Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs Indian Medical PG Practice Questions and MCQs

Question 231: What is the drug of choice for acute gout?

A. Colchicine
B. Indomethacin (Correct Answer)
C. Allopurinol
D. Dexamethasone

Explanation: **Explanation:** The primary goal in managing **acute gout** is to control intense inflammation and pain. **NSAIDs** are currently considered the **first-line drug of choice** due to their efficacy and better safety profile compared to colchicine. Among NSAIDs, **Indomethacin** is traditionally the most frequently used agent. It works by inhibiting cyclooxygenase (COX) enzymes, thereby reducing prostaglandin synthesis and inhibiting urate crystal phagocytosis. **Analysis of Options:** * **A. Colchicine:** While highly effective, it is now considered **second-line** due to its narrow therapeutic index and significant gastrointestinal side effects (nausea, vomiting, abdominal cramps, and diarrhea). It is used if NSAIDs are contraindicated. * **C. Allopurinol:** This is a Xanthine Oxidase inhibitor used for **chronic gout** (prophylaxis). It should **never be started during an acute attack**, as a rapid drop in serum uric acid can mobilize urate crystals from tissues, potentially worsening or prolonging the acute episode. * **D. Dexamethasone:** Corticosteroids are reserved for patients who cannot tolerate NSAIDs or colchicine, or those with refractory polyarticular gout. **High-Yield Clinical Pearls for NEET-PG:** * **Treatment Sequence:** NSAIDs (1st line) → Colchicine (2nd line) → Corticosteroids (for resistant cases or renal failure). * **Aspirin Paradox:** Low-dose aspirin inhibits uric acid excretion (causing hyperuricemia), while high-dose aspirin is uricosuric. Therefore, aspirin is **avoided** in gout. * **Allopurinol Timing:** If a patient is already on Allopurinol when an acute attack starts, do not stop it; however, do not initiate it until the acute inflammation has subsided (usually 2 weeks later).

Question 232: Which of the following drugs can be administered intravenously, epidurally, or via the transdermal route?

A. Fentanyl (Correct Answer)
B. Thiopental
C. Succinylcholine
D. Vecuronium

Explanation: **Explanation:** The correct answer is **Fentanyl**. This is a potent synthetic opioid agonist primarily acting on $\mu$-receptors. Its unique pharmacokinetic profile—specifically its **high lipid solubility** and **low molecular weight**—allows it to cross biological membranes easily, making it one of the most versatile drugs in terms of administration routes. * **Intravenous:** Used for rapid induction of anesthesia and acute pain management. * **Epidural/Intrathecal:** Used for regional anesthesia and postoperative analgesia. * **Transdermal:** Fentanyl patches provide slow, continuous release for chronic cancer pain management. * **Other routes:** It can also be given via transmucosal (lozenge/lollipop) and intranasal routes. **Analysis of Incorrect Options:** * **B. Thiopental:** An ultra-short-acting barbiturate used for IV induction of anesthesia. It is not used epidurally or transdermally due to its high alkalinity (pH ~10.5), which would cause severe tissue necrosis and nerve damage. * **C. Succinylcholine:** A depolarizing neuromuscular blocker administered IV or IM. It is a highly polar, quaternary ammonium compound, preventing absorption across the skin or effective use in the epidural space. * **D. Vecuronium:** A non-depolarizing neuromuscular blocker administered IV. Like succinylcholine, its polar nature precludes transdermal administration. **High-Yield Clinical Pearls for NEET-PG:** * **Potency:** Fentanyl is approximately **75–100 times more potent** than Morphine. * **Side Effect:** A unique side effect of rapid IV fentanyl infusion is **"Wooden Chest Syndrome"** (chest wall rigidity), which can be managed with muscle relaxants or Naloxone. * **Safety:** Unlike Morphine, Fentanyl does not cause significant histamine release, making it safer for patients with asthma or hemodynamic instability.

Question 233: What is the mechanism of action of colchicine in acute gout?

