Which statement is true regarding the influenza vaccine?
Which of the following substances is commonly known as an arrow poison used by indigenous South American tribes?
Which of the following vaccines is not freeze-dried?
What is the Hib conjugate vaccine made of?
Which of the following medications is not indicated for the treatment or prophylaxis of seasonal influenza?
Main function of sodium citrate in ORS?
What is the recommended regimen for post-exposure prophylaxis for HIV?
In areas with chloroquine-sensitive P. vivax, what is the preferred drug for treating the blood stages?
What is the recommended therapeutic supplementation of iron and folic acid for adults with deficiency?
Which of the following is not true about the Vi polysaccharide vaccine for typhoid?
NEET-PG 2015 - Pharmacology NEET-PG Practice Questions and MCQs
Question 101: Which statement is true regarding the influenza vaccine?
- A. The live attenuated vaccine is given by nasal spray.
- B. All statements are correct. (Correct Answer)
- C. The inactivated vaccine is used most commonly.
- D. The inactivated vaccine is given intramuscularly in the deltoid.
Explanation: ***All statements are correct.*** - Each of the preceding statements is factually accurate regarding influenza vaccines. - The **inactivated vaccine** is widely used, the **live attenuated vaccine** is administered via nasal spray, and the **inactivated vaccine** is given intramuscularly [1]. *The inactivated vaccine is used most commonly.* - The **inactivated influenza vaccine (IIV)**, given by injection, is the most frequently administered type of influenza vaccine. - It is recommended for most age groups and is safe for individuals with chronic medical conditions, pregnant women, and the elderly. *The live attenuated vaccine is given by nasal spray.* - The **live attenuated influenza vaccine (LAIV)**, also known as FluMist, is administered as a **nasal spray** [1]. - This vaccine is suitable for healthy individuals aged 2-49 years and is not recommended for pregnant women or individuals with certain immune compromising conditions. *The inactivated vaccine is given intramuscularly in the deltoid.* - The standard route of administration for the **inactivated influenza vaccine (IIV)** is via **intramuscular injection**, most commonly into the **deltoid muscle** in adults and older children [1]. - This method ensures proper absorption and an effective immune response, a common practice for many vaccines.
Question 102: Which of the following substances is commonly known as an arrow poison used by indigenous South American tribes?
- A. Opium
- B. Curare (Correct Answer)
- C. Cannabis
- D. Cyanide
Explanation: ***Curare*** - **Curare** is the traditional name for South American arrow poisons derived from plants, primarily *Chondrodendron tomentosum* and *Strychnos* species - It acts as a **competitive non-depolarizing neuromuscular blocking agent**, blocking nicotinic receptors at the neuromuscular junction - Causes **skeletal muscle paralysis** by competing with acetylcholine, leading to respiratory failure in prey - **Clinical relevance:** Tubocurarine (d-tubocurarine), derived from curare, was historically used as a muscle relaxant in surgery; modern derivatives include atracurium, vecuronium, and rocuronium *Opium* - **Opium** is derived from *Papaver somniferum* (opium poppy) and contains alkaloids like morphine and codeine - Acts on **opioid receptors** in the CNS to produce analgesia and sedation - Not used as an arrow poison by South American tribes; its effects are analgesic rather than paralytic *Cannabis* - **Cannabis** (*Cannabis sativa*) contains psychoactive compounds like THC (tetrahydrocannabinol) - Acts on **cannabinoid receptors** producing psychoactive and analgesic effects - Not used as an arrow poison; lacks the rapid paralytic action needed for hunting *Cyanide* - **Cyanide** inhibits cytochrome c oxidase, blocking cellular respiration and causing rapid cell death - While highly toxic, it is **not the traditional arrow poison** of South American indigenous tribes - Traditional arrow poisons like curare cause neuromuscular paralysis rather than cellular asphyxiation
Question 103: Which of the following vaccines is not freeze-dried?
