Pediatric and Geriatric Pharmacology — MCQs

Pediatric and Geriatric Pharmacology Indian Medical PG Practice Questions and MCQs

Question 41: Which of the following is/are 1st line antitubercular drugs for children?

A. Pyrazinamide
B. Isoniazid
C. All of the options (Correct Answer)
D. Rifampicin

Explanation: ***Correct: All of the options*** All three drugs listed are **first-line antitubercular drugs** for children according to WHO and national tuberculosis treatment guidelines. **Isoniazid (H)** - Cornerstone first-line drug with potent **bactericidal activity** against actively dividing Mycobacterium tuberculosis - Highly effective and well-tolerated in children - Essential component of all standard anti-TB regimens **Rifampicin (R)** - Powerful first-line agent with **rapid bactericidal action** and sterilizing activity - Critical for shortening treatment duration - Key drug in both intensive and continuation phases **Pyrazinamide (Z)** - Important first-line drug that is **highly active in acidic environments** - Particularly effective against semi-dormant bacilli - Essential during the intensive phase to shorten treatment duration **Standard Pediatric TB Regimen:** The WHO-recommended first-line regimen for drug-sensitive TB in children includes all four first-line drugs: **Isoniazid (H), Rifampicin (R), Pyrazinamide (Z), and Ethambutol (E)**. Since all the listed options are first-line drugs, "All of the options" is the correct answer.

Question 42: The preferred drug for treating ADHD in a 7-year-old boy, whose father has a history of substance abuse:

A. Clonidine
B. Atomoxetine (Correct Answer)
C. Dexamphetamine
D. Methylphenidate

Explanation: ***Atomoxetine*** - As a **non-stimulant**, atomoxetine is preferred in patients where stimulant use is contraindicated or when there's a concern for **substance abuse potential**, such as a parental history. - It specifically inhibits the **norepinephrine transporter**, leading to increased norepinephrine levels in the prefrontal cortex, improving ADHD symptoms. *Clonidine* - While clonidine is sometimes used for ADHD, particularly for **hyperactivity** or **tics**, it is not generally considered first-line and can cause **sedation**. - Its mechanism primarily involves stimulating central alpha-2 adrenergic receptors, which can help with impulse control but is distinct from the primary action of atomoxetine. *Dexamphetamine* - This is a **stimulant medication** and is highly effective for ADHD, but it carries a higher potential for **abuse and diversion**, making it less suitable given a family history of substance abuse. - Its mechanism involves increasing dopamine and norepinephrine levels in the brain, which can be reinforcing and contribute to its abuse potential. *Methylphenidate* - Similar to dexamphetamine, methylphenidate is a **stimulant** and a first-line treatment for ADHD, but its potential for **abuse** makes it a less desirable choice in this specific clinical context. - It acts as a norepinephrine-dopamine reuptake inhibitor, increasing the availability of these neurotransmitters, but like other stimulants, its controlled substance status is a concern.

Question 43: 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 44: Which drug for ADHD has a risk of growth retardation in children?

A. Methylphenidate (Correct Answer)
B. Modafinil
C. Clonidine
D. Atomoxetine

Explanation: ***Methylphenidate*** - **Methylphenidate** (a stimulant) can cause a **transient reduction in growth velocity** due to effects on appetite suppression and potentially growth hormone secretion [1]. - While this reduction is often temporary and catch-up growth typically occurs, it is a **well-documented and clinically significant risk** requiring growth monitoring in children [1, 2]. - Among ADHD medications, stimulants like methylphenidate have the **most pronounced effect on growth** [1].*Modafinil* - **Modafinil** is primarily used for narcolepsy and other sleep disorders, not a first-line treatment for ADHD. - It works through different mechanisms than traditional stimulants and is not typically associated with growth retardation in the ADHD population.*Clonidine* - **Clonidine** is an alpha-2 adrenergic agonist used to treat ADHD, particularly for hyperactivity, impulsivity, and sleep problems. - It does **not have a known risk of growth retardation** in children.*Atomoxetine* - **Atomoxetine** is a non-stimulant medication for ADHD that works by selectively inhibiting norepinephrine reuptake. - While atomoxetine can also affect growth velocity in some children (FDA labeling includes growth monitoring recommendations), the effect is **generally less pronounced than with stimulants like methylphenidate**. - Methylphenidate remains the **most recognized** for this adverse effect among ADHD medications.

