UPSC-CMS 2019 - Pharmacology PYQs Practice Questions

Q: All of the following are hormonal agents used in treatment of cancer EXCEPT:

Irinotecan. ***Irinotecan*** - **Irinotecan** is a **chemotherapeutic agent** that acts as a **topoisomerase I inhibitor**, interfering with DNA replication and repair. - It works through a **cytotoxic mechanism** directly killing cancer cells, rather than modulating hormonal pathways. *Cabergoline* - **Cabergoline** is a **dopamine agonist** primarily used to treat **prolactinomas**, which are prolactin-producing pituitary tumors. - While it treats a tumor, its mechanism is **hormonal modulation** by reducing prolactin secretion, not direct cytotoxicity. *Anastrozole* - **Anastrozole** is an **aromatase inhibitor** used in estrogen receptor-positive breast cancer. - It works by **blocking the conversion of androgens to estrogens**, thereby reducing estrogen levels that fuel cancer growth. *Leuprolide* - **Leuprolide** is a **GnRH agonist** used in prostate cancer, breast cancer, and other hormone-sensitive conditions. - It initially stimulates, then continuously downregulates, the **pituitary gland's production of LH and FSH**, leading to reduced testosterone or estrogen levels. [Practice more Pharmacology PYQs on OnCourse]

Q: Which one of the following drugs does NOT interfere with efficacy of oral contraceptive pills and increase the failure rates?

Ranitidine. ***Ranitidine*** - **Ranitidine** is an H2 receptor antagonist that reduces stomach acid and does not interact with the **cytochrome P450 enzyme system**, which metabolizes oral contraceptives. - This means it does not significantly alter the **pharmacokinetics** of oral contraceptive pills, ensuring their efficacy is maintained. *Barbiturates* - **Barbiturates** are potent inducers of the **hepatic cytochrome P450 enzyme system**, specifically CYP3A4. - This induction accelerates the metabolism of estrogen and progestin components of oral contraceptives, leading to **lower serum levels** and reduced contraceptive efficacy. *Rifampicin* - **Rifampicin** is a strong inducer of the **hepatic cytochrome P450 enzyme system**, particularly CYP3A4, which is responsible for metabolizing steroid hormones. - This accelerated metabolism significantly reduces the serum concentrations of oral contraceptive hormones, thereby **decreasing their effectiveness** and increasing the risk of unintended pregnancy. *Ampicillin* - **Ampicillin**, and other broad-spectrum antibiotics, can theoretically interfere with oral contraceptive efficacy by disrupting the **enterohepatic recirculation** of estrogens. - This disruption leads to a decrease in the reabsorption of estrogen metabolites from the gut, resulting in **lower circulating estrogen levels** and potentially reduced contraceptive protection. [Practice more Pharmacology PYQs on OnCourse]

Q: Which one of the following antihypertensive drugs is NOT safe during pregnancy?

ACE-inhibitors. ***ACE-inhibitors*** - **ACE inhibitors** (e.g., enalapril, lisinopril) are **contraindicated** in pregnancy due to their association with severe fetal abnormalities, including **renal agenesis**, **oligohydramnios**, and **fetal death** [1], [2]. - They should be discontinued as soon as pregnancy is confirmed or suspected due to their known **teratogenic effects** [1], [2].*Labetalol* - **Labetalol**, a combined alpha- and beta-blocker, is considered one of the **first-line agents** for managing hypertension in pregnancy. - It has a good safety profile for both the mother and the fetus and is commonly used in conditions like **preeclampsia**.*Nifedipine* - **Nifedipine**, a calcium channel blocker, is also a **safe and effective** option for treating hypertension during pregnancy. - It is frequently used for managing **chronic hypertension** and **preeclampsia** due to its rapid onset of action and tolerability.*Alpha-methyl dopa* - **Alpha-methyl dopa** (methyldopa) is considered one of the **safest and most extensively studied** antihypertensive medications for use in pregnancy. - It is often the **first-choice agent** for chronic hypertension during pregnancy due to its long-standing track record of safety for the fetus. [Practice more Pharmacology PYQs on OnCourse]

