UPSC-CMS 2020 - Pharmacology PYQs Practice Questions

Q: All of the following are true about Bedaquiline (BDQ) EXCEPT:

It is a bacteriostatic drug. ***It is a bacteriostatic drug*** - **Bedaquiline (BDQ)** is a novel anti-tuberculosis drug that is **bactericidal** against *Mycobacterium tuberculosis*, meaning it kills the bacteria rather than just inhibiting their growth. - Its bactericidal action is crucial for treating multi-drug resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. *It has extended half-life* - **Bedaquiline** has a very **long terminal elimination half-life**, which can extend up to several months. - This extended half-life allows for less frequent dosing schedules (e.g., once daily or thrice weekly after an initial loading phase). *It specifically targets mycobacterial ATP synthase* - **Bedaquiline** specifically inhibits **mycobacterial ATP synthase**, an enzyme essential for energy production in *Mycobacterium tuberculosis* [1]. - This unique mechanism of action contributes to its effectiveness against traditional drug-resistant strains [1]. *It has high volume of tissue distribution* - **Bedaquiline** is highly lipophilic and extensively distributed into tissues, resulting in a **large volume of distribution**. - This extensive tissue distribution contributes to its long half-life and allows it to reach therapeutic concentrations within the infection sites. [Practice more Pharmacology PYQs on OnCourse]

Q: What is the recommended dose regimen of Vitamin A for the treatment of early stages of Xerophthalmia?

2 lac IU on two successive days. ***2 lac IU on two successive days*** - The **WHO-recommended treatment protocol** for xerophthalmia (including early stages) involves a **3-dose regimen**: 200,000 IU immediately, followed by 200,000 IU the next day, and a third dose at least 2 weeks later. - The **first two doses on consecutive days** represent the critical initial treatment phase to rapidly replenish vitamin A stores and prevent progression to sight-threatening corneal damage. - This regimen applies to children **12 months and older and adults**; infants under 12 months receive 100,000 IU doses. *Single massive dose of 2 lac International Units (IU)* - While a high dose is essential, **a single dose alone is insufficient** for treating xerophthalmia according to WHO guidelines. - The second dose on the consecutive day is critical to ensure adequate tissue saturation and prevent progression of corneal lesions. - Single-dose regimens are used for **prophylaxis in high-risk populations**, not for active treatment of xerophthalmia. *2 doses of 1 lac IU at a gap of one week* - **100,000 IU doses** are recommended for **infants under 12 months of age**, not for older children and adults with xerophthalmia. - The one-week interval does not match the WHO protocol, which requires the second dose on the **very next day** to ensure rapid correction. *2 doses of 1 lac IU in two successive days* - This dosing regimen is appropriate for **infants aged 6-12 months** with xerophthalmia, where each dose is 100,000 IU. - For children **12 months and older and adults**, the standard dose is **200,000 IU (2 lac IU)**, making this dosage insufficient for the typical patient population. [Practice more Pharmacology PYQs on OnCourse]

Q: Which one of the following is the antibiotic of choice for the prevention of Rheumatic Heart Disease?

Benzathine Benzyl Penicillin. ***Benzathine Benzyl Penicillin*** - It is the antibiotic of choice for the **prevention of Rheumatic Heart Disease (RHD)** due to its **long-acting nature** and effectiveness against **Group A Streptococcus (GAS)**. - A single intramuscular injection provides **sustained therapeutic levels** for several weeks, crucial for preventing recurrent GAS infections that lead to RHD. *Doxycycline* - Not effective for **primary prevention of Rheumatic Fever** or RHD as it is not a first-line agent against **Group A Streptococcus**. - Mainly used for **atypical bacteria** and certain parasitic infections. *Procaine Penicillin* - It has a shorter duration of action compared to **benzathine penicillin**. - Requires more frequent injections, making it less suitable for **long-term prophylaxis** in RHD prevention. *Ciprofloxacin* - This is a **fluoroquinolone antibiotic** and is not the antibiotic of choice for **Group A Streptococcus infections**. - Its use in this context could contribute to **antibiotic resistance** without providing effective prophylaxis for RHD. [Practice more Pharmacology PYQs on OnCourse]

Question 1

All of the following are true about Bedaquiline (BDQ) EXCEPT:

Accepted Answer

It is a bacteriostatic drug

Answer

It has extended half life

Answer

It specifically targets mycobacterial ATP synthase

Answer

It has high volume of tissue distribution

Question 2

What is the recommended dose regimen of Vitamin A for the treatment of early stages of Xerophthalmia?

Accepted Answer

2 lac IU on two successive days

Answer

Single massive dose of 2 lac International Units (IU)

Answer

2 doses of 1 lac IU at a gap of one week

Answer

2 doses of 1 lac IU in two successive days

Question 3

Which one of the following is the antibiotic of choice for the prevention of Rheumatic Heart Disease?

Accepted Answer

Benzathine Benzyl Penicillin

Answer

Doxycycline

Answer

Procaine Penicillin

Answer

Ciprofloxacin

UPSC-CMS 2020 — Pharmacology