Analgesics and Anti-inflammatory Drugs Practice Questions

Q: Which of the following best describes the mechanism of action of colchicine in acute attack of gout?

Inhibit migration of neutrophil chemotaxis. ***Inhibit migration of neutrophil chemotaxis*** - Colchicine binds to **tubulin**, preventing its polymerization into microtubules, which disrupts the **cytoskeletal function** required for neutrophil motility and migration. - By inhibiting the **chemotaxis** and phagocytosis of neutrophils into the affected joint, it reduces the **inflammatory response** triggered by urate crystals. *Inhibition of xanthine oxidase* - This is the primary mechanism of **allopurinol** and **febuxostat**, which are used for chronic gout management to lower serum uric acid levels. - It does not provide significant anti-inflammatory relief during an **acute gouty flare**. *Inhibition of cyclooxygenase (COX)* - This describes the mechanism of **NSAIDs** (like indomethacin or naproxen), which reduce prostaglandin synthesis to provide analgesia. - While NSAIDs are used for acute gout, they act through a completely different pathway than the microtubule-inhibiting effects of colchicine. *Blockade of IL-1 receptors* - This is the mechanism of **anakinra**, a biological DMARD, which targets the interleukin-1 pathway involved in the inflammatory cascade. - While the **NLRP3 inflammasome** (which produces IL-1beta) is indirectly inhibited by the downstream effects of colchicine, it is not a direct blockade of the IL-1 receptor itself.

Q: The prostaglandin inhibiting action of Aspirin is useful in the treatment of all of the following conditions except?

Uricosuria. The therapeutic effects of Aspirin are primarily mediated by the irreversible inhibition of **Cyclooxygenase (COX-1 and COX-2)** enzymes, which prevents the synthesis of **Prostaglandins (PGs)** and **Thromboxane A2 (TXA2)** [1]. **Why Uricosuria is the Correct Answer:** Aspirin has a **dose-dependent effect** on uric acid excretion that is independent of prostaglandin inhibition. At low to moderate doses (the doses typically used for analgesia), aspirin actually **inhibits the tubular secretion of uric acid**, leading to hyperuricemia (retention of uric acid). While very high doses (>5g/day) can be uricosuric, aspirin is never used for this purpose because such doses are toxic. Therefore, its prostaglandin-inhibiting action is not the mechanism for uricosuria. **Analysis of Incorrect Options:** * **Analgesia and Antipyresis:** Aspirin reduces PGE2 levels in the hypothalamus (resetting the thermoregulatory center) and at peripheral nerve endings, effectively treating pain and fever [1]. * **Closure of Ductus Arteriosus:** Patent Ductus Arteriosus (PDA) is maintained by PGE2. Inhibiting PG synthesis promotes the closure of the ductus in neonates [2]. * **Anti-inflammatory and Antiplatelet:** Inflammation is driven by PGs, and platelet aggregation is driven by TXA2 [1]. Aspirin inhibits both, making it vital for inflammatory conditions and prophylaxis against myocardial infarction [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Low dose (75-150mg):** Antiplatelet (inhibits TXA2). * **Intermediate dose (0.3-5g):** Analgesic and Antipyretic. * **High dose (>5g):** Uricosuric (but causes Salicylism). * **Contraindication:** Aspirin is contraindicated in children with viral infections to prevent **Reye’s Syndrome**.

Q: Which of the following is a new IL-1 antagonist used in rheumatoid arthritis?

Anakinra. **Explanation:** **Anakinra** is the correct answer because it is a recombinant, non-glycosylated form of the human **Interleukin-1 receptor antagonist (IL-1Ra)**. In Rheumatoid Arthritis (RA), IL-1 is a key pro-inflammatory cytokine that mediates cartilage destruction and bone resorption. Anakinra competitively inhibits the binding of IL-1α and IL-1β to the IL-1 type I receptor, thereby reducing the inflammatory response. **Analysis of Incorrect Options:** * **Rituximab (Option B):** This is a chimeric monoclonal antibody against **CD20**, a protein found primarily on the surface of B-cells. It is used in RA cases refractory to TNF inhibitors. * **Teriparatide (Option C):** This is a recombinant form of **Parathyroid Hormone (PTH)**. It is an anabolic agent used for Osteoporosis, not an anti-inflammatory for RA. * **Adalimumab (Option D):** This is a fully human monoclonal antibody directed against **TNF-α** (Tumor Necrosis Factor-alpha), not IL-1 [1]. **High-Yield NEET-PG Pearls:** * **Other IL-1 Inhibitors:** Apart from Anakinra, newer agents include **Canakinumab** (monoclonal antibody against IL-1β) and **Rilonacept** (IL-1 trap). * **Clinical Use:** Anakinra is less commonly used than TNF inhibitors due to its shorter half-life (requires daily subcutaneous injections) and lower efficacy in RA. * **Contraindication:** Never combine IL-1 antagonists with TNF inhibitors (like Adalimumab or Etanercept) due to a significantly increased risk of serious infections [2]. * **Side Effect:** Injection site reactions are the most common adverse effect. DMARDs include a diverse group of small molecule non-biologicals and biological agents used to retard the progression of arthritic tissue destruction [3].

