UPSC-CMS 2024 — Pharmacology

Q: Which one of the following drugs is most effective in the treatment of gestational trophoblastic neoplasia?

Methotrexate. ***Methotrexate*** - **Methotrexate** is the most commonly used first-line chemotherapy for **low-risk gestational trophoblastic neoplasia (GTN)**, with cure rates exceeding 90% as a single agent. - It works by inhibiting **dihydrofolate reductase**, thereby blocking DNA synthesis and cell proliferation in rapidly dividing trophoblastic cells. - Administered as a single agent in various regimens (weekly IM, 5-day course, or 8-day alternating with folinic acid). *Actinomycin D* - **Actinomycin D** is an equally effective alternative first-line agent for low-risk GTN with similar cure rates to methotrexate. - However, the question asks for the "most effective," and both drugs have comparable efficacy; methotrexate is often preferred initially due to its favorable side effect profile and ease of administration. - Actinomycin D is frequently used when methotrexate resistance develops or as part of combination therapy for high-risk disease. *Cisplatin* - **Cisplatin** is a platinum-based chemotherapy drug reserved for **high-risk or resistant GTN**, typically as part of multi-drug regimens like EMA-CO (Etoposide, Methotrexate, Actinomycin D, Cyclophosphamide, Vincristine). - While effective in combination therapy, it is not used as first-line monotherapy for GTN. *Gemcitabine* - **Gemcitabine** is an antimetabolite used in various cancers but is **not a standard drug** for GTN treatment. - It may be considered for **refractory or resistant cases** as part of salvage therapy, but is not part of standard first-line or second-line protocols for GTN. [Practice more Pharmacology PYQs on OnCourse]

Q: Ulipristal acetate (progesterone receptor modulator) should not be prescribed as emergency contraceptive in women with

liver dysfunction. ***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. [Practice more Pharmacology PYQs on OnCourse]

Q: Which of the following are major complications of oral pills? 1. Cholestasis jaundice 2. Chloasma and acne 3. Venous thromboembolism 4. Breast cancer Select the correct answer using the code given below.

1, 2 and 3. ***1, 2 and 3*** - **Cholestasis jaundice** is a rare but serious hepatic complication of oral contraceptive pills (OCPs), caused by the estrogen component leading to impaired bile flow. - **Venous thromboembolism (VTE)** is one of the most serious and well-documented major complications of OCPs, with increased risk particularly in the first year of use and with higher estrogen doses. - **Chloasma and acne** are common dermatological side effects of OCPs. While technically not "life-threatening major complications," they are clinically significant adverse effects that affect quality of life and compliance. Some classifications include these as "major" due to their frequency and impact on continuation. - Note: The distinction between "major complications" and "common side effects" can vary by source. This answer reflects the inclusive interpretation. *1, 3 and 4* - This option includes **breast cancer** as a major complication. Current evidence shows a small increased risk during active use that diminishes after discontinuation. However, the relationship is complex and not consistently classified as a "major complication" in standard teaching. - It excludes **chloasma and acne**, which are very common adverse effects frequently listed among OCP-related problems. *1, 2 and 4* - This option includes **breast cancer**, which has nuanced and often conflicting evidence regarding its association with OCPs. - It excludes **venous thromboembolism**, which is indisputably the most serious life-threatening complication of oral contraceptive use and must be included in any list of major complications. *2, 3 and 4* - This option excludes **cholestasis jaundice**, which is a recognized serious hepatic complication of OCPs. - It incorrectly includes **breast cancer** as a major complication while omitting cholestatic jaundice, which is more consistently classified as a complication in pharmacology texts. [Practice more Pharmacology PYQs on OnCourse]

Q: A 25-year-old newly married female on liver enzyme inducers is requesting contraceptive advice in family planning clinic. Which of the following would be the most reliable method of contraception for her?

