Analgesics and Anti-inflammatory Drugs Practice Questions

Q: Long-term use of aspirin in rheumatoid arthritis is limited by its propensity to cause which of the following?

Gastric mucosal damage. ### Explanation **Correct Answer: C. Gastric mucosal damage** **Mechanism of Action:** Aspirin (Acetylsalicylic acid) is a non-selective inhibitor of the **Cyclooxygenase (COX)** enzymes [3]. In the management of Rheumatoid Arthritis (RA), high anti-inflammatory doses are required [2]. Aspirin inhibits **COX-1**, which is responsible for synthesizing cytoprotective prostaglandins ($PGE_2$ and $PGI_2$) in the gastric mucosa [3]. These prostaglandins normally inhibit gastric acid secretion and promote mucus/bicarbonate production. Their depletion leads to increased acid damage, erosions, and peptic ulcers, making gastric intolerance the most common dose-limiting side effect in long-term therapy [1]. **Analysis of Incorrect Options:** * **A. Metabolic acidosis:** This is a feature of **acute salicylate poisoning** (toxic doses), not typical long-term therapeutic use. In adults, it is usually preceded by respiratory alkalosis. * **B. Hypersensitivity reactions:** While serious (e.g., Aspirin-Exacerbated Respiratory Disease), these are idiosyncratic and occur in a small percentage of the population, rather than being a dose-dependent limitation for most RA patients [2]. * **D. Salicylism:** This is a syndrome of mild toxicity (tinnitus, dizziness, headache). While it occurs with high doses, gastric distress usually manifests earlier and more frequently in chronic management [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Zero-order kinetics:** At anti-inflammatory doses (high doses), aspirin follows capacity-limited elimination. * **Samter’s Triad:** Aspirin sensitivity, Bronchial Asthma, and Nasal polyps. * **Reye’s Syndrome:** Aspirin is contraindicated in children with viral infections (Varicella/Influenza) due to the risk of hepatic encephalopathy. * **Anti-platelet effect:** Occurs at low doses (75–150 mg) via irreversible inhibition of COX-1 in platelets (thromboxane $A_2$ reduction) [3].

Q: Which of the NSAIDs can be administered via the parenteral route?

Ketorolac. **Explanation:** **Ketorolac** is a potent NSAID primarily used for its high analgesic efficacy, which is comparable to low-dose morphine. It is the most commonly used NSAID for the management of acute, moderate-to-severe postoperative pain via the **parenteral route (IM/IV)**. While it is also available in oral and ophthalmic forms, its systemic use is strictly limited to a maximum of **5 days** due to a high risk of gastrointestinal bleeding and renal toxicity. **Analysis of Options:** * **Ketorolac (Correct):** It is specifically designed for short-term parenteral use to bypass the first-pass metabolism and provide rapid onset of action in acute settings. * **Ibuprofen:** While an IV formulation (Caldolor) exists globally, in the context of standard medical examinations and traditional pharmacology, it is primarily recognized as an **oral** propionic acid derivative. * **Naproxen:** This is a long-acting NSAID used mainly for chronic inflammatory conditions like rheumatoid arthritis; it is administered **orally**. * **Fenoprofen:** Another propionic acid derivative used for arthritis and mild pain, available only in **oral** formulations. **High-Yield Clinical Pearls for NEET-PG:** * **Other Parenteral NSAIDs:** Apart from Ketorolac, **Diclofenac** and **Parecoxib** (a prodrug of Valdecoxib) are also available for parenteral administration. * **Topical/Ophthalmic Use:** Ketorolac is frequently used as 0.5% ophthalmic drops for seasonal allergic conjunctivitis and post-cataract surgery inflammation. * **Key Contraindication:** Avoid Ketorolac in patients with renal impairment or those at high risk of peptic ulcer disease.

Q: Muscular rigidity caused by opioids is due to agonistic effect on which receptor?

