention of neonatal tetanus. *Tetanus immunoglobulin* - **Tetanus immunoglobulin (TIG)** provides immediate **passive immunity**, but its effect is short-lived (3-4 weeks). - It's used for **post-exposure prophylaxis** or treatment in individuals who are unimmunized or inadequately immunized. - Not practical or recommended for routine antenatal prevention due to short duration, high cost, and need for repeated administration. *Antibiotics (e.g., Penicillin)* - While penicillin can be used as part of **tetanus treatment** to kill *Clostridium tetani* bacteria, it does not provide **preventive immunity** to the fetus. - Antibiotics do not neutralize the tetanus toxin or provide antibodies for passive immunity. - They have no role in antenatal prevention of neonatal tetanus. *Antibiotics (e.g., Metronidazole)* - **Metronidazole** is another antibiotic used to treat *Clostridium tetani* infection. - Like penicillin, it does not confer **immunity** (active or passive) to the neonate. - Not an effective antenatal measure for preventing neonatal tetanus.
Question 7: A pediatrician was called for attending a new born baby in the labour ward. The serum unconjugated bilirubin of this baby was 33 mg/dL. Which of the following drug taken by mother in late 3rd trimester may have led to this problem?
- A. Ampicillin
- B. Azithromycin
- C. Cotrimoxazole (Correct Answer)
- D. Chloroquine
Explanation: ***Cotrimoxazole*** - **Cotrimoxazole** (trimethoprim-sulfamethoxazole) can displace **bilirubin** from albumin-binding sites in the newborn, leading to increased levels of **unconjugated bilirubin** and a higher risk of kernicterus. - Sulfonamides, a component of cotrimoxazole, are known to interfere with **bilirubin metabolism** and transport in neonates, particularly when taken by the mother late in pregnancy. *Ampicillin* - **Ampicillin** is a penicillin-class antibiotic generally considered safe during pregnancy and is not known to cause significant neonatal **hyperbilirubinemia**. - Its mechanism of action does not involve competition for **albumin-binding sites** with bilirubin. *Azithromycin* - **Azithromycin** is a macrolide antibiotic commonly used in pregnancy and does not have a recognized association with significant **unconjugated hyperbilirubinemia** in newborns. - It does not significantly affect the **bilirubin-albumin binding** in neonates. *Chloroquine* - **Chloroquine** is an antimalarial drug, and while generally avoided in the first trimester, it has not been linked to severe neonatal **hyperbilirubinemia** similar to that caused by sulfonamides. - Its primary **side effects** in newborns are not related to bilirubin displacement.
Question 8: A G2 P1 - 29-year-old female delivered a baby, but the baby died within 48 hours due to medical reasons. What drug will you advise to stop breast milk secretion?
- A. None of the options
- B. Ergot alkaloids
- C. Cabergoline (Correct Answer)
- D. Both B & C
Explanation: ***Cabergoline*** - **Cabergoline** is a **non-ergot dopamine agonist** that effectively inhibits pituitary prolactin secretion, leading to the suppression of lactation. - It works by acting on **D2 dopamine receptors** in the pituitary gland, thereby preventing milk secretion after delivery. - It is the **preferred first-line agent** for lactation suppression due to its superior efficacy, better tolerability, longer half-life (allowing single or twice-daily dosing over 2 days), and lower side effect profile. *None of the options* - This option is incorrect because there are specific pharmacological agents available and recommended for **lactation suppression** in such circumstances. - **Cabergoline** is a well-established and commonly used drug for this purpose. *Ergot alkaloids* - While **bromocriptine** (an ergot-derived dopamine agonist) was historically used for lactation suppression, it is no longer preferred. - **Cabergoline** has largely replaced bromocriptine due to better tolerability, longer half-life, less frequent dosing, and fewer side effects (bromocriptine causes more nausea, vomiting, and orthostatic hypotension). - Note: **Cabergoline itself is a non-ergot dopamine agonist**, making it pharmacologically distinct from ergot alkaloids. *Both B & C* - This option is incorrect because **cabergoline is not an ergot alkaloid**—it is a non-ergot dopamine agonist. - While bromocriptine (an ergot derivative) can suppress lactation, **cabergoline alone** is the preferred choice with superior efficacy and safety profile. - Combining or equating these agents is not standard clinical practice.
Question 9: What is the treatment of choice for a 5-year-old child with bedwetting?
- A. No treatment
- B. Motivational therapy (Correct Answer)
- C. Imipramine
- D. Desmopressin
Explanation: ***Motivational therapy*** - This is the **first-line active treatment** for **primary nocturnal enuresis** in children, involving encouragement, positive reinforcement (star charts), rewards, and education about bladder control. - It focuses on **behavioral strategies** and can be highly effective with parental involvement. - When intervention is pursued at age 5, motivational therapy is preferred over pharmacological options due to safety and effectiveness. *No treatment* - At age 5, **watchful waiting with reassurance** is often appropriate since nocturnal enuresis is common at this age (affects 15-20% of 5-year-olds) and has a **spontaneous resolution rate of 15% per year**. - However, when the question asks for "treatment of choice," it implies active intervention rather than observation alone. - Active behavioral therapy is preferred when bedwetting causes distress or affects the child's self-esteem. *Imipramine* - **Imipramine** is a **tricyclic antidepressant** with anticholinergic effects that can reduce bladder contractions, but it has significant side effects including **cardiac arrhythmias** and is **not first-line treatment**. - It is typically reserved for children ≥7 years after behavioral interventions fail, due to its potential adverse effects and high relapse rate after discontinuation. *Desmopressin* - **Desmopressin** is an **antidiuretic hormone analog** that reduces urine production overnight. - While effective, it is typically reserved for children ≥6 years who are unresponsive to behavioral therapy or for **short-term situational use** (e.g., sleepovers, camps). - Side effects include potential **hyponatremia** and high relapse rate after discontinuation.
Question 10: Which calcium channel blocker has the shortest duration of action?
- A. Diltiazem
- B. Amlodipine
- C. Nimodipine (Correct Answer)
- D. Verapamil
Explanation: ***Nimodipine*** - Nimodipine is a **dihydropyridine calcium channel blocker** specifically formulated for cerebral vasodilation and used in conditions like **subarachnoid hemorrhage**. - It has a relatively **short half-life** and rapid onset, making its duration of action shorter compared to other commonly used calcium channel blockers. *Amlodipine* - Amlodipine is known for its **long duration of action** and once-daily dosing due to its slow absorption and high bioavailability. - Its prolonged action is beneficial for conditions like **hypertension and angina**, where sustained vasodilation is desired. *Diltiazem* - Diltiazem's duration of action is **intermediate** compared to other calcium channel blockers, often requiring BID to TID dosing for immediate-release formulations. - It's a **non-dihydropyridine calcium channel blocker** with effects on both vascular smooth muscle and cardiac conduction. *Verapamil* - Verapamil also has an **intermediate duration of action**, similar to diltiazem, with immediate-release forms requiring multiple daily doses. - As a **non-dihydropyridine calcium channel blocker**, it has significant effects on myocardial contractility and AV nodal conduction.
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