Analgesics and Anti-inflammatory Drugs Practice Questions

Q: Which of the following is not a DMARD in the treatment of rheumatoid arthritis?

Corticosteroids. **Explanation:** The core concept in treating Rheumatoid Arthritis (RA) is the distinction between drugs that provide symptomatic relief and those that modify the disease process. **Disease-Modifying Anti-Rheumatic Drugs (DMARDs)** are agents that slow down disease progression, prevent joint destruction, and reduce radiological damage. **Why Corticosteroids is the correct answer:** While corticosteroids (like Prednisolone) are potent anti-inflammatory agents used to provide rapid symptomatic relief and "bridge" the gap until DMARDs become effective, they are **not** classified as DMARDs. They do not fundamentally arrest the long-term progression of the disease or prevent joint deformity when used alone. Chronic use is also limited by significant systemic toxicity. **Analysis of incorrect options:** * **A. Methotrexate:** The "Gold Standard" and first-line DMARD. It acts by inhibiting dihydrofolate reductase and increasing adenosine levels, which suppresses inflammation and joint damage. * **B. Leflunomide:** A prodrug that inhibits the enzyme dihydroorotate dehydrogenase, leading to decreased pyrimidine synthesis. It is a potent DMARD often used as an alternative to Methotrexate. * **D. Penicillamine:** A conventional (synthetic) DMARD. Though rarely used today due to toxicity (like proteinuria and myasthenia-like syndrome), it historically belongs to the DMARD category. **High-Yield Clinical Pearls for NEET-PG:** * **Classification:** DMARDs are divided into **csDMARDs** (Conventional Synthetic: Methotrexate, Sulfasalazine, Hydroxychloroquine, Leflunomide) and **bDMARDs** (Biologicals: TNF-inhibitors like Etanercept, Infliximab). * **Fastest acting DMARD:** Sulfasalazine. * **Slowest acting DMARD:** Hydroxychloroquine (takes 3–6 months). * **Methotrexate Monitoring:** Requires supplementation with Folic acid to reduce GI and mucosal side effects. It is contraindicated in pregnancy (Teratogenic).

Q: Which drug is used for the treatment of acute gout?

Indomethacin. **Explanation:** The primary goal in treating **acute gout** is to control pain and inflammation. **Indomethacin**, a potent Non-Steroidal Anti-inflammatory Drug (NSAID), is the traditional drug of choice for acute attacks. It works by inhibiting cyclooxygenase (COX) enzymes, thereby reducing the synthesis of prostaglandins that mediate pain and swelling in the joint. **Analysis of Options:** * **Indomethacin (Correct):** It is highly effective in terminating an acute gouty attack. Other NSAIDs like Naproxen or Diclofenac are also used, but Indomethacin remains the classic textbook answer. * **Aspirin (Incorrect):** Aspirin is contraindicated in gout. At low doses, it inhibits the tubular secretion of uric acid, leading to **hyperuricemia**, which can worsen or prolong an attack. * **Allopurinol & Febuxostat (Incorrect):** These are **hypouricemic agents** (Xanthine Oxidase Inhibitors) used for **chronic gout** (prophylaxis). They should never be started during an acute attack because a rapid drop in serum urate levels can cause the mobilization of urate crystals from tissues, paradoxically worsening the acute inflammation. **High-Yield Clinical Pearls for NEET-PG:** * **First-line for Acute Gout:** NSAIDs (e.g., Indomethacin) are first-line. If NSAIDs are contraindicated (e.g., peptic ulcer, renal failure), **Colchicine** or **Glucocorticoids** are used. * **Colchicine Mechanism:** It inhibits microtubule assembly by binding to tubulin, thereby preventing neutrophil migration to the joint. * **The "Wait" Rule:** Never start or stop Allopurinol during an acute attack. Wait 2–4 weeks after the attack has subsided before initiating urate-lowering therapy.

Q: What type of opioid receptor agonist is Buprenorphine?