- A. Measles Vaccine
- B. Diphtheria, Pertussis, and Tetanus (DPT) Vaccine (Correct Answer)
- C. Rubella Vaccine
- D. BCG Vaccine
Explanation: ***Diphtheria, Pertussis, and Tetanus (DPT) Vaccine*** - The DPT vaccine is a **liquid vaccine** that contains inactivated toxins and bacterial components, making it stable in liquid form. - It does not require **freeze-drying** because its components are chemically stable and do not degrade significantly in solution. *Measles Vaccine* - The measles vaccine is a **live attenuated vaccine** that needs to be freeze-dried to maintain the viability and stability of the live virus. - Freeze-drying helps preserve the vaccine's potency by removing water, which prevents degradation during storage and transport. *Rubella Vaccine* - Similar to the measles vaccine, the rubella vaccine is a **live attenuated vaccine** and is therefore provided in a freeze-dried form. - This process ensures the long-term stability and efficacy of the viral components, which would otherwise degrade in a liquid state. *BCG Vaccine* - The BCG (Bacillus Calmette-Guérin) vaccine is a **live attenuated bacterial vaccine** used against tuberculosis, and it is also manufactured as a freeze-dried product. - Freeze-drying is essential for maintaining the viability of the live attenuated *Mycobacterium bovis* strain.
Question 104: What is the Hib conjugate vaccine made of?
- A. Capsular polysaccharide
- B. Purified protein with carrier
- C. Cell wall polysaccharide
- D. Capsular polysaccharide with carrier (Correct Answer)
Explanation: ***Capsular polysaccharide with carrier*** - The Hib conjugate vaccine uses a **polysaccharide capsule** from *Haemophilus influenzae* type b (Hib) covalently linked to a **protein carrier** [1]. - This conjugation allows activated B cells to present the polysaccharide to T helper cells, inducing a strong **T-cell dependent immune response** and **immunological memory**, especially in infants [1]. *Capsular polysaccharide* - A vaccine made only of **capsular polysaccharide** would be a **polysaccharide vaccine**, which induces a **T-cell independent immune response**. - This type of vaccine is **poorly immunogenic in infants** and does not generate long-lasting memory. *Purified protein with carrier* - This describes components of some **protein subunit vaccines**, but not specifically the Hib vaccine, which targets the polysaccharide capsule. - While it employs a carrier protein, the primary antigen is the **polysaccharide**, not a purified bacterial protein. *Cell wall polysaccharide* - The Hib vaccine specifically targets the **capsular polysaccharide**, which is distinct from the general cell wall polysaccharides found in the bacterial outer membrane. - The **capsule** is the primary virulence factor and target for protective immunity in Hib.
Question 105: Which of the following medications is not indicated for the treatment or prophylaxis of seasonal influenza?
- A. Amantadine
- B. Rimantadine
- C. Oseltamivir
- D. Acyclovir (Correct Answer)
Explanation: ***Acyclovir*** - **Acyclovir** is an antiviral medication specifically used to treat infections caused by **herpes viruses** (e.g., HSV, VZV), not influenza viruses. - It works by inhibiting **viral DNA polymerase**, a mechanism distinct from how anti-influenza drugs act. - **This drug has never been indicated for influenza** - it is the correct answer to this "not indicated" question. *Amantadine* - **Amantadine** is an M2 ion channel inhibitor that **was indicated** for influenza A treatment and prophylaxis. - Although no longer recommended due to widespread **resistance** among circulating influenza strains, it remains a drug that was formally indicated for seasonal influenza. *Rimantadine* - **Rimantadine** is also an M2 ion channel inhibitor, structurally related to amantadine, with a similar mechanism of action. - Like amantadine, it **was indicated** for influenza treatment or prophylaxis but is no longer recommended due to high rates of **resistance** in circulating influenza A viruses. *Oseltamivir* - **Oseltamivir** is a **neuraminidase inhibitor** currently approved and recommended for the treatment and prophylaxis of both influenza A and B. - It reduces viral spread by preventing the release of new virions from infected cells and remains a first-line agent for seasonal influenza.
Question 106: Main function of sodium citrate in ORS?