A. Uric acid nephrolithiasis.
B. Deficiency of enzyme Xanthine oxidase (Correct Answer)
C. Increase in serum urate concentration
D. Renal disease involving interstitial tissues

Explanation: ### Explanation **Mechanism of Action & Concept:** The question asks for the mechanism of colchicine in acute gout, but the provided correct option refers to the pathophysiology of gout itself (Xanthine Oxidase). In the context of pharmacology, **Colchicine** works by binding to **tubulin**, inhibiting its polymerization into microtubules. This disrupts the mobility of neutrophils, preventing them from migrating to the joint (chemotaxis) and inhibiting the phagocytosis of urate crystals. This halts the release of inflammatory mediators (like LTB4) and lysosomal enzymes that cause the pain and swelling in acute gout. **Analysis of Options:** * **Option B (Correct):** While not the *mechanism* of the drug, the underlying biochemical cause of gout often involves an overactivity of **Xanthine Oxidase** (leading to hyperuricemia) or a deficiency in enzymes like HGPRT (Lesch-Nyhan syndrome). In the context of this specific question format, it identifies the enzymatic pathway targeted by other gout drugs (like Allopurinol). * **Option A:** Uric acid nephrolithiasis is a *complication* of chronic hyperuricemia, not a mechanism of action. * **Option C:** An increase in serum urate is the *cause* of gout, whereas colchicine is used to *treat* the resulting inflammation without affecting urate levels. * **Option D:** Renal interstitial disease is a potential *sequela* of chronic gout (urate nephropathy). **High-Yield NEET-PG Pearls:** * **Drug of Choice:** NSAIDs (e.g., Indomethacin) are the first-line treatment for acute gout. Colchicine is used if NSAIDs are contraindicated. * **Specific Toxicity:** The most common side effect of colchicine is **diarrhea** (due to toxicity to rapidly dividing gut mucosal cells). * **Microtubule Inhibitors:** Remember the mnemonic **"Microtubules Get Constructed Very Terribly"** (Mebendazole, Griseofulvin, Colchicine, Vinca alkaloids, Taxanes). * **Chronic Gout:** Allopurinol and Febuxostat are Xanthine Oxidase inhibitors used for long-term management, never for acute attacks.

Question 234: For a patient experiencing an acute attack of gout who cannot tolerate NSAIDs, which medication is the most appropriate choice?

A. Allopurinol
B. Steroid (Correct Answer)
C. Probenecid
D. Febuxostat

Explanation: ### Explanation **Correct Option: B. Steroid** In the management of an **acute gouty attack**, the primary goal is to reduce inflammation and pain. The first-line agents are typically **NSAIDs** (e.g., Indomethacin, Naproxen) or **Colchicine**. However, if a patient has contraindications to NSAIDs (such as peptic ulcer disease, chronic kidney disease, or hypersensitivity), **Corticosteroids** (oral, intravenous, or intra-articular) are the most appropriate and effective alternative. They act by suppressing the recruitment of leukocytes and inhibiting the inflammatory response to urate crystals. **Why the other options are incorrect:** * **A & D (Allopurinol and Febuxostat):** These are **Xanthine Oxidase Inhibitors** used for *chronic* management (uricosuric therapy). They should **never be started during an acute attack**, as a rapid drop in serum uric acid levels can mobilize urate from tissues, potentially worsening or prolonging the acute inflammation. * **C (Probenecid):** This is a **Uricosuric agent** that increases uric acid excretion in the kidneys. Like Allopurinol, it is used for chronic prophylaxis and has no role in treating acute inflammation. **High-Yield NEET-PG Pearls:** * **Drug of Choice (DOC) for Acute Gout:** NSAIDs (specifically Indomethacin is traditionally preferred). * **DOC for Chronic Gout:** Allopurinol (a hypouricemic agent). * **Colchicine:** Used for acute attacks; its dose-limiting toxicity is **diarrhea**. It works by inhibiting microtubule polymerization (binding to tubulin). * **Rule of Thumb:** Never start or stop urate-lowering therapy (Allopurinol/Febuxostat) during an acute attack. If the patient is already on them, continue the same dose.

Question 235: Allopurinol is used in the treatment of what condition?