Partial agonist. **Buprenorphine** is classified as a **Partial Mu ($\\mu$) Opioid Receptor Agonist** and a **Kappa ($\\kappa$) Opioid Receptor Antagonist** [2]. 1. **Why Option C is correct:** As a partial agonist, buprenorphine has high affinity for the $\\mu$-receptor but low intrinsic activity (efficacy) [1]. This results in a **"Ceiling Effect"**—beyond a certain dose, increasing the amount of drug does not increase the analgesic effect or respiratory depression [1, 3]. This makes it safer in overdose compared to full agonists [1]. 2. **Why Option A is incorrect:** Pure agonists (e.g., Morphine, Fentanyl) have high intrinsic activity and no ceiling effect on respiratory depression. 3. **Why Option B is incorrect:** Pure antagonists (e.g., Naloxone, Naltrexone) bind to the receptor but produce no biological response; they are used to reverse opioid effects. **High-Yield Clinical Pearls for NEET-PG:** * **Opioid Substitution Therapy:** Due to its long duration of action and slow dissociation from $\\mu$-receptors, it is used in treating opioid dependence (detoxification and maintenance) [3]. * **Precipitated Withdrawal:** If given to a patient already dependent on a full agonist (like Heroin), buprenorphine can displace the full agonist and trigger withdrawal symptoms due to its lower intrinsic activity. * **Route:** It undergoes extensive first-pass metabolism, so it is typically administered **sublingually** or via transdermal patches [3]. * **Reversibility:** Because it binds so tightly to receptors, higher-than-normal doses of Naloxone are required to reverse its effects in case of toxicity [3].

Q: Naltrexone is:

Mu receptor antagonist. **Explanation:** **Naltrexone** is a potent, long-acting **pure opioid antagonist**. It works by competitively binding to opioid receptors with a very high affinity, thereby blocking the effects of endogenous and exogenous opioids. While it acts on Mu, Kappa, and Delta receptors, its primary clinical effect is mediated through the **antagonism of Mu (μ) receptors**. * **Why Option D is correct:** Naltrexone blocks the Mu receptor, preventing the euphoria and physical dependence associated with opioid use. Unlike Naloxone (which is used for acute overdose), Naltrexone has high oral bioavailability and a long half-life (approx. 10 hours), making it ideal for maintenance therapy. * **Why Options A, B, and C are incorrect:** Naltrexone does not activate (agonize) any opioid receptors. An agonist would produce morphine-like effects (analgesia, sedation, respiratory depression). Naltrexone specifically lacks intrinsic activity; it only occupies the receptor to prevent agonist binding. **Clinical Pearls for NEET-PG:** 1. **Indications:** Used for the **prevention of relapse** in detoxified opioid addicts and for **Alcohol Dependence** (it reduces alcohol craving by blocking the reward pathways mediated by endogenous opioids). 2. **Naltrexone vs. Naloxone:** Remember the mnemonic **"Nal-O-xone is for Overdose"** (IV/Intranasal, short-acting) and **"Naltrexone is for Maintenance"** (Oral, long-acting). 3. **Contraindication:** It should never be given to a patient currently dependent on opioids without detoxification, as it will precipitate **acute withdrawal syndrome**. 4. **Vivitrol:** This is the extended-release injectable form of Naltrexone given once monthly.

Q: Buprenorphine is a partial agonist of which receptor?