Mu. **Explanation:** **1. Why Mu (μ) is Correct:** Opioid-induced muscle rigidity (specifically "wooden chest syndrome") is a well-known side effect primarily associated with high-dose, rapid intravenous administration of potent lipophilic opioids like **Fentanyl, Sufentanil, and Remifentanil** [1]. This effect is mediated by **Mu (μ) receptors** located in the **striatum** and the **substantia nigra**. Activation of these receptors modulates GABAergic and dopaminergic pathways, leading to increased motor neuron output and skeletal muscle stiffness. This is clinically significant because it can interfere with bag-mask ventilation during anesthesia induction. **2. Why Other Options are Incorrect:** * **Kappa (κ):** These receptors are primarily associated with spinal analgesia, miosis, and **dysphoria/hallucinations**. They do not play a significant role in systemic muscular rigidity. * **Delta (δ):** These receptors contribute to supraspinal/spinal analgesia and may modulate emotional responses. While they share some properties with Mu receptors, they are not the primary mediators of motor rigidity. * **Sigma (σ):** Formerly classified as opioid receptors, they are now considered non-opioid binding sites. They are associated with psychotomimetic effects (hallucinations) and mydriasis, but not opioid-induced rigidity. **3. High-Yield Clinical Pearls for NEET-PG:** * **Management:** Opioid-induced rigidity is best managed with **Neuromuscular Blocking Agents (NMBAs)** like Succinylcholine or Vecuronium. Opioid antagonists like **Naloxone** can also reverse it but will also negate the analgesic effect. * **Wooden Chest Syndrome:** Specifically refers to the rigidity of thoracic and abdominal muscles, making ventilation nearly impossible. * **Receptor Mnemonic:** * **Mu:** Analgesia, Respiratory depression, **Rigidity**, Constipation, Euphoria. * **Kappa:** Analgesia, **Dysphoria**, Miosis.

Q: Which drugs inhibit the formation of IL-2?

Cycloserine. **Explanation** The question asks for the drug that inhibits the **formation** (synthesis) of Interleukin-2 (IL-2). **1. Why Cyclosporine is the Correct Answer:** Cyclosporine is a **Calcineurin inhibitor**. Under normal physiological conditions, an increase in intracellular calcium activates calcineurin, a phosphatase. Calcineurin then dephosphorylates the **Nuclear Factor of Activated T-cells (NFAT)**, allowing it to enter the nucleus and promote the transcription of the **IL-2 gene**. By inhibiting calcineurin, Cyclosporine prevents the dephosphorylation of NFAT, thereby blocking the synthesis (formation) of IL-2. This leads to a decrease in T-cell proliferation. **2. Analysis of Incorrect Options:** * **Cycloserine (Option A):** This is an antitubercular drug (second-line) that inhibits bacterial cell wall synthesis by acting as an analog of D-alanine. It has no role in IL-2 inhibition. * **OKT-3 (Option C):** This is a monoclonal antibody against the **CD3 receptor** on T-cells. It works by depleting T-cells or causing TCR internalization, rather than specifically inhibiting the formation of IL-2. * **Tacrolimus (Option D):** While Tacrolimus is also a calcineurin inhibitor and *does* inhibit IL-2 formation, **Cyclosporine** is the classic textbook answer for this specific mechanism in competitive exams unless multiple options are allowed. (Note: In many clinical contexts, both B and D are correct; however, Cyclosporine is the prototype). **3. High-Yield Clinical Pearls for NEET-PG:** * **Cyclosporine Side Effects:** Nephrotoxicity (most common), Gingival Hyperplasia, Hirsutism, and Hypertension. * **Tacrolimus Side Effects:** Similar to Cyclosporine but causes **Alopecia** (instead of hirsutism) and is more likely to cause **Post-transplant Diabetes Mellitus (PTDM)**. * **Sirolimus (Rapamycin):** Unlike the above, it inhibits the **response** to IL-2 (by inhibiting mTOR) rather than its formation.

Q: Which of the following is the longest-acting NSAID?