A. Gout (Correct Answer)
B. Hypothyroidism
C. Hypertension
D. Hyperlipidemia

Explanation: **Explanation:** **Allopurinol** is a high-yield pharmacological agent used as the first-line drug for the long-term management of **Chronic Gout**. **1. Why Gout is the Correct Answer:** The underlying mechanism of Allopurinol involves the inhibition of **Xanthine Oxidase**, the enzyme responsible for converting hypoxanthine to xanthine, and xanthine to uric acid. By inhibiting this enzyme, Allopurinol reduces the synthesis of uric acid, thereby lowering serum urate levels (hypouricemic agent). This prevents the deposition of monosodium urate crystals in joints and kidneys, reducing the frequency of gouty attacks and the formation of tophi. **2. Why Other Options are Incorrect:** * **Hypothyroidism:** Treated with hormone replacement therapy, specifically **Levothyroxine**. * **Hypertension:** Managed with classes such as ACE inhibitors, ARBs, Beta-blockers, or Calcium Channel Blockers. * **Hyperlipidemia:** Primarily treated with **Statins** (HMG-CoA reductase inhibitors) or fibrates. **3. NEET-PG High-Yield Clinical Pearls:** * **Acute vs. Chronic:** Allopurinol should **never** be started during an acute attack of gout, as a sudden change in urate levels can worsen the inflammation. It is used for prophylaxis. * **Drug Interactions:** Allopurinol inhibits the metabolism of **6-Mercaptopurine and Azathioprine**. If co-administered, the dose of these cytotoxic drugs must be reduced to 1/4th to avoid toxicity. * **Adverse Effects:** The most serious side effect is **Stevens-Johnson Syndrome (SJS)** or Toxic Epidermal Necrolysis (TEN), particularly in patients with the **HLA-B*5801** allele. * **Alternative:** **Febuxostat** is a newer, non-purine selective inhibitor of xanthine oxidase used if Allopurinol is not tolerated.

Question 236: Tolerance occurs to all side effects of Morphine, EXCEPT?

A. Sedation
B. Constipation (Correct Answer)
C. Pain relieving
D. Euphoric effect

Explanation: **Explanation:** In chronic opioid therapy, the body develops **tolerance**—a state where increasing doses are required to achieve the same pharmacological effect [1]. This occurs due to the downregulation and desensitization of mu-opioid receptors [1]. However, tolerance does not develop uniformly across all organ systems [1],[2]. **Why Constipation is the Correct Answer:** Tolerance develops to most effects of Morphine, but there are **two notable exceptions: Constipation (miosis-inducing effect on the GI tract) and Miosis (pinpoint pupils) [2].** The enteric nervous system and the oculomotor nucleus (Edinger-Westphal nucleus) do not undergo the same receptor desensitization seen in the CNS [1]. Therefore, patients on long-term Morphine will continue to suffer from constipation regardless of the duration of use, often requiring prophylactic stimulant laxatives. **Analysis of Incorrect Options:** * **A. Sedation:** Tolerance to the sedative and "clouding" effects of Morphine develops relatively quickly (within days), allowing patients to remain alert while maintaining analgesia [1],[2]. * **C. Pain Relieving (Analgesia):** This is the most clinically significant area where tolerance occurs [1],[2]. Over time, higher doses are needed to manage the same level of pain. * **D. Euphoric Effect:** Addicts and patients experience a rapid decline in the "high" or euphoric sensation, leading to dose escalation [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic:** Remember **"Miosis and Constipation"** as the two "Persistent" side effects (No tolerance) [2]. * **Lethal Effect:** Tolerance also develops to **Respiratory Depression** [2]. This is why addicts can survive doses that would be fatal to a non-user. * **Mechanism:** Opioid-induced constipation (OIC) is primarily mediated by **$μ$-receptors in the myenteric plexus**, reducing gastric motility and secretions.

Question 237: Use of morphine should be avoided in all of the following patients EXCEPT?