Q: The drug of choice for chemoprophylaxis to health care personnel and close contacts of suspected or confirmed case of pandemic influenza A (H1N1) is:

Oseltamivir. ***Oseltamivir*** - **Oseltamivir** is the recommended drug for chemoprophylaxis against pandemic influenza A (H1N1) for healthcare personnel and close contacts [1, 2]. - This recommendation is based on its effectiveness against the **neuraminidase** of the H1N1 virus, preventing viral release and spread. *Ribavirin* - **Ribavirin** is an antiviral agent used for conditions like chronic hepatitis C and RSV, but it is not recommended for influenza chemoprophylaxis. - Its mechanism of action and efficacy profile do not make it a primary choice for preventing H1N1 infection. *Amantadine* - **Amantadine** targets the M2 ion channel of influenza A viruses, but many H1N1 strains, including the pandemic strain, developed **resistance** to this drug [1]. - Due to widespread resistance, **amantadine** and rimantadine are no longer recommended for routine influenza treatment or prophylaxis [1]. *Zanamivir* - **Zanamivir** is another **neuraminidase inhibitor** effective against influenza A and B, but it is administered via inhalation. - While effective, **oseltamivir** is generally preferred for chemoprophylaxis due to its oral administration, making it more convenient for widespread use [2]. [Practice more Pharmacology PYQs on OnCourse]

Q: All of the following drugs are effective for treatment of hookworm infection in single dose EXCEPT:

Piperazine. ***Piperazine*** - **Piperazine** is primarily effective against **Ascaris lumbricoides** and **Enterobius vermicularis**, acting as a depolarizing neuromuscular blocker. - It is **not effective** against hookworm infections and is therefore unsuitable for treating the human reservoir of hookworms. *Albendazole* - **Albendazole** is a broad-spectrum anthelminthic highly effective against hookworm infections, including **Necator americanus** and **Ancylostoma duodenale**. - A **single dose** is often sufficient due to its effectiveness in eliminating adult worms and reducing egg excretion. *Levamisole* - **Levamisole** is an anthelminthic that can be effective against hookworm species, working as a **ganglionic stimulant** causing paralysis of the worms. - A **single dose** regimen is typically adequate for hookworm treatment. *Pyrantel* - **Pyrantel pamoate** is effective against hookworms by causing **neuromuscular blockade**, leading to expulsion of the worms. - It is often given as a **single dose** for effective treatment of hookworm infections. [Practice more Pharmacology PYQs on OnCourse]

Question 1

All of the following are hormonal agents used in treatment of cancer EXCEPT:

Accepted Answer

Irinotecan

Answer

Cabergoline

Answer

Leuprolide

Answer

Anastrozole

Question 2

Which one of the following drugs does NOT interfere with efficacy of oral contraceptive pills and increase the failure rates?

Accepted Answer

Ranitidine

Answer

Barbiturates

Answer

Rifampicin

Answer

Ampicillin

Question 3

Which one of the following antihypertensive drugs is NOT safe during pregnancy?

Accepted Answer

ACE-inhibitors

Answer

Labetalol

Answer

Nifedipine

Answer

Alpha-methyl dopa

Question 4

The drug of choice for chemoprophylaxis to health care personnel and close contacts of suspected or confirmed case of pandemic influenza A (H1N1) is:

Accepted Answer

Oseltamivir

Answer

Ribavirin

Answer

Amantadine

Answer

Zanamivir

Question 5

All of the following drugs are effective for treatment of hookworm infection in single dose EXCEPT:

Accepted Answer

Piperazine

Answer

Albendazole

Answer

Levamisole

Answer

Pyrantel

UPSC-CMS 2019 — Pharmacology