- A. To increase absorption of glucose by cotransport
- B. To correct electrolyte imbalance
- C. To correct Acidosis (Correct Answer)
- D. To correct dehydration
Explanation: ***To correct Acidosis*** - **Sodium citrate** provides a source of **bicarbonate** precursor, which helps to correct the **metabolic acidosis** often associated with severe dehydration and diarrhea. - In the body, citrate is metabolized into bicarbonate, raising the blood pH and counteracting the effects of acidosis. *To increase absorption of glucose by cotransport* - The absorption of glucose and sodium is coupled, meaning the presence of **sodium enhances glucose absorption** through the **SGLT1 cotransporter**. - While sodium is essential for glucose absorption, **citrate's primary role is not this direct cotransport mechanism**. *To correct electrolyte imbalance* - ORS formulations contain various electrolytes like **sodium chloride** and **potassium chloride** to rectify electrolyte imbalances caused by diarrhea. - While sodium citrate contributes to sodium levels, its specific function goes beyond just general electrolyte correction to address the **acid-base balance**. *To correct dehydration* - The overall purpose of ORS is to **rehydrate the patient** by providing fluids and electrolytes, which helps restore circulating volume. - While citrate is a component of ORS, **rehydration also depends on the water and other salts** present in the solution, not solely on citrate.
Question 107: What is the recommended regimen for post-exposure prophylaxis for HIV?
- A. Zidovudine + Lamivudine + Lopinavir/ritonavir for 28 days
- B. Tenofovir disoproxil fumarate + Emtricitabine + Raltegravir for 28 days
- C. Single dose Tenofovir + Emtricitabine + Raltegravir
- D. Tenofovir disoproxil fumarate + Emtricitabine + Dolutegravir for 28 days (Correct Answer)
Explanation: ***Tenofovir disoproxil fumarate + Emtricitabine + Dolutegravir for 28 days*** - This is the **current first-line recommended regimen** for **HIV post-exposure prophylaxis (PEP)** according to WHO (2021), CDC, and Indian NACO guidelines. - It includes two **nucleoside reverse transcriptase inhibitors (NRTIs)** and an **integrase strand transfer inhibitor (INSTI)**. - **Dolutegravir** is preferred over Raltegravir due to **superior efficacy, better tolerability, higher barrier to resistance, once-daily dosing**, and fewer drug interactions. - The duration of **28 days** is crucial for effective PEP to cover the window period for potential HIV integration and replication. *Tenofovir disoproxil fumarate + Emtricitabine + Raltegravir for 28 days* - This was the **previous standard PEP regimen** and is still an acceptable alternative if Dolutegravir is contraindicated or unavailable. - Raltegravir requires **twice-daily dosing** compared to Dolutegravir's once-daily regimen, which may affect adherence. - The 28-day duration is correct, but Raltegravir is no longer the first-line INSTI choice in current guidelines. *Single dose Tenofovir + Emtricitabine + Raltegravir* - A **single dose** of these medications is insufficient for **post-exposure prophylaxis (PEP)** as HIV replication needs to be suppressed over an extended period to prevent seroconversion. - PEP typically requires a **28-day course** to be effective. *Zidovudine + Lamivudine + Lopinavir/ritonavir for 28 days* - While this is an older, effective **antiretroviral regimen**, it is **not the preferred first-line PEP regimen** due to a higher incidence of side effects, particularly with zidovudine (anemia, nausea). - Modern guidelines favor regimens with **Tenofovir/Emtricitabine + Dolutegravir** due to better tolerability and superior efficacy.
Question 108: In areas with chloroquine-sensitive P. vivax, what is the preferred drug for treating the blood stages?