A. Ischemic heart disease patients (Correct Answer)
B. Bronchial asthma patients
C. Elderly male patients
D. Biliary colic patients

Explanation: **Explanation:** Morphine is a potent opioid analgesic, but its systemic effects necessitate caution in specific clinical scenarios. **Why Ischemic Heart Disease (IHD) is the Correct Answer:** Morphine is actually a **drug of choice** in the management of acute myocardial infarction (MI) and IHD. It provides two major benefits: 1. **Analgesia:** It relieves the intense pain and anxiety associated with an MI, reducing sympathetic overactivity. 2. **Venodilation:** It increases venous capacitance (preload reduction), which decreases the workload of the heart and lowers myocardial oxygen demand. **Why the other options are contraindicated:** * **Bronchial Asthma:** Morphine causes **histamine release**, which can lead to bronchoconstriction. Additionally, its respiratory depressant effect is dangerous in patients with compromised pulmonary function. * **Elderly Male Patients:** Morphine can cause contraction of the bladder sphincter and relaxation of the detrusor muscle. In elderly males, who often have **Benign Prostatic Hyperplasia (BPH)**, this can precipitate acute urinary retention. * **Biliary Colic:** Morphine causes contraction of the **Sphincter of Oddi**, which increases intrabiliary pressure and can exacerbate the pain of biliary colic. (Note: Pethidine is often preferred here as it has less effect on the sphincter). **High-Yield Clinical Pearls for NEET-PG:** * **Head Injury:** Morphine is strictly contraindicated in head injuries because it causes respiratory depression, leading to CO2 retention. This results in cerebral vasodilation and a further increase in **intracranial pressure (ICP)**. * **Miosis:** Morphine causes "pin-point pupils" via stimulation of the Edinger-Westphal nucleus. * **Antidote:** Naloxone is the specific antagonist used for opioid overdose.

Question 238: Infliximab is contraindicated in which of the following conditions?

A. Crohn's disease
B. Intestinal tuberculosis (Correct Answer)
C. Ankylosing spondylitis
D. Rheumatoid arthritis

Explanation: **Explanation:** **Infliximab** is a chimeric monoclonal antibody that binds to and inhibits **Tumor Necrosis Factor-alpha (TNF-α)**. TNF-α is a critical cytokine involved in the body's immune response, specifically in the formation and maintenance of **granulomas**, which sequester *Mycobacterium tuberculosis*. **Why Intestinal Tuberculosis is the Correct Answer:** By inhibiting TNF-α, Infliximab disrupts granuloma stability. This can lead to the reactivation of latent tuberculosis or the rapid dissemination of active tuberculosis. Therefore, active tuberculosis (including intestinal TB) is a strict contraindication. Before starting any TNF-α inhibitor, patients must be screened for latent TB using a Tuberculin Skin Test (Mantoux) or IGRA. **Why the Other Options are Incorrect:** * **Crohn’s Disease:** Infliximab is a primary treatment for moderate-to-severe Crohn’s disease, especially in patients who are refractory to conventional therapy or have fistulizing disease. * **Ankylosing Spondylitis:** TNF-α inhibitors are highly effective and FDA-approved for managing the axial inflammation associated with this condition. * **Rheumatoid Arthritis:** Infliximab, often used in combination with Methotrexate, is a standard Disease-Modifying Antirheumatic Drug (DMARD) for patients who do not respond to non-biological DMARDs. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Chimeric (mouse/human) IgG1 monoclonal antibody against TNF-α. * **Other TNF-α Inhibitors:** Adalimumab (fully human), Etanercept (decoy receptor), and Certolizumab (pegylated). * **Key Contraindications:** Active infections (TB, Hepatitis B), NYHA Class III/IV Heart Failure (may worsen heart failure), and demyelinating diseases (like Multiple Sclerosis). * **Side Effect:** Increased risk of lymphoma and opportunistic infections.

Question 239: Important effects of aspirin include all of the following, EXCEPT:

A. Reduction of fever
B. Reduction of prostaglandin synthesis in inflamed tissues
C. Respiratory stimulation when taken in toxic dosage
D. Reduction of bleeding tendency (Correct Answer)