Q: FK 506 is a type of:

Macrolide antibiotic. **Explanation:** **FK 506**, also known as **Tacrolimus**, is a potent immunosuppressant. Chemically, it is classified as a **macrolide antibiotic** (Option C) because it contains a large macrocyclic lactone ring in its structure. However, unlike erythromycin, it lacks significant antibacterial activity and is used primarily for its immunosuppressive properties. **Mechanism of Action:** Tacrolimus binds to an intracellular protein called **FK-binding protein (FKBP-12)**. This complex inhibits **calcineurin**, a phosphatase enzyme. Inhibition of calcineurin prevents the dephosphorylation of the Nuclear Factor of Activated T-cells (NFAT), thereby blocking the transcription of **Interleukin-2 (IL-2)** and other cytokines. This results in the inhibition of T-lymphocyte activation. **Analysis of Incorrect Options:** * **Option A:** It is a small molecule drug derived from the fungus *Streptomyces tsukubaensis*, not a protein-based immunoglobulin. * **Option B:** Non-depolarizing muscle relaxants (e.g., Vecuronium, Atracurium) act on nicotinic receptors at the neuromuscular junction; Tacrolimus has no such action. * **Option D:** Opioid anesthetics (e.g., Fentanyl) act on mu-opioid receptors for analgesia; Tacrolimus does not possess analgesic properties. **High-Yield Clinical Pearls for NEET-PG:** * **Indications:** Prophylaxis of organ transplant rejection (especially liver and kidney) and topically for atopic dermatitis. * **Potency:** Tacrolimus is **10–100 times more potent** than Cyclosporine. * **Side Effects:** Nephrotoxicity (most common), neurotoxicity (tremors, seizures), and **post-transplant diabetes mellitus (PTDM)**. Unlike Cyclosporine, it does *not* typically cause hirsutism or gum hyperplasia. * **Drug Interactions:** Metabolized by **CYP3A4**; levels increase with grapefruit juice or macrolide antibiotics (like Erythromycin).

Q: Which immunosuppressant acts by inhibiting mTOR and is non-nephrotoxic?

Sirolimus. **Explanation:** **Sirolimus** (also known as **Rapamycin**) is the correct answer. It belongs to the class of drugs known as **mTOR inhibitors** (mammalian Target of Rapamycin). 1. **Mechanism of Action:** Sirolimus binds to the intracellular protein **FKBP-12**. This complex then inhibits the mTOR kinase, which is a key regulator of the cell cycle. By inhibiting mTOR, it prevents the progression of T-cells from the G1 to the S phase, thereby suppressing lymphocyte proliferation. 2. **Clinical Advantage:** Unlike Calcineurin inhibitors (CNIs), Sirolimus is notably **non-nephrotoxic**. This makes it an excellent alternative or adjunct in renal transplant patients to reduce the dose of nephrotoxic drugs. **Analysis of Incorrect Options:** * **Azathioprine:** An antimetabolite that acts as a prodrug for 6-mercaptopurine. It inhibits purine synthesis but does not involve the mTOR pathway. * **Tacrolimus:** A Calcineurin inhibitor (CNI). Like Sirolimus, it binds to FKBP-12, but the complex inhibits calcineurin, not mTOR. Crucially, Tacrolimus is **highly nephrotoxic**. * **Rapamycin:** While Rapamycin is the same chemical compound as Sirolimus, in the context of standardized exams like NEET-PG, if both names are provided, "Sirolimus" is the preferred pharmacological nomenclature. (Note: In most clinical scenarios, they are synonymous, but the question structure often tests the specific drug class name). **High-Yield NEET-PG Pearls:** * **Side Effects of Sirolimus:** While it spares the kidneys, it causes **Hyperlipidemia** (most common), thrombocytopenia, and impaired wound healing. * **Drug Interaction:** Both Tacrolimus and Sirolimus are metabolized by **CYP3A4**; grapefruit juice can increase their toxicity. * **Everolimus:** A newer mTOR inhibitor with a shorter half-life than Sirolimus.