Piroxicam. **Explanation:** The correct answer is **Piroxicam**. The duration of action of an NSAID is primarily determined by its **plasma half-life ($t_{1/2}$)**. Piroxicam belongs to the **Oxicam** derivative class and is characterized by an exceptionally long half-life of approximately **45–50 hours**. This pharmacological profile allows for **once-daily dosing**, which significantly improves patient compliance in chronic conditions like rheumatoid arthritis and osteoarthritis. **Analysis of Incorrect Options:** * **Aspirin:** It has a very short plasma half-life (approx. 15–20 minutes) because it is rapidly hydrolyzed to salicylic acid. Even its active metabolite, salicylate, has a dose-dependent half-life (3–15 hours), which is much shorter than Piroxicam. * **Ibuprofen:** A propionic acid derivative with a short half-life of about **2 hours**. It requires frequent dosing (3–4 times daily) to maintain therapeutic levels. * **Acetaminophen (Paracetamol):** While technically an antipyretic-analgesic with weak anti-inflammatory action, its half-life is also short, typically **2–3 hours**. **High-Yield Clinical Pearls for NEET-PG:** * **Longest-acting NSAID:** Piroxicam (Half-life ~50 hours). * **Shortest-acting NSAID:** Aspirin or Diclofenac (Half-life ~1–2 hours). * **Oxicam class:** Includes Tenoxicam (even longer half-life than Piroxicam, ~70 hours, but Piroxicam is the standard exam answer) and Meloxicam (preferential COX-2 inhibitor). * **Side Effect Profile:** Due to its long half-life and enterohepatic recirculation, Piroxicam is associated with a higher risk of **gastric mucosal ulceration** and GI bleeding compared to shorter-acting agents.

Q: Leflunomide is used in the treatment of which condition?

Rheumatoid arthritis. **Explanation:** **Leflunomide** is a Disease-Modifying Antirheumatic Drug (DMARD) primarily used in the management of **Rheumatoid Arthritis (RA)**. **Why Option A is correct:** Leflunomide is a prodrug that is converted into its active metabolite, **A77 1726**. Its primary mechanism of action is the inhibition of the enzyme **Dihydroorotate Dehydrogenase (DHODH)**. This enzyme is crucial for the *de novo* synthesis of pyrimidines. Since activated T-lymphocytes depend on *de novo* synthesis for proliferation (rather than the salvage pathway), Leflunomide effectively inhibits T-cell expansion and the subsequent inflammatory response in RA. **Why incorrect options are wrong:** * **B. Dermatomyositis:** While immunosuppressants are used, the first-line treatments are typically corticosteroids and conventional DMARDs like Methotrexate or Azathioprine. Leflunomide is not the standard of care. * **C. Bony metastasis:** This is managed with bisphosphonates (like Zoledronate), Denosumab, or radiotherapy to prevent skeletal-related events. * **D. Postmenopausal osteoporosis:** This is treated with Bisphosphonates, SERMs (Raloxifene), or Teriparatide to increase bone mineral density. **High-Yield Clinical Pearls for NEET-PG:** * **Loading Dose:** It has a very long half-life (approx. 2 weeks); hence, a loading dose was traditionally used (though often skipped now to reduce toxicity). * **Washout Procedure:** If a patient experiences toxicity or plans pregnancy, **Cholestyramine** is administered to enhance drug elimination via biliary interruption. * **Side Effects:** Hepatotoxicity (monitor LFTs), diarrhea, alopecia, and it is highly **teratogenic** (Category X). * **Comparison:** Its efficacy in RA is considered comparable to Methotrexate.

Q: What is the most important side effect of aspirin?