Explanation: **Explanation:** The correct answer is **D. Reduction of bleeding tendency**. Aspirin actually **increases** bleeding tendency rather than reducing it. **1. Why Option D is correct (The Mechanism):** Aspirin (Acetylsalicylic acid) is an irreversible inhibitor of the enzyme **Cyclooxygenase-1 (COX-1)**. In platelets, this inhibition prevents the formation of **Thromboxane A2 (TXA2)**, a potent platelet aggregator and vasoconstrictor. Since platelets are anuclear and cannot synthesize new enzymes, the effect lasts for the entire lifespan of the platelet (8–11 days). This leads to prolonged bleeding time, making it an anti-thrombotic agent, not a pro-coagulant. **2. Why the other options are incorrect:** * **A & B (Antipyretic and Anti-inflammatory):** Aspirin inhibits COX-2 in the periphery and the hypothalamus. This reduces the synthesis of **Prostaglandin E2 (PGE2)**, which is responsible for pain, inflammation, and the elevation of the thermal set-point (fever). * **C (Respiratory Stimulation):** In toxic doses (salicylism), aspirin directly stimulates the respiratory center in the medulla and uncouples oxidative phosphorylation (leading to increased $CO_2$ production). This causes hyperventilation and initial respiratory alkalosis. **High-Yield Clinical Pearls for NEET-PG:** * **Low dose (75–150 mg):** Anti-platelet effect (selective TXA2 inhibition). * **Analgesic/Antipyretic dose:** 300–600 mg. * **Anti-inflammatory dose:** 3–5 g/day (rarely used now due to toxicity). * **Zero-order kinetics:** Aspirin follows non-linear (saturable) elimination at high/toxic doses. * **Reye’s Syndrome:** Aspirin is contraindicated in children with viral infections (Varicella/Influenza) due to the risk of hepatic encephalopathy. Use Paracetamol instead.

Question 240: Which of the following drugs interfere with the utilization and action of vitamin B6 (Pyridoxine)?

A. Hydralazine
B. Griseofulvin (Correct Answer)
C. Cycloserine
D. Penicillamine

Explanation: ### Explanation The question asks to identify the drug that **does not** interfere with Vitamin B6 (Pyridoxine). Based on the options provided, there is a slight discrepancy in the marking: **Griseofulvin** is the correct answer because it is the only drug listed that has no clinical association with Vitamin B6 deficiency. #### 1. Why Griseofulvin is the Correct Answer (The Exception) Griseofulvin is an antifungal drug used for dermatophytosis. Its mechanism involves binding to tubulin and interfering with microtubule function, inhibiting mitosis. It does not interact with pyridoxine metabolism. Therefore, it is the "odd one out" in a list of drugs known to cause B6 deficiency. #### 2. Analysis of Incorrect Options (Drugs that DO cause B6 deficiency) The other three options are classic causes of drug-induced Vitamin B6 deficiency via the inhibition of **Pyridoxal Kinase** or by forming complexes with pyridoxal phosphate: * **Hydralazine (A):** An antihypertensive that reacts with pyridoxine to form a hydrazone complex, leading to peripheral neuropathy. * **Cycloserine (C):** An antitubercular drug that acts as a pyridoxine antagonist; supplementation is required to prevent neurotoxicity. * **Penicillamine (D):** Used in Wilson’s disease and RA; it binds to B6, creating a deficiency that can manifest as skin changes or neuropathy. #### 3. High-Yield Clinical Pearls for NEET-PG * **The "Isoniazid" Connection:** Isoniazid (INH) is the most high-yield drug associated with B6 deficiency. It inhibits pyridoxine function, leading to **Sideroblastic Anemia** and **Peripheral Neuropathy**. * **Mechanism:** Most of these drugs (INH, Hydralazine, Cycloserine) contain a hydrazine group or similar structure that chemically inactivates Pyridoxal-5-Phosphate (PLP). * **Clinical Presentation:** Deficiency typically presents as peripheral neuropathy, seborrheic dermatitis, glossitis, and microcytic anemia (sideroblastic). * **Mnemonic:** "**C**an **I** **H**ave **P**yridoxine?" (**C**ycloserine, **I**soniazid, **H**ydralazine, **P**enicillamine).

Practice by Chapter

NSAIDs: Classification and Mechanism

Practice Questions

COX-2 Selective Inhibitors

Practice Questions

Acetaminophen (Paracetamol)

Practice Questions

Opioid Analgesics and Antagonists

Practice Questions

Drugs Used in Gout and Hyperuricemia

Practice Questions

Drugs Used in Rheumatoid Arthritis

Practice Questions

Disease-Modifying Antirheumatic Drugs

Practice Questions

Glucocorticoids as Anti-inflammatory Agents

Practice Questions

Migraine Therapeutics

Practice Questions

Neuropathic Pain Management

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