Q: Which of the following NSAIDs is preferred in the treatment of dysmenorrhea?

Mefenamic acid. **Explanation:** **Mefenamic acid** (Option C) is the preferred NSAID for the treatment of primary dysmenorrhea. The underlying pathophysiology of dysmenorrhea involves the overproduction of prostaglandins (specifically $PGF_{2\alpha}$) in the endometrium, leading to uterine hypercontractility and ischemia. Mefenamic acid is uniquely effective because it possesses a **dual mechanism of action**: 1. It inhibits the enzyme **Cyclooxygenase (COX)**, thereby reducing the synthesis of prostaglandins. 2. It acts as an **antagonist at prostaglandin receptors**, directly blocking the action of pre-formed prostaglandins on the myometrium. **Analysis of Incorrect Options:** * **A. Indomethacin:** While a potent COX inhibitor, it is associated with a high incidence of systemic side effects (GI distress, frontal headaches, and dizziness), making it a second-line choice for routine menstrual pain. * **B. Ketorolac:** This is an extremely potent analgesic primarily used for short-term management of severe acute pain (post-operative). It is not the standard of care for dysmenorrhea due to its high risk of nephrotoxicity and GI bleeding. * **D. Naproxen:** Although effective and frequently used for dysmenorrhea due to its long half-life, it lacks the specific receptor-blocking property of Mefenamic acid. **High-Yield Clinical Pearls for NEET-PG:** * **Mefenamic Acid (Fenamate):** Also used in Menorrhagia as it reduces blood loss by 20-30%. * **Side Effect:** A unique side effect of Mefenamic acid is **diarrhea** and occasionally hemolytic anemia. * **DOC for PDA:** Ibuprofen (or Indomethacin) is the drug of choice for the closure of Patent Ductus Arteriosus. * **DOC for Acute Gout:** NSAIDs (like Indomethacin or Naproxen) are first-line, but Mefenamic acid is not typically used.

Q: H1 antihistamines are beneficial in several conditions. Which of the following conditions is NOT benefited by the antagonism of histamine?

Common cold. **Explanation:** The correct answer is **Common cold** because the symptoms of the common cold (rhinorrhea, sneezing, and congestion) are primarily caused by **viral inflammation** and the release of kinins and prostaglandins, rather than histamine. While first-generation H1 antihistamines (like diphenhydramine or chlorpheniramine) are often found in over-the-counter cold remedies, their benefit is derived from their **anticholinergic (atropine-like) side effects**, which help dry up nasal secretions, rather than their antihistaminic action. **Analysis of other options:** * **Dermographism:** This is a form of physical urticaria where pressure on the skin causes a wheal-and-flare response. This reaction is directly mediated by the release of histamine from mast cells, making H1 blockers highly effective. * **Insect bite:** The local redness, itching, and swelling following an insect bite are classic Type I hypersensitivity reactions mediated by histamine release. * **Seasonal hay fever (Allergic Rhinitis):** This is a prototypical IgE-mediated allergic reaction where histamine is the primary mediator of sneezing, itching, and watery eyes. H1 antihistamines are the first-line treatment. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** H1 antihistamines are technically **inverse agonists**, not simple competitive antagonists; they stabilize the inactive state of the H1 receptor. * **First vs. Second Gen:** First-generation H1 blockers (e.g., Promethazine) cross the blood-brain barrier and are sedative. Second-generation blockers (e.g., Cetirizine, Loratadine) are non-sedating. * **Terfenadine/Astemizole:** These second-generation drugs were withdrawn because they cause **QT prolongation** and *Torsades de Pointes* when taken with CYP3A4 inhibitors (like Ketoconazole or Erythromycin). Fexofenadine is their safe active metabolite.

Q: Which of the following is an analgesic that does not inhibit prostaglandin synthesis?

