INI-CET 2024 — Pharmacology
7 Previous Year Questions with Answers & Explanations
A 30-year-old woman has experienced the loss of her newborn. She is currently producing breast milk leading to discomfort and the risk of developing a breast abscess due to milk stasis and incomplete emptying. Which of the following drugs can be used to prevent this complication?
Which of the following is not a polysaccharide vaccine?
In which of the following conditions are cannabinoids not commonly used for treatment?
Drug of choice for Enterococcus infection in a patient allergic to penicillin?
Cannabidiol is not used for
Which of the following anti-leprosy drugs can cause skin hyperpigmentation?
The site of action of the loop diuretic furosemide is:
INI-CET 2024 - Pharmacology INI-CET Practice Questions and MCQs
Question 1: A 30-year-old woman has experienced the loss of her newborn. She is currently producing breast milk leading to discomfort and the risk of developing a breast abscess due to milk stasis and incomplete emptying. Which of the following drugs can be used to prevent this complication?
- A. Cabergoline (Correct Answer)
- B. Chlorpromazine
- C. Metoclopramide
- D. Mifepristone
Explanation: ***Cabergoline*** - **Cabergoline** is a dopamine agonist that inhibits prolactin secretion, thereby suppressing lactation and preventing breast engorgement and its complications after childbirth. - It has a longer duration of action compared to bromocriptine, allowing for less frequent dosing and better patient compliance in lactation suppression. *Chlorpromazine* - **Chlorpromazine** is an antipsychotic medication primarily used to treat psychotic disorders; it doesn't suppress lactation. - While it can cause hyperprolactinemia as a side effect due to its antidopaminergic action, it is not used to manage lactation or its complications. *Metoclopramide* - **Metoclopramide** is a dopamine receptor antagonist that *increases* prolactin levels, and is sometimes used to *stimulate* lactation, not suppress it. - It enhances gastrointestinal motility and is primarily used as an antiemetic or for gastric emptying disorders. *Mifepristone* - **Mifepristone** is a progesterone receptor antagonist primarily used for medical abortion and induction of labor. - It is not indicated for the suppression of lactation or the prevention of breast engorgement.
Question 2: Which of the following is not a polysaccharide vaccine?
- A. Pneumococcal vaccine
- B. Meningococcal vaccine
- C. H. Influenzae B vaccine
- D. Hepatitis B vaccine (Correct Answer)
Explanation: ***Hepatitis B vaccine (recombinant protein vaccine)*** - This is a **recombinant protein vaccine** which contains **HBsAg** (Hepatitis B surface antigen) produced in yeast. - As it uses a protein antigen, it is not a polysaccharide vaccine. *Pneumococcal vaccine (includes polysaccharide forms)* - There are two types: **Pneumococcal Polysaccharide Vaccine (PPSV23)** which is a pure polysaccharide vaccine, and **Pneumococcal Conjugate Vaccine (PCV13, PCV15, PCV20)** which contains polysaccharides conjugated to a protein carrier. - Both types utilize **polysaccharide antigens** from *Streptococcus pneumoniae* to elicit an immune response. *Meningococcal vaccine (includes polysaccharide forms)* - Similar to pneumococcal vaccines, there are **meningococcal polysaccharide vaccines (MPSV4)** and **meningococcal conjugate vaccines (MCV4)**. - These vaccines use **polysaccharides** from the capsule of *Neisseria meningitidis* as their immunogenic component, either alone or conjugated. *H. Influenza B vaccine (conjugate vaccine derived from polysaccharides)* - This is a **conjugate vaccine** that uses a **polysaccharide capsule antigen** from *Haemophilus influenzae type B* (Hib) chemically linked to a protein carrier. - Conjugation improves immunogenicity, especially in infants, by converting the T-independent polysaccharide antigen into a T-dependent one.
Question 3: In which of the following conditions are cannabinoids not commonly used for treatment?
- A. Tuberous sclerosis
- B. Rett syndrome (Correct Answer)
- C. Lennox-Gastaut Syndrome
- D. Dravet syndrome
Explanation: ***Rett syndrome*** - Cannabinoids are **NOT commonly used** as an established treatment for **Rett syndrome** - While some research is exploring their potential therapeutic role, they remain **investigational only** and lack FDA approval for this indication - Current management focuses on symptomatic treatment including physical therapy, anti-epileptics for seizures, and supportive care - Unlike the other conditions listed, there is **no established cannabinoid therapy** for Rett syndrome in clinical practice *Dravet syndrome* - **Cannabidiol (CBD/Epidiolex)** is **FDA-approved** and commonly used for treatment of seizures associated with **Dravet syndrome** - Demonstrates significant efficacy in reducing seizure frequency in this severe infantile-onset epilepsy - Represents a major therapeutic advance for this treatment-resistant condition *Tuberous sclerosis* - **Cannabidiol (CBD/Epidiolex)** received **FDA approval in 2018** for treatment of seizures associated with **tuberous sclerosis complex (TSC)** - Commonly used as an adjunctive therapy alongside other treatments like vigabatrin or mTOR inhibitors (everolimus) - Clinical trials demonstrated significant reduction in seizure frequency in TSC patients *Lennox-Gastaut Syndrome* - **Cannabidiol (CBD/Epidiolex)** is **FDA-approved** for seizures associated with **Lennox-Gastaut Syndrome (LGS)** - Commonly used in this severe epileptic encephalopathy characterized by multiple seizure types and developmental delay - Effective in reducing seizure burden in patients refractory to traditional anti-epileptic drugs
Question 4: Drug of choice for Enterococcus infection in a patient allergic to penicillin?
