Analgesics and Anti-inflammatory Drugs Practice Questions

Q: Which drug can exacerbate asthma secondary to irreversible nonselective inhibition of the cyclooxygenase pathway?

Aspirin. ### Explanation **Correct Option: A (Aspirin)** The question highlights two specific pharmacological characteristics: **irreversible inhibition** and **nonselective COX inhibition**. Aspirin (Acetylsalicylic acid) is the only NSAID that covalently modifies cyclooxygenase (COX-1 and COX-2) by acetylating a serine residue in the active site, leading to irreversible inhibition. **Mechanism of Asthma Exacerbation:** When the COX pathway is blocked, arachidonic acid is shunted toward the **Lipoxygenase (LOX) pathway**. This leads to an overproduction of **cysteinyl leukotrienes** (LTC4, LTD4, LTE4), which are potent bronchoconstrictors. This clinical phenomenon is known as **Aspirin-Exacerbated Respiratory Disease (AERD)** or Samter’s Triad (Asthma, Nasal polyps, and Aspirin sensitivity). **Why other options are incorrect:** * **B & C (Ibuprofen and Ketorolac):** While these are nonselective COX inhibitors that can trigger asthma via the same leukotriene shunt, their binding to the COX enzyme is **reversible** (competitive inhibition). * **D (Celecoxib):** This is a **selective COX-2 inhibitor**. It does not significantly inhibit COX-1 in the respiratory tract and is generally considered safer for patients with aspirin-sensitive asthma. **High-Yield Clinical Pearls for NEET-PG:** * **Samter’s Triad:** Asthma + Aspirin sensitivity + Nasal polyposis. * **Anti-platelet effect:** Aspirin’s effect lasts for the lifetime of a platelet (7–10 days) because platelets are anucleated and cannot synthesize new COX enzymes. * **Drug of Choice:** For patients with AERD who require an analgesic, **Acetaminophen** (in low doses) or **Selective COX-2 inhibitors** are preferred. * **Treatment of AERD:** Leukotriene receptor antagonists (e.g., **Montelukast, Zafirlukast**) are particularly effective in managing these patients.

Q: Therapeutic uses of Prostaglandin E1 include all of the following except?

Primary pulmonary hypertension. **Explanation:** The correct answer is **C. Primary pulmonary hypertension**. Prostaglandin E1 (PGE1), also known as **Alprostadil**, is a potent vasodilator and smooth muscle relaxant. While it does cause vasodilation, it is **not** the drug of choice for Primary Pulmonary Hypertension (PPH). The preferred prostaglandin for PPH is **Prostaglandin I2 (PGI2)**, specifically **Epoprostenol** or its analogs like Treprostinil and Iloprost, which have a more specific effect on the pulmonary vasculature. **Analysis of other options:** * **Medical termination of pregnancy (MTP):** **Misoprostol** is a synthetic PGE1 analog. It is used extensively in combination with Mifepristone for MTP because it induces uterine contractions and cervical ripening. * **Impotence:** Alprostadil (PGE1) can be administered via intracavernosal injection or intraurethral suppository to induce penile vasodilation and erection in patients with erectile dysfunction. * **Maintenance of Patent Ductus Arteriosus (PDA):** In neonates with cyanotic heart disease (e.g., Transposition of Great Arteries), PGE1 infusion is used to keep the ductus arteriosus open to maintain systemic or pulmonary blood flow until surgery. **High-Yield Clinical Pearls for NEET-PG:** * **PGE1 (Alprostadil/Misoprostol):** Used for PDA maintenance, NSAID-induced peptic ulcers, and MTP. * **PGE2 (Dinoprostone):** Primarily used for cervical ripening and induction of labor. * **PGF2α (Carboprost/Latanoprost):** Used for Postpartum Hemorrhage (PPH) and Glaucoma. * **PGI2 (Epoprostenol):** Used for Primary Pulmonary Hypertension and inhibiting platelet aggregation during dialysis. * **Mnemonic:** To **C**lose the ductus, use **C**yclooxygenase inhibitors (Indomethacin/Ibuprofen); to **O**pen the ductus, use Pr**O**staglandins (PGE1).