Nefopam. ### Explanation **1. Why Nefopam is Correct:** Nefopam is a **non-opioid, non-NSAID** centrally acting analgesic. Unlike NSAIDs, its mechanism of action does not involve the inhibition of cyclooxygenase (COX) enzymes or prostaglandin synthesis. Instead, it acts primarily by inhibiting the reuptake of **serotonin, norepinephrine, and dopamine** (triple monoamine reuptake inhibitor). It also modulates NMDA receptors and sodium/calcium channels. This unique profile makes it useful for acute pain management without the gastrointestinal or anti-platelet side effects associated with prostaglandin inhibition. **2. Why the Other Options are Incorrect:** * **Tenoxicam & Piroxicam (Options B & D):** These are long-acting NSAIDs belonging to the **Oxicam** class. They are potent inhibitors of both COX-1 and COX-2 enzymes, thereby reducing prostaglandin synthesis. * **Ketorolac (Option C):** This is a **Pyrrolo-pyrrole** derivative NSAID known for its powerful analgesic efficacy (comparable to low-dose morphine). It is a non-selective COX inhibitor that significantly blocks prostaglandin production. **3. High-Yield Clinical Pearls for NEET-PG:** * **Nefopam & Shivering:** A high-yield clinical use of Nefopam is its effectiveness in treating **post-operative shivering**, as it resets the shivering threshold in the hypothalamus. * **Contraindications:** Due to its sympathomimetic effects (norepinephrine reuptake inhibition), it should be avoided in patients with **convulsions, glaucoma, or those taking MAO inhibitors.** * **Side Effects:** Common side effects include tachycardia, dry mouth, and urinary retention (anticholinergic-like effects). * **Analgesic Ladder:** Nefopam is often used as an "adjunct" in multimodal analgesia to reduce opioid requirements (opioid-sparing effect).

Question 1

Which of the following best describes the mechanism of action of colchicine in acute attack of gout?

Accepted Answer

Inhibit migration of neutrophil chemotaxis

Answer

Inhibition of xanthine oxidase

Answer

Inhibition of cyclooxygenase (COX)

Answer

Blockade of IL-1 receptors

Question 2

What is the mechanism by which opioids cause constipation in palliative care patients?

Accepted Answer

Activation of mu receptors in myenteric plexus reducing peristalsis

Answer

Inhibition of bile secretion

Answer

Direct toxic effect on intestinal mucosa

Answer

Dehydration due to increased renal sodium excretion

Question 3

The prostaglandin inhibiting action of Aspirin is useful in the treatment of all of the following conditions except?

Accepted Answer

Uricosuria

Answer

Analgesia and antipyresis

Answer

Closure of ductus arteriosus

Answer

Anti-inflammatory and antiplatelet aggregation

Question 4

Which of the following is a new IL-1 antagonist used in rheumatoid arthritis?

Accepted Answer

Anakinra

Answer

Rituximab

Answer

Teriparatide

Answer

Adalimumab

Question 5

FK 506 is a type of:

Accepted Answer

Macrolide antibiotic

Answer

Immunoglobulin antibody

Answer

Non-depolarizing muscle relaxant

Answer

Opioid anaesthetic

Question 6

Which immunosuppressant acts by inhibiting mTOR and is non-nephrotoxic?

Accepted Answer

Sirolimus

Answer

Azathioprine

Answer

Tacrolimus

Answer

Rapamycin

Question 7

Which of the following NSAIDs is preferred in the treatment of dysmenorrhea?

Accepted Answer

Mefenamic acid

Answer

Indomethacin

Answer

Ketorolac

Answer

Naproxen

Question 8

Aseptic meningitis has been reported as an adverse effect of which of the following drugs?

Accepted Answer

Ibuprofen

Answer

Paracetamol

Answer

Ketorolac

Answer

Nimesulide

Question 9

H1 antihistamines are beneficial in several conditions. Which of the following conditions is NOT benefited by the antagonism of histamine?

Accepted Answer

Common cold

Answer

Dermographism

Answer

Insect bite

Answer

Seasonal hay fever

Question 10

Which of the following is an analgesic that does not inhibit prostaglandin synthesis?

Accepted Answer

Nefopam

Answer

Tenoxicam

Answer

Ketorolac

Answer

Piroxicam

Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs — MCQs

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