- A. Streptomycin
- B. Cephalosporin
- C. Vancomycin (Correct Answer)
- D. Rifampicin
Explanation: ***Vancomycin*** - **Vancomycin** is a glycopeptide antibiotic that is effective against **Gram-positive bacteria**, including *Enterococcus*, especially in patients with a **penicillin allergy**. - It inhibits **cell wall synthesis** by binding to the D-Ala-D-Ala terminus of peptidoglycan precursors, a different mechanism from penicillins. *Streptomycin* - **Streptomycin** is an aminoglycoside that inhibits **protein synthesis** and is primarily used in **combination therapy** for serious *Enterococcal* infections, but typically alongside a cell-wall active agent (like penicillin or vancomycin) for synergistic killing in endocarditis or other severe infections. - It is not usually recommended as a **monotherapy** for *Enterococcus*, especially in the context of penicillin allergy, as it doesn't provide bactericidal activity on its own against all enterococcal strains. *Cephalosporin* - **Cephalosporins** are **not active** against *Enterococcus spp.* as these bacteria intrinsically lack the **penicillin-binding proteins (PBPs)** that cephalosporins target effectively. - This **intrinsic resistance** makes cephalosporins an inappropriate choice for treating *Enterococcal* infections, regardless of penicillin allergy status. *Rifampicin* - **Rifampicin** is an antibiotic primarily used for **Mycobacterial infections** (e.g., tuberculosis) and some **Staphylococcal infections**, often in combination to prevent resistance. - It has **poor activity** against *Enterococcus* and is not a recommended treatment for *Enterococcal* infections.
Question 5: Cannabidiol is not used for
- A. Rett syndrome (Correct Answer)
- B. Lennox-Gastaut syndrome
- C. Dravet syndrome
- D. Tuberous sclerosis complex
Explanation: ***Rett syndrome*** - **Cannabidiol (CBD)** is not an approved or commonly used treatment for Rett syndrome, which is a **neurodevelopmental disorder** primarily affecting girls. - Treatment for Rett syndrome focuses on managing symptoms with supportive care, **physiotherapy**, occupational therapy, and medications for specific issues like seizures or gastrointestinal problems. *Dravet syndrome* - **Cannabidiol (Epidiolex)** is approved in many regions for the treatment of seizures associated with **Dravet syndrome**, a severe form of epilepsy. - It works by modulating the **endocannabinoid system**, which plays a role in seizure control. *Lennox-Gastaut syndrome* - **Cannabidiol (Epidiolex)** is also approved for the treatment of seizures associated with **Lennox-Gastaut syndrome**, another severe and intractable childhood epilepsy. - Its efficacy in reducing seizure frequency in LGS has been demonstrated in clinical trials. *Tuberous sclerosis complex* - While not as widely established as for Dravet or Lennox-Gastaut, **cannabidiol (Epidiolex)** has shown promise and is approved in some regions for treating seizures associated with **tuberous sclerosis complex (TSC)**. - TSC is a genetic disorder causing benign tumors in multiple organs, often leading to epilepsy.
Question 6: Which of the following anti-leprosy drugs can cause skin hyperpigmentation?
- A. Clofazimine (Correct Answer)
- B. Rifampicin
- C. Ofloxacin
- D. Dapsone
Explanation: ***Clofazimine*** - **Clofazimine** is known to cause dose-dependent **hyperpigmentation** of the skin, ranging from reddish-brown to dark brown, and can also discolor bodily fluids. - This side effect is due to the drug's accumulation in macrophages and subsequent deposition in the dermis and subcutaneous fat. *Rifampicin* - **Rifampicin** can cause harmless **reddish-orange discoloration** of urine, sweat, tears, and other bodily secretions. - It is not typically associated with **skin hyperpigmentation** (darkening of the skin itself). *Ofloxacin* - **Ofloxacin** is a fluoroquinolone antibiotic primarily used in leprosy treatment as a second-line agent. - Its common side effects include gastrointestinal disturbances and nervous system effects, but **skin hyperpigmentation** is not a characteristic adverse event. *Dapsone* - **Dapsone** is a sulfone drug and a cornerstone of leprosy treatment, but it is not associated with **skin hyperpigmentation**. - Its most notable side effects include **hemolysis**, especially in patients with **G6PD deficiency**, and methemoglobinemia.
Question 7: The site of action of the loop diuretic furosemide is:
- A. Distal convoluted tubule
- B. Descending limb of loop of Henle
- C. Proximal convoluted tubule
- D. Thick ascending limb of loop of Henle (Correct Answer)
Explanation: ***Thick ascending limb of loop of Henle*** - Furosemide, a **loop diuretic**, acts by inhibiting the **Na+-K+-2Cl- cotransporter (NKCC2)** in the luminal membrane of the epithelial cells in the thick ascending limb. - This inhibition prevents the reabsorption of these ions, leading to increased excretion of **sodium**, **potassium**, **chloride**, and water. *Distal convoluted tubule* - This is the primary site of action for **thiazide diuretics**, which inhibit the **Na+-Cl- cotransporter**. - While some water reabsorption occurs here, it is not the main target for loop diuretics like furosemide. *Descending limb of loop of Henle* - This segment is primarily permeable to **water** due to aquaporins but impermeable to solutes, allowing for passive water reabsorption. - No significant transport mechanisms are directly targeted by furosemide here. *Proximal convoluted tubule* - The proximal tubule is where the majority of filtered **sodium**, **water**, and other solutes are reabsorbed. - **Carbonic anhydrase inhibitors** (e.g., acetazolamide) primarily act here.