Depo-Provera injection. ***Depo-Provera injection*** - Among the listed options, **Depo-Provera** (medroxyprogesterone acetate depot injection) is considered the most reliable for women on enzyme-inducing drugs - While **enzyme inducers do affect progestin-only injectables**, the effect is **less pronounced** than with combined oral contraceptives due to the **high dose and depot formulation** - Provides **long-acting contraception** (3 months) that is **not user-dependent**, eliminating issues with daily compliance - **Note:** Current guidelines suggest considering **shortened dosing intervals** (10-11 weeks instead of 12) or preferably **copper IUD** (non-hormonal, unaffected by drug interactions) as first-line, but among these options, this is most reliable *Combined oral contraceptive pill* - **Combined OCPs** contain both estrogen and progestin, which undergo **extensive hepatic metabolism** - **Enzyme-inducing drugs** (rifampicin, phenytoin, carbamazepine, phenobarbital, St. John's wort) significantly **increase metabolism**, reducing plasma levels by up to **50%** - This leads to **contraceptive failure** and unintended pregnancy - **Least suitable option** for this patient *Diaphragm* - A **barrier method** that is **unaffected by drug interactions** - However, has a **higher typical-use failure rate** (12% per year) compared to highly effective methods - Requires **proper fitting, insertion technique, and use with spermicide** - **User-dependent** effectiveness makes it less reliable than long-acting methods *Male condom* - **Barrier method** with **no drug interaction concerns** - **Typical-use failure rate** of approximately **13% per year** due to inconsistent or incorrect use - Effectiveness is **highly user-dependent** - Less reliable than long-acting hormonal methods for pregnancy prevention [Practice more Pharmacology PYQs on OnCourse]

4 Previous Year Questions with Answers & Explanations

Questions

All Subjects Anatomy (1)Anesthesiology (1)Biochemistry (2)Community Medicine (32)Dermatology (1)Internal Medicine (14)Microbiology (2)Obstetrics and Gynecology (27)Ophthalmology (1)Orthopaedics (4)Pathology (5)Pediatrics (2)Pharmacology (4)Physiology (5)Surgery (14)

Which one of the following drugs is most effective in the treatment of gestational trophoblastic neoplasia?

Ulipristal acetate (progesterone receptor modulator) should not be prescribed as emergency contraceptive in women with

Which of the following are major complications of oral pills? 1. Cholestasis jaundice 2. Chloasma and acne 3. Venous thromboembolism 4. Breast cancer Select the correct answer using the code given below.

A 25-year-old newly married female on liver enzyme inducers is requesting contraceptive advice in family planning clinic. Which of the following would be the most reliable method of contraception for her?

UPSC-CMS 2024 - Pharmacology UPSC-CMS Practice Questions and MCQs

Question 1: Which one of the following drugs is most effective in the treatment of gestational trophoblastic neoplasia?

A. Actinomycin D
B. Cisplatin
C. Gemcitabine
D. Methotrexate (Correct Answer)

Explanation: ***Methotrexate*** - **Methotrexate** is the most commonly used first-line chemotherapy for **low-risk gestational trophoblastic neoplasia (GTN)**, with cure rates exceeding 90% as a single agent. - It works by inhibiting **dihydrofolate reductase**, thereby blocking DNA synthesis and cell proliferation in rapidly dividing trophoblastic cells. - Administered as a single agent in various regimens (weekly IM, 5-day course, or 8-day alternating with folinic acid). *Actinomycin D* - **Actinomycin D** is an equally effective alternative first-line agent for low-risk GTN with similar cure rates to methotrexate. - However, the question asks for the "most effective," and both drugs have comparable efficacy; methotrexate is often preferred initially due to its favorable side effect profile and ease of administration. - Actinomycin D is frequently used when methotrexate resistance develops or as part of combination therapy for high-risk disease. *Cisplatin* - **Cisplatin** is a platinum-based chemotherapy drug reserved for **high-risk or resistant GTN**, typically as part of multi-drug regimens like EMA-CO (Etoposide, Methotrexate, Actinomycin D, Cyclophosphamide, Vincristine). - While effective in combination therapy, it is not used as first-line monotherapy for GTN. *Gemcitabine* - **Gemcitabine** is an antimetabolite used in various cancers but is **not a standard drug** for GTN treatment. - It may be considered for **refractory or resistant cases** as part of salvage therapy, but is not part of standard first-line or second-line protocols for GTN.