Mu receptor. **Explanation:** **Buprenorphine** is a unique semi-synthetic opioid derivative. It is classified as a **partial Mu (μ) receptor agonist** [2] and a **Kappa (κ) receptor antagonist**. 1. **Why Mu receptor is correct:** Buprenorphine binds with high affinity but low intrinsic activity to the Mu receptor [2], [3]. This results in a "ceiling effect" for respiratory depression and euphoria [1], making it safer in overdose compared to full agonists like morphine. However, due to its high binding affinity, it can displace full agonists, potentially precipitating withdrawal in opioid-dependent individuals [3]. 2. **Why other options are incorrect:** * **Kappa (κ) receptor:** Buprenorphine acts as an **antagonist** at this receptor. This antagonism is clinically significant as it contributes to its antidepressant effects and lack of psychotomimetic side effects (like dysphoria) typically associated with Kappa agonists. * **Delta (δ) receptor:** Buprenorphine has relatively low affinity/activity here; it is primarily considered an antagonist at Delta receptors. * **Sigma (σ) receptor:** This is no longer classified as a true opioid receptor. It is associated with hallucinations and dysphoria (seen with drugs like Pentazocine), but it is not the primary site of action for Buprenorphine. **High-Yield Clinical Pearls for NEET-PG:** * **Ceiling Effect:** Buprenorphine exhibits a ceiling effect for respiratory depression, enhancing its safety profile [1]. * **Opioid Substitution Therapy:** It is used in the management of opioid addiction (detoxification and maintenance) [1]. * **Naloxone Resistance:** Because Buprenorphine dissociates very slowly from Mu receptors, respiratory depression caused by it is difficult to reverse with standard doses of Naloxone [1]. * **Route:** It undergoes extensive first-pass metabolism, so it is administered **sublingually**, parenterally, or via transdermal patches [1].

Q: Aspirin inhibits which of the following enzymes?

Cyclooxygenase. **Explanation:** **Mechanism of Action (Why C is correct):** Aspirin (Acetylsalicylic acid) is a Non-Steroidal Anti-Inflammatory Drug (NSAID) that acts by **irreversibly inhibiting the Cyclooxygenase (COX-1 and COX-2) enzymes**. It achieves this by covalently attaching an acetyl group to a serine residue at the active site of the enzyme. This blockade prevents the conversion of arachidonic acid into pro-inflammatory mediators, specifically **Prostaglandins, Prostacyclin, and Thromboxane A2 (TXA2)**. **Analysis of Incorrect Options:** * **A. Lipoprotein lipase:** This enzyme is responsible for the hydrolysis of triglycerides in chylomicrons and VLDLs. It is not a target for NSAIDs. * **B. Lipooxygenase (LOX):** This enzyme converts arachidonic acid into Leukotrienes. While some newer drugs (like Zileuton) target this pathway, Aspirin does not inhibit LOX. In fact, by blocking the COX pathway, Aspirin can "shunt" arachidonic acid toward the LOX pathway, potentially leading to **Aspirin-Exacerbated Respiratory Disease (AERD)** or "Aspirin Asthma." * **D. Phospholipase:** Phospholipase A2 is the enzyme that releases arachidonic acid from membrane phospholipids. This enzyme is inhibited by **Corticosteroids** (via lipocortin/annexin A1), not Aspirin. **High-Yield Clinical Pearls for NEET-PG:** * **Irreversibility:** Aspirin is the only NSAID that inhibits COX enzymes **irreversibly**. * **Antiplatelet Effect:** Because platelets cannot synthesize new proteins, the inhibition of COX-1 (and subsequent TXA2 production) lasts for the entire lifespan 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 (like Varicella or Influenza) due to the risk of fulminant hepatic failure and encephalopathy.

Q: Phenylbutazone use as an NSAID is restricted because:

It has potential to cause agranulocytosis.. **Explanation:** **1. Why Option B is Correct:** Phenylbutazone is a pyrazolone derivative that was once widely used for its potent anti-inflammatory properties. However, its clinical use is now severely restricted (primarily to severe cases of ankylosing spondylitis or acute gout unresponsive to other treatments) due to its **idiosyncratic bone marrow toxicity**. The most serious adverse effect is **agranulocytosis** (and occasionally aplastic anemia), which can be fatal. Unlike dose-dependent side effects, this reaction is unpredictable and can occur even with short-term use, making the risk-benefit ratio unfavorable compared to newer NSAIDs. **2. Why Other Options are Incorrect:** * **Option A & C:** These are incorrect because Phenylbutazone is actually a **very potent** anti-inflammatory and analgesic agent. Its efficacy is comparable to or higher than many modern NSAIDs; the restriction is purely due to safety concerns, not lack of potency. * **Option D:** While Phenylbutazone does indeed cause significant drug interactions by displacing drugs (