Gastritis. **Explanation:** **Aspirin (Acetylsalicylic acid)** is a non-selective, irreversible inhibitor of Cyclooxygenase (COX-1 and COX-2) enzymes. **Why Gastritis is the correct answer:** The most frequent and clinically significant side effect of aspirin is **gastric mucosal damage (Gastritis/Peptic Ulcers)**. This occurs via two mechanisms: 1. **Systemic effect:** Inhibition of COX-1 reduces the synthesis of protective prostaglandins (PGE2 and PGI2), which are essential for maintaining the gastric mucosal barrier, secreting bicarbonate, and regulating blood flow. 2. **Local effect:** Aspirin is an organic acid; it causes direct chemical irritation to the gastric epithelium and can lead to "ion trapping" within mucosal cells, causing cellular damage. **Analysis of Incorrect Options:** * **B. Edema:** While NSAIDs can cause sodium and water retention by inhibiting renal prostaglandins, this is less common with aspirin compared to drugs like Piroxicam or Indomethacin. * **C. Kidney damage:** Chronic use can lead to analgesic nephropathy (papillary necrosis), but this is typically a long-term complication rather than the "most important" or most common acute side effect. * **D. Hypersensitivity:** This manifests as "Aspirin-exacerbated respiratory disease" (Aspirin Asthma) due to a shift in arachidonic acid metabolism toward the leukotriene pathway. While serious, it occurs only in susceptible individuals (approx. 10% of asthmatics). **High-Yield Clinical Pearls for NEET-PG:** * **Reye’s Syndrome:** Aspirin is contraindicated in children with viral infections (Varicella/Influenza) due to the risk of hepatic encephalopathy. * **Salicylism:** Toxicity presents with **Tinnitus** (earliest sign), vertigo, and respiratory alkalosis. * **Antiplatelet action:** Aspirin irreversibly inhibits COX-1 in platelets for their entire lifespan (8–11 days). * **Zero-order kinetics:** Aspirin follows zero-order elimination at high/toxic doses.

Q: Rofecoxib as compared to indomethacin is:

Less likely to cause gastric ulcer and their complications. The core concept behind this question is the **selectivity of COX inhibition**. **1. Why Option A is correct:** Indomethacin is a non-selective NSAID that inhibits both COX-1 and COX-2 enzymes. COX-1 is "constitutive" and responsible for producing cytoprotective prostaglandins ($PGE_2$ and $PGI_2$) in the gastric mucosa. Inhibiting COX-1 leads to gastric erosions and ulcers. **Rofecoxib** is a **selective COX-2 inhibitor** [1, 3]. Since COX-2 is primarily induced at sites of inflammation, sparing COX-1 allows the gastric mucosal barrier to remain intact, significantly reducing the risk of GI ulcers and bleeding compared to non-selective agents like indomethacin [1, 3]. **2. Why other options are incorrect:** * **Option B:** Selective COX-2 inhibitors are **equally effective**, but not superior, to non-selective NSAIDs in managing pain and inflammation in rheumatoid arthritis. Their advantage is safety (GI profile), not increased efficacy [1, 3]. * **Option C:** Both COX-1 and COX-2 are expressed in the kidneys. Therefore, selective COX-2 inhibitors like Rofecoxib **can still cause renal complications** (e.g., edema, hypertension, and renal failure) similar to traditional NSAIDs [1, 2]. **High-Yield Clinical Pearls for NEET-PG:** * **The "Coxib" Paradox:** While Rofecoxib is GI-friendly, it was withdrawn globally (VIGOR study) because it increases the risk of **myocardial infarction and stroke** [1, 2, 3]. This is due to the suppression of vascular $PGI_2$ (vasodilator/anti-aggregatory) without affecting Thromboxane $A_2$ (vasoconstrictor/pro-aggregatory). * **Drug of Choice:** Indomethacin remains the drug of choice for **Ankylosing Spondylitis** and **Patent Ductus Arteriosus (PDA)**. * **Key Contraindication:** Avoid selective COX-2 inhibitors in patients with established ischemic heart disease [2, 3].

Q: Which of the following opioid analgesics acts primarily through mu opioid receptors?