Q: Abatacept is a:

Fusion protein. **Explanation:** **Abatacept** is a recombinant **fusion protein** used primarily in the treatment of Rheumatoid Arthritis. It consists of the extracellular domain of human **CTLA-4** (Cytotoxic T-lymphocyte-associated antigen 4) fused to the **Fc portion of human IgG1**. **Mechanism of Action:** Its primary role is to act as a **selective co-stimulation modulator**. For a T-cell to become activated, it requires two signals: 1. The binding of the T-cell receptor to the Antigen-MHC complex. 2. A co-stimulatory signal (binding of **CD80/CD86** on the antigen-presenting cell to **CD28** on the T-cell). Abatacept binds to CD80 and CD86 with high affinity, preventing them from binding to CD28. This inhibits T-cell activation and the subsequent inflammatory cascade. **Analysis of Incorrect Options:** * **A. IL-1 antagonist:** This describes **Anakinra**, which is a recombinant form of the human interleukin-1 receptor antagonist. * **B. IFN-α neutralizing drug:** This refers to drugs like **Sifalimumab** or **Anifrolumab** (IFN receptor blocker), used in Systemic Lupus Erythematosus (SLE). * **C. Immunosuppressant:** While Abatacept has immunosuppressive effects, "Fusion protein" is the more specific pharmacological classification required for NEET-PG. In pharmacology questions, structural/class-specific definitions take precedence over broad functional descriptions. **High-Yield Clinical Pearls for NEET-PG:** * **Belatacept:** A related fusion protein (modified Abatacept) used specifically in renal transplantation to prevent graft rejection. * **Suffix Clue:** Drugs ending in **"-cept"** (e.g., Etanercept, Abatacept, Aflibercept) are typically **fusion proteins** involving a receptor linked to an Fc fragment. * **Contraindication:** Do not use Abatacept concurrently with TNF-inhibitors (e.g., Infliximab) due to an increased risk of serious infections.

Q: What process is inhibited by COX-2?

Cell proliferation. **Explanation:** Cyclooxygenase-2 (COX-2) is an inducible enzyme primarily expressed during inflammation and neoplasia. While COX-1 is "constitutive" (maintaining homeostatic functions like gastric protection), COX-2 is upregulated by growth factors, cytokines, and tumor promoters. **Why Cell Proliferation is the correct answer:** COX-2 plays a pivotal role in the cell cycle. It catalyzes the synthesis of Prostaglandin E2 (PGE2), which activates signaling pathways (like Wnt/β-catenin and MAPK) that stimulate **cell proliferation** and inhibit apoptosis. Consequently, the inhibition of COX-2 leads to a decrease in cell division. This is the pharmacological basis for using NSAIDs (like Celecoxib or Aspirin) in the chemoprevention of colorectal adenomas and other malignancies where COX-2 is overexpressed. **Analysis of Incorrect Options:** * **A & C (Cell Adhesion and Migration):** While COX-2 can indirectly influence the metastatic potential of cancer cells, its primary and most direct regulatory effect is on the mitotic rate and survival of the cell itself. * **B (Cell Differentiation):** COX-2 activity is generally associated with maintaining an undifferentiated, proliferative state in stem cells and cancer cells. Inhibition usually promotes or restores differentiation rather than inhibiting it. **NEET-PG High-Yield Pearls:** * **Selective COX-2 Inhibitors (Coxibs):** These lack anti-platelet effects (as platelets only express COX-1) but increase cardiovascular risk due to an imbalance between Thromboxane A2 and Prostacyclin (PGI2). * **Clinical Application:** Celecoxib is FDA-approved for reducing the number of polyps in **Familial Adenomatous Polyposis (FAP)**. * **Expression:** COX-2 is constitutively expressed in only a few sites: the **Kidney, Brain, and Spinal Cord.**

Q: A 25-year-old woman develops a sore, red, hot, swollen left knee. She has no history of trauma and no familial history of joint disease. Aspirin is effective in relieving symptoms of acute inflammation in this patient because it inhibits which of the following enzymes?