Question 45: Which vaccine traditionally required special precautions in children with severe egg allergy?

A. Measles
B. BCG
C. Hepatitis B
D. Influenza (Correct Answer)

Explanation: ***Influenza*** - The influenza vaccine was traditionally produced in **embryonated chicken eggs**, making it a concern for individuals with **severe egg allergies**. - Current guidelines generally state that individuals with egg allergy can receive the flu vaccine, but in the past, special precautions were often recommended. *Measles* - The measles vaccine (MMR) is grown in **chicken embryo fibroblast cultures**, but studies have shown no increased risk of allergic reactions in egg-allergic individuals. - It does not contain significant amounts of **egg protein**, and allergy to eggs is not a contraindication. *BCG* - The BCG vaccine (Bacille Calmette-Guérin) is derived from a strain of *Mycobacterium bovis* and is not produced using **egg components**. - It does not pose a risk for individuals with egg allergy. *Hepatitis B* - The hepatitis B vaccine is a **recombinant vaccine**, meaning it is produced using genetically engineered yeast cells, not **egg components**. - Therefore, it is safe for individuals with egg allergy.

Question 46: Which antihypertensive medication is contraindicated in pregnancy due to its potential to cause fetal renal damage?

A. Labetalol
B. Nifedipine
C. ACE inhibitors (Correct Answer)
D. Methyldopa

Explanation: ***ACE inhibitors*** - ACE inhibitors are **contraindicated in pregnancy (FDA Category D)** and can cause severe fetal renal damage, including **oligohydramnios**, **renal dysplasia**, and **anuria**, particularly when used in the second and third trimesters. - They inhibit fetal angiotensin II production, which is crucial for normal renal development and function. - **ARBs (Angiotensin Receptor Blockers)** share the same contraindication and risks. *Labetalol* - **Labetalol** is a **beta-blocker** commonly used to manage hypertension in pregnancy and is generally considered safe. - It does not have known associations with fetal renal damage. *Nifedipine* - **Nifedipine**, a **calcium channel blocker**, is another preferred agent for treating hypertension in pregnant women. - It is not contraindicated and is not associated with teratogenic effects on the fetal kidneys. *Methyldopa* - **Methyldopa** is often considered the **first-line antihypertensive** for chronic hypertension in pregnancy due to its long-standing safety record. - It works as a centrally acting alpha-agonist and does not cause fetal renal damage.

Question 47: Which of the following antiepileptic drugs is associated with causing congenital heart disease in the fetus?

A. Carbamazepine
B. Phenytoin
C. Barbiturates
D. Valproate (Correct Answer)

Explanation: ***Valproate*** - **Valproate** is associated with the **highest overall risk of major congenital malformations** among antiepileptic drugs, affecting **10-20%** of exposed fetuses - While **neural tube defects** (spina bifida) are the most characteristic malformation, **cardiac defects** (including atrial septal defects, ventricular septal defects, and coarctation of aorta) occur in approximately **2-3%** of exposed pregnancies - The teratogenic risk is **dose-dependent**, with higher doses (>1000 mg/day) carrying substantially greater risk - Valproate is classified as **FDA Category X** (contraindicated in pregnancy) due to its high teratogenic potential *Phenytoin* - **Phenytoin** is associated with **fetal hydantoin syndrome**, which includes craniofacial abnormalities, limb defects, nail hypoplasia, and growth restriction - Cardiac defects do occur with phenytoin exposure (particularly septal defects), with an estimated risk of **2-3%** - However, the **overall rate of major malformations** is lower than valproate (approximately 6-10%) - While cardiac defects are part of the phenytoin teratogenicity spectrum, valproate carries a higher absolute risk *Carbamazepine* - **Carbamazepine** is primarily associated with **neural tube defects** (0.5-1% risk), particularly spina bifida - The overall risk of major congenital malformations is **approximately 4-6%**, lower than both valproate and phenytoin - Cardiac defects can occur but are less frequently reported compared to other malformations *Barbiturates* - **Barbiturates** (such as phenobarbital) have teratogenic potential including cardiac defects and cleft palate - The overall risk of major malformations is **estimated at 5-7%** - While cardiac defects have been reported, the evidence base is less robust than for valproate, and the absolute risk is lower

Question 48: A 2-year-old boy weighing 12 kg is diagnosed with vitamin A deficiency. What is the recommended oral dose of vitamin A for him?