- A. Mefloquine
- B. Artesunate
- C. Quinine
- D. Chloroquine (Correct Answer)
Explanation: ***Correct Option: Chloroquine***- **Chloroquine** remains the **first-line treatment** for **chloroquine-sensitive P. vivax** infections due to its high efficacy and safety profile [1, 2].- It rapidly clears **blood-stage parasites**, alleviating acute symptoms of malaria [3].- In areas where P. vivax remains sensitive, chloroquine is preferred due to low cost, good tolerability, and proven effectiveness [1, 2].*Incorrect Option: Mefloquine*- **Mefloquine** is typically reserved for areas with **chloroquine-resistant P. falciparum** or for prophylaxis in such regions.- Its use is generally avoided when less toxic and equally effective options like chloroquine are available for sensitive strains.- Associated with more neuropsychiatric side effects.*Incorrect Option: Artesunate*- **Artesunate** is an **artemisinin derivative**, primarily used for severe malaria or in areas with **multi-drug resistant P. falciparum**.- While effective, it is not the preferred first-line agent for chloroquine-sensitive P. vivax due to the availability of simpler, equally effective treatments.- Typically used in combination therapy (ACT) for resistant strains.*Incorrect Option: Quinine*- **Quinine** is an older antimalarial, often used for **severe malaria** or in cases of **chloroquine-resistant P. falciparum**.- It has a higher incidence of side effects compared to chloroquine (cinchonism, hypoglycemia) and is not the preferred choice for chloroquine-sensitive P. vivax.- Requires longer treatment duration with more monitoring.
Question 109: What is the recommended therapeutic supplementation of iron and folic acid for adults with deficiency?
- A. 20 mg iron, 500 mcg folic acid
- B. 40 mg iron, 250 mcg folic acid
- C. 100 mg iron, 500 mcg folic acid (Correct Answer)
- D. 100 mg iron, 100 mcg folic acid
Explanation: ***100 mg iron, 500 mcg folic acid*** - For adults with **iron deficiency anemia**, the therapeutic dose of elemental iron is typically **100-200 mg daily**, commonly given as ferrous sulfate 325 mg (containing ~65 mg elemental iron) 2-3 times daily. **100 mg is an appropriate therapeutic dose**. - For **folic acid deficiency**, the standard therapeutic dose is **1-5 mg (1000-5000 mcg) daily** for treating established deficiency. However, **500 mcg (0.5 mg)** represents a minimal therapeutic/high prophylactic dose that may be used in milder deficiencies or as initial supplementation. Among the given options, this is the most appropriate combination. *20 mg iron, 500 mcg folic acid* - **20 mg of iron** is grossly insufficient for therapeutic supplementation in iron deficiency anemia and would fail to correct the anemia adequately. - While 500 mcg folic acid has some therapeutic value, the **iron dose is far too low** for treatment. *40 mg iron, 250 mcg folic acid* - **40 mg of iron** is a prophylactic dose (used in pregnancy or prevention) but is **insufficient for therapeutic correction** of established iron deficiency anemia. - **250 mcg of folic acid** is also a prophylactic dose and inadequate for treating established deficiency. *100 mg iron, 100 mcg folic acid* - **100 mg of iron** is an appropriate therapeutic dose for treating **iron deficiency anemia**. - However, **100 mcg of folic acid** is purely a maintenance/prophylactic dose found in multivitamins and is **grossly insufficient** for treating established folic acid deficiency.
Question 110: Which of the following is not true about the Vi polysaccharide vaccine for typhoid?
- A. Given intramuscularly
- B. Given at birth (Correct Answer)
- C. Revaccination at 3 years
- D. Single dose is given
Explanation: ***Given at birth*** - The **typhoid Vi polysaccharide vaccine is not administered at birth**. It is recommended for individuals **2 years of age**. - Vaccines given at birth protect against diseases with significant **neonatal risk**, such as Hepatitis B and BCG (tuberculosis). - This is the **FALSE** statement, making it the correct answer to this "not true" question. *Single dose is given* - The Vi polysaccharide vaccine is administered as a **single 0.5 mL dose**. - This single dose provides protection against *Salmonella typhi* for approximately 3 years. - This statement is **TRUE**. *Revaccination at 3 years* - For ongoing protection, **revaccination is recommended every 3 years** for individuals at continued risk of typhoid exposure. - The booster dose maintains adequate protective antibody levels. - This statement is **TRUE**. *Given intramuscularly* - The Vi polysaccharide vaccine is administered via the **intramuscular (IM) route**, typically in the deltoid muscle. - This is the standard recommended route of administration. - This statement is **TRUE**.