Question 2: 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 3: Which of the following are major complications of oral pills? 1. Cholestasis jaundice 2. Chloasma and acne 3. Venous thromboembolism 4. Breast cancer Select the correct answer using the code given below.

A. 1, 2 and 3 (Correct Answer)
B. 1, 3 and 4
C. 1, 2 and 4
D. 2, 3 and 4

Explanation: ***1, 2 and 3*** - **Cholestasis jaundice** is a rare but serious hepatic complication of oral contraceptive pills (OCPs), caused by the estrogen component leading to impaired bile flow. - **Venous thromboembolism (VTE)** is one of the most serious and well-documented major complications of OCPs, with increased risk particularly in the first year of use and with higher estrogen doses. - **Chloasma and acne** are common dermatological side effects of OCPs. While technically not "life-threatening major complications," they are clinically significant adverse effects that affect quality of life and compliance. Some classifications include these as "major" due to their frequency and impact on continuation. - Note: The distinction between "major complications" and "common side effects" can vary by source. This answer reflects the inclusive interpretation. *1, 3 and 4* - This option includes **breast cancer** as a major complication. Current evidence shows a small increased risk during active use that diminishes after discontinuation. However, the relationship is complex and not consistently classified as a "major complication" in standard teaching. - It excludes **chloasma and acne**, which are very common adverse effects frequently listed among OCP-related problems. *1, 2 and 4* - This option includes **breast cancer**, which has nuanced and often conflicting evidence regarding its association with OCPs. - It excludes **venous thromboembolism**, which is indisputably the most serious life-threatening complication of oral contraceptive use and must be included in any list of major complications. *2, 3 and 4* - This option excludes **cholestasis jaundice**, which is a recognized serious hepatic complication of OCPs. - It incorrectly includes **breast cancer** as a major complication while omitting cholestatic jaundice, which is more consistently classified as a complication in pharmacology texts.

Question 4: A 25-year-old newly married female on liver enzyme inducers is requesting contraceptive advice in family planning clinic. Which of the following would be the most reliable method of contraception for her?

A. Diaphragm
B. Male condom
C. Depo-Provera injection (Correct Answer)
D. Combined oral contraceptive pill

Explanation: ***Depo-Provera injection*** - Among the listed options, **Depo-Provera** (medroxyprogesterone acetate depot injection) is considered the most reliable for women on enzyme-inducing drugs - While **enzyme inducers do affect progestin-only injectables**, the effect is **less pronounced** than with combined oral contraceptives due to the **high dose and depot formulation** - Provides **long-acting contraception** (3 months) that is **not user-dependent**, eliminating issues with daily compliance - **Note:** Current guidelines suggest considering **shortened dosing intervals** (10-11 weeks instead of 12) or preferably **copper IUD** (non-hormonal, unaffected by drug interactions) as first-line, but among these options, this is most reliable *Combined oral contraceptive pill* - **Combined OCPs** contain both estrogen and progestin, which undergo **extensive hepatic metabolism** - **Enzyme-inducing drugs** (rifampicin, phenytoin, carbamazepine, phenobarbital, St. John's wort) significantly **increase metabolism**, reducing plasma levels by up to **50%** - This leads to **contraceptive failure** and unintended pregnancy - **Least suitable option** for this patient *Diaphragm* - A **barrier method** that is **unaffected by drug interactions** - However, has a **higher typical-use failure rate** (12% per year) compared to highly effective methods - Requires **proper fitting, insertion technique, and use with spermicide** - **User-dependent** effectiveness makes it less reliable than long-acting methods *Male condom* - **Barrier method** with **no drug interaction concerns** - **Typical-use failure rate** of approximately **13% per year** due to inconsistent or incorrect use - Effectiveness is **highly user-dependent** - Less reliable than long-acting hormonal methods for pregnancy prevention