A. 200,000 I.U. (Correct Answer)
B. 50,000 I.U.
C. 100,000 I.U.
D. 150,000 I.U.

Explanation: ***200,000 I.U.*** - According to **WHO guidelines**, for children aged **12 months and older** with vitamin A deficiency, the recommended oral dose is **200,000 I.U.** - This dose is given immediately upon diagnosis, repeated the next day, and a third dose is given 2-4 weeks later. - Since this child is **2 years old**, he falls into the ≥12 months category requiring 200,000 I.U. *100,000 I.U.* - A dose of **100,000 I.U.** is recommended for infants aged **6-11 months** with vitamin A deficiency. - This child is 2 years old, making 100,000 I.U. an insufficient dose for his age group. *50,000 I.U.* - A dose of **50,000 I.U.** is recommended for infants **younger than 6 months** diagnosed with vitamin A deficiency. - This dose is too low for a 2-year-old child. *150,000 I.U.* - **150,000 I.U.** is not a standard WHO-recommended dose for vitamin A deficiency treatment in any pediatric age group. - This is an incorrect dosing option.

Question 49: Which drug is primarily used to promote fetal lung maturity?

A. Folic acid
B. Dexamethasone (Correct Answer)
C. Beclomethasone

Explanation: ***Dexamethasone*** - **Dexamethasone** is a synthetic glucocorticoid that rapidly crosses the placenta and stimulates the maturation of fetal lung surfactant production. - It significantly reduces the incidence and severity of **respiratory distress syndrome (RDS)** in preterm infants when administered to the mother. - **Antenatal corticosteroids** (dexamethasone or betamethasone) are given to mothers at risk of preterm delivery between 24-34 weeks of gestation. *Folic acid* - **Folic acid** is a B vitamin crucial for cell growth and DNA synthesis, primarily used to prevent **neural tube defects** in developing fetuses. - It does not have a direct role in promoting fetal lung maturity or surfactant production. *Beclomethasone* - **Beclomethasone** is an inhaled corticosteroid primarily used for the long-term management of **asthma** in children and adults. - While it is a corticosteroid, it is not typically used for systemic administration to the mother to promote fetal lung maturity due to its primary delivery method (inhalation) and limited systemic bioavailability compared to dexamethasone or betamethasone.

Question 50: Which of the following statements about the rotavirus vaccine is true?

A. It is a killed vaccine.
B. It is administered subcutaneously.
C. It is an oral pentavalent vaccine. (Correct Answer)
D. It should be given after 5 years.

Explanation: ***It is an oral pentavalent vaccine.*** - Rotavirus vaccines are **oral vaccines** that provide protection against rotavirus infection, a common cause of **severe diarrhea** in infants and young children. - **RotaTeq** is a **pentavalent live attenuated vaccine** containing five reassortant strains (G1, G2, G3, G4, and P1A) to induce a broad immune response. - **Rotarix** is a monovalent live attenuated vaccine containing one strain (G1P[8]). - Both vaccines are oral and live attenuated, but the statement correctly describes RotaTeq specifically. *It is a killed vaccine.* - The rotavirus vaccines currently in use (both RotaTeq and Rotarix) are **live attenuated vaccines**, not killed vaccines. - Live attenuated vaccines contain weakened versions of the virus that replicate in the host to stimulate an immune response without causing disease. *It is administered subcutaneously.* - The rotavirus vaccine is administered **orally**, typically dropped into the infant's mouth. - This route of administration is preferred for enteric infections like rotavirus, as it can induce **mucosal immunity** in the gastrointestinal tract. *It should be given after 5 years.* - The rotavirus vaccine is recommended for **infants and young children**, with the first dose typically given between **6 and 14 weeks of age**. - Catch-up vaccination is generally not recommended after 8 months of age, and the vaccine is not indicated for children over 5 years.

Practice by Chapter

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Polypharmacy in the Elderly

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Medication Adherence in Elderly

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Inappropriate Prescribing in Elderly

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Deprescribing Principles

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