Cyclooxygenase. ### Explanation **Correct Option: A. Cyclooxygenase** Aspirin (Acetylsalicylic acid) is a Non-Steroidal Anti-Inflammatory Drug (NSAID) that exerts its anti-inflammatory, analgesic, and antipyretic effects by **irreversibly inhibiting the enzyme Cyclooxygenase (COX-1 and COX-2)**. This inhibition prevents the conversion of arachidonic acid into **prostaglandins (PGs)** and thromboxanes. Prostaglandins (specifically PGE2 and PGI2) are the primary mediators of the cardinal signs of inflammation—vasodilation (redness/heat), increased vascular permeability (swelling), and sensitization of pain receptors (soreness). **Why Incorrect Options are Wrong:** * **B. Myeloperoxidase:** This enzyme is found in neutrophil granules and is involved in the production of hypochlorous acid to kill bacteria; it is not the target of aspirin. * **C. Phospholipase A2:** This enzyme releases arachidonic acid from membrane phospholipids. It is inhibited by **Corticosteroids** (via lipocortin/annexin A1), not by NSAIDs. * **D. Superoxide dismutase:** This is an antioxidant enzyme that neutralizes superoxide radicals; it is not involved in the mechanism of action of common analgesics. **High-Yield NEET-PG Pearls:** * **Irreversible Binding:** Aspirin is unique among NSAIDs because it **acetylates** the serine residue of COX, leading to irreversible inhibition. Other NSAIDs (like Ibuprofen) are reversible inhibitors. * **Antiplatelet Effect:** At low doses (75–150 mg), aspirin selectively inhibits COX-1 in platelets, preventing Thromboxane A2 (TXA2) synthesis for the lifetime of the platelet (8–11 days). * **Zero-Order Kinetics:** At high/toxic doses, aspirin metabolism shifts from first-order to zero-order kinetics. * **Reye’s Syndrome:** Aspirin is contraindicated in children with viral infections (flu/chickenpox) due to the risk of fulminant hepatic failure and encephalopathy.

Q: All of the following are TNF alpha inhibitors except?

Omalizumab. **Explanation:** The question tests your ability to distinguish between different classes of monoclonal antibodies used in immunological disorders. **Why Omalizumab is the correct answer:** **Omalizumab** is a recombinant DNA-derived humanized monoclonal antibody that selectively binds to **free human Immunoglobulin E (IgE)**. By binding to IgE, it prevents the binding of IgE to the high-affinity receptor (FcεRI) on the surface of mast cells and basophils, thereby inhibiting the allergic cascade. It is clinically indicated for **moderate-to-severe persistent asthma** and chronic idiopathic urticaria, not for conditions requiring TNF-α inhibition. **Analysis of Incorrect Options (TNF-α Inhibitors):** * **Infliximab (Option A):** A chimeric monoclonal antibody that binds to both soluble and transmembrane forms of TNF-α. It is widely used in Crohn’s disease and Rheumatoid Arthritis (RA). * **Adalimumab (Option B):** A fully human monoclonal antibody against TNF-α. It has a lower risk of neutralizing antibody formation compared to Infliximab. * **Etanercept (Option D):** A soluble **decoy receptor** (fusion protein) that binds to TNF molecules in the circulation, preventing them from interacting with cell surface receptors. **High-Yield Clinical Pearls for NEET-PG:** * **Screening:** Before starting any TNF-α inhibitor, patients **must be screened for Latent Tuberculosis** (via TST or IGRA) because these drugs can cause reactivation of TB. * **Suffix Clues:** * *-ximab:* Chimeric (e.g., Infliximab) * *-zumab:* Humanized (e.g., Omalizumab) * *-mumab:* Fully Human (e.g., Adalimumab) * *-cept:* Receptor fusion protein (e.g., Etanercept) * **Other TNF Inhibitors:** Certolizumab (pegylated) and Golimumab.

Q: A 45-year-old male presented with severe pain in the knee and shoulder joints. A diagnosis of rheumatoid arthritis was made and the patient was started on methotrexate 15mg weekly. However, even after 6 months of treatment, recurrent episodes of arthritis continued. The physician wanted to add another disease-modifying antirheumatic drug (DMARD) that inhibits pyrimidine synthesis by inhibiting the dihydroorotate dehydrogenase enzyme. Which of the following drugs is the physician considering?

Leflunomide. ### Explanation **Correct Option: C. Leflunomide** **Mechanism of Action:** Leflunomide is a prodrug that is converted into its active metabolite, **A77 1726 (malononitrilamide)**. This metabolite acts as a potent inhibitor of the mitochondrial enzyme **dihydroorotate dehydrogenase (DHODH)**. This enzyme is critical for the **de novo synthesis of pyrimidines** (specifically UMP). Since activated T-lymphocytes require rapid pyrimidine synthesis to proliferate, Leflunomide effectively arrests the cell cycle in the G1 phase, thereby exerting its immunosuppressive effect in Rheumatoid Arthritis. **Analysis of Incorrect Options:** * **A. Sulfasalazine:** It is a DMARD used in RA, but its exact mechanism is unclear. It is thought to inhibit NF-κB and reduce cytokine production, but it does not inhibit pyrimidine synthesis. * **B. Infliximab:** This is a biological DMARD that acts as a **chimeric monoclonal antibody against TNF-α**. It does not interfere with metabolic pathways like pyrimidine synthesis. * **D. Abatacept:** This is a biological agent that inhibits T-cell costimulation by binding to **CD80 and CD86** on antigen-presenting cells, preventing their interaction with CD28 on T-cells. **High-Yield Clinical Pearls for NEET-PG:** * **Loading Dose:** Leflunomide has a very long half-life (approx. 2 weeks); hence, a loading dose is often used to reach steady state quickly. * **Side Effects:** Hepatotoxicity (monitor LFTs) and diarrhea are common. It is also highly **teratogenic**. * **Washout Procedure:** Due to its long half-life, if a patient needs to stop the drug (e.g., for pregnancy), **Cholestyramine** is administered to enhance biliary excretion and "wash out" the drug. * **Comparison:** While Methotrexate inhibits *purine* synthesis (via dihydrofolate reductase), Leflunomide inhibits *pyrimidine* synthesis.