Pentazocine. The question asks for an opioid that acts **primarily** through mu (μ) receptors. However, there appears to be a discrepancy in the provided key: **Pentazocine** is actually a **kappa (κ) receptor agonist** and a weak mu (μ) receptor antagonist/partial agonist. In standard pharmacological classification, **Methadone** and **Pethidine** are pure mu-agonists [1], while **Buprenorphine** is a partial mu-agonist [1]. If we follow the provided key (A), it is important to note that Pentazocine is the prototype of **agonist-antagonist** opioids. Pentazocine (Correct per key): It acts as an agonist at **kappa (κ) receptors** (mediating spinal analgesia and dysphoria) and has weak antagonistic or partial agonistic activity at **mu (μ) receptors**. It is unique because it can precipitate withdrawal in opioid-dependent individuals. **Methadone (Incorrect):** A potent, long-acting **pure mu-receptor agonist** [1]. It is primarily used in the management of opioid withdrawal and maintenance therapy due to its long half-life and minimal withdrawal symptoms. **Buprenorphine (Incorrect):** A **partial mu-agonist** and kappa-antagonist. It has a high affinity for mu receptors but low intrinsic activity (ceiling effect for respiratory depression) [1]. **Pethidine (Meperidine) (Incorrect):** A **pure mu-agonist** [1]. It is notable for its metabolite, *normeperidine*, which can cause seizures, and its lack of miosis (it causes mydriasis due to atropine-like action). **High-Yield Clinical Pearls for NEET-PG:** 1. **Pentazocine Side Effects:** Characterized by "psychotomimetic" effects (hallucinations, dysphoria) due to kappa stimulation. 2. **Pethidine:** Preferred in biliary colic (less sphincter of Oddi spasm than Morphine) and for shivering. 3. **Buprenorphine:** Used in "Office-based" opioid detoxification; its effects are not easily reversed by Naloxone due to slow receptor dissociation [1].

Question 1

Long-term use of aspirin in rheumatoid arthritis is limited by its propensity to cause which of the following?

Accepted Answer

Gastric mucosal damage

Answer

Metabolic acidosis

Answer

Hypersensitivity reactions

Answer

Salicylism

Question 2

Which of the NSAIDs can be administered via the parenteral route?

Accepted Answer

Ketorolac

Answer

Ibuprofen

Answer

Naproxen

Answer

Fenoprofen

Question 3

Muscular rigidity caused by opioids is due to agonistic effect on which receptor?

Accepted Answer

Mu

Answer

Kappa

Answer

Delta

Answer

Sigma

Question 4

Which drugs inhibit the formation of IL-2?

Accepted Answer

Cycloserine

Answer

Cyclosporine

Answer

OKT-3

Answer

Tacrolimus

Question 5

Which of the following is the longest-acting NSAID?

Accepted Answer

Piroxicam

Answer

Aspirin

Answer

Ibuprofen

Answer

Acetaminophen

Question 6

Leflunomide is used in the treatment of which condition?

Accepted Answer

Rheumatoid arthritis

Answer

Dermatomyositis

Answer

Bony metastasis

Answer

Postmenopausal osteoporosis

Question 7

What is the most important side effect of aspirin?

Accepted Answer

Gastritis

Answer

Edema

Answer

Kidney damage

Answer

Hypersensitivity

Question 8

Rofecoxib as compared to indomethacin is:

Accepted Answer

Less likely to cause gastric ulcer and their complications

Answer

Likely to be more effective in rheumatoid arthritis

Answer

Not likely to produce renal complications

Answer

All of the above

Question 9

Which of the following describes the action of allopurinol?

Accepted Answer

Inhibits metabolism of purines to uric acid

Answer

Interferes with cytokine production

Answer

Inhibits uric acid reabsorption

Answer

Inhibits prostaglandin biosynthesis

Question 10

Which of the following opioid analgesics acts primarily through mu opioid receptors?

Accepted Answer

Pentazocine

Answer

Methadone

Answer

Buprenorphine

Answer

Pethidine

Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs — MCQs

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