Q: Which of the following is a second-generation H1 antihistamine?

Cetirizine. **Explanation:** The correct answer is **Cetirizine**. H1 antihistamines are classified into two generations based on their ability to cross the blood-brain barrier (BBB) and their sedative potential. **1. Why Cetirizine is correct:** Cetirizine is a **second-generation H1 antihistamine**. These drugs are highly polar, have low lipid solubility, and are substrates for the P-glycoprotein efflux pump. Consequently, they do not cross the BBB significantly, making them **non-sedating**. They also have a longer duration of action and minimal anticholinergic effects compared to the first generation. **2. Why the other options are incorrect:** * **Promethazine (Option B):** A first-generation antihistamine known for its strong sedative and antiemetic properties. It is frequently used for motion sickness and preoperative sedation. * **Cinnarizine (Option C):** A first-generation antihistamine with calcium channel blocking activity. It is primarily used for vertigo and labyrinthine disorders. * **Pheniramine (Option D):** A classic first-generation antihistamine (commonly known as Avil) used for allergic rhinitis and urticaria, but it causes significant drowsiness. **High-Yield Clinical Pearls for NEET-PG:** * **Active Metabolites:** Cetirizine is the active metabolite of Hydroxyzine; Fexofenadine is the active metabolite of Terfenadine; Loratadine is metabolized to Desloratadine. * **Safety Profile:** Fexofenadine is considered the "least sedating" antihistamine and is the drug of choice for pilots/drivers. * **Cardiac Warning:** Terfenadine and Astemizole (older 2nd gen) were withdrawn due to the risk of **QT prolongation and Torsades de Pointes**, especially when co-administered with CYP3A4 inhibitors (e.g., Erythromycin, Ketoconazole). * **Topical 2nd Gen:** Azelastine and Olopatadine are used as nasal sprays or eye drops for allergic rhinitis/conjunctivitis.

Q: Which component of sulfasalazine is responsible for the therapeutic effect in rheumatoid arthritis?

Sulfapyridine. **Explanation:** Sulfasalazine is a prodrug composed of **Sulfapyridine** and **5-aminosalicylic acid (5-ASA)** linked by a covalent azo bond. This bond is cleaved by bacterial enzymes (azoreductases) in the colon. **1. Why Sulfapyridine is correct:** In **Rheumatoid Arthritis (RA)**, sulfasalazine acts as a Disease-Modifying Antirheumatic Drug (DMARD). The **sulfapyridine** moiety is absorbed systemically from the colon and is responsible for the anti-inflammatory and immunomodulatory effects in the joints. It inhibits the release of inflammatory cytokines (like IL-1 and TNF-α) and may suppress B-cell activity. **2. Why other options are incorrect:** * **5-aminosalicylic acid (5-ASA):** This component remains largely unabsorbed and stays in the colon. It is the active moiety for **Ulcerative Colitis** and Crohn’s disease due to its local anti-inflammatory effect on the bowel mucosa. It has no role in treating systemic joint disease. * **Intact sulfasalazine molecule:** The intact molecule is poorly absorbed from the gut and serves primarily as a vehicle to deliver the two active components to the distal bowel. **High-Yield Clinical Pearls for NEET-PG:** * **Adverse Effects:** Most side effects (nausea, rashes, agranulocytosis, and reversible oligospermia) are attributed to the **sulfapyridine** component. * **Monitoring:** Due to the risk of bone marrow suppression, CBC and LFTs should be monitored. * **Metabolism:** Sulfapyridine is metabolized via **acetylation** in the liver. "Slow acetylators" are at a higher risk of toxicity. * **Safe in Pregnancy:** Sulfasalazine is generally considered one of the safer DMARDs during pregnancy (Category B).

Q: Which of the following is an anti-CD25 antibody?

Daclizumab. **Explanation:** **Correct Answer: B. Daclizumab** **Mechanism of Action:** Daclizumab (and Basiliximab) are recombinant monoclonal antibodies that act as **IL-2 receptor antagonists**. Specifically, they bind to the **α-subunit (CD25)** of the IL-2 receptor expressed on the surface of activated T-lymphocytes. By blocking this receptor, they inhibit T-cell proliferation and the subsequent immune response. They are primarily used to prevent acute organ rejection in renal transplant patients. **Analysis of Incorrect Options:** * **A. Muromonab (OKT3):** This is a murine monoclonal antibody directed against the **CD3** receptor on T-cells. It was the first monoclonal antibody used in clinical practice but has largely been replaced due to "cytokine release syndrome." * **C. Adalimumab:** This is a fully human monoclonal antibody directed against **TNF-α**. It is widely used in the management of rheumatoid arthritis, psoriasis, and inflammatory bowel disease. * **D. Trastuzumab:** This is a humanized monoclonal antibody directed against the **HER2/neu (ErbB2)** receptor. It is a cornerstone therapy for HER2-positive breast cancer and gastric cancer. **High-Yield Clinical Pearls for NEET-PG:** * **CD25 Blockers:** Remember the mnemonic **"BD"** (Basiliximab, Daclizumab) for CD25. * **Chimeric vs. Humanized:** Basiliximab is *chimeric* (-ximab), while Daclizumab is *humanized* (-zumab). * **Rituximab:** Targets **CD20** (used in Non-Hodgkin Lymphoma). * **Alemtuzumab:** Targets **CD52** (used in CLL and Multiple Sclerosis). * **Infliximab:** Another TNF-α inhibitor, but unlike Adalimumab, it is a *chimeric* antibody.

Question 1

Which drug can exacerbate asthma secondary to irreversible nonselective inhibition of the cyclooxygenase pathway?

Accepted Answer

Aspirin

Answer

Ibuprofen

Answer

Ketorolac

Answer

Celecoxib

Question 2

Therapeutic uses of Prostaglandin E1 include all of the following except?

Accepted Answer

Primary pulmonary hypertension

Answer

Medical termination of pregnancy

Answer

Impotence

Answer

Maintenance of patent ductus arteriosus (PDA)

Question 3

Abatacept is a:

Accepted Answer

Fusion protein

Answer

IL1 antagonist

Answer

IFN-a neutralizing drug

Answer

Immunosuppressant

Question 4

What process is inhibited by COX-2?

Accepted Answer

Cell proliferation

Answer

Cell adhesion

Answer

Cell differentiation

Answer

Cell migration

Question 5

A 25-year-old woman develops a sore, red, hot, swollen left knee. She has no history of trauma and no familial history of joint disease. Aspirin is effective in relieving symptoms of acute inflammation in this patient because it inhibits which of the following enzymes?

Accepted Answer

Cyclooxygenase

Answer

Myeloperoxidase

Answer

Phospholipase A2

Answer

Superoxide dismutase

Question 6

All of the following are TNF alpha inhibitors except?

Accepted Answer

Omalizumab

Answer

Infliximab

Answer

Adalimumab

Answer

Etanercept

Question 7

A 45-year-old male presented with severe pain in the knee and shoulder joints. A diagnosis of rheumatoid arthritis was made and the patient was started on methotrexate 15mg weekly. However, even after 6 months of treatment, recurrent episodes of arthritis continued. The physician wanted to add another disease-modifying antirheumatic drug (DMARD) that inhibits pyrimidine synthesis by inhibiting the dihydroorotate dehydrogenase enzyme. Which of the following drugs is the physician considering?

Accepted Answer

Leflunomide

Answer

Sulfasalazine

Answer

Infliximab

Answer

Abatacept

Question 8

Which of the following is a second-generation H1 antihistamine?

Accepted Answer

Cetirizine

Answer

Promethazine

Answer

Cinnarizine

Answer

Pheniramine

Question 9

Which component of sulfasalazine is responsible for the therapeutic effect in rheumatoid arthritis?

Accepted Answer

Sulfapyridine

Answer

Intact sulfasalazine molecule

Answer

5-aminosalicylic acid

Answer

Both sulfapyridine and 5-aminosalicylic acid

Question 10

Which of the following is an anti-CD25 antibody?

Accepted Answer

Daclizumab

Answer

Muromonab

Answer

Adalimumab

Answer

Transtuzumab

Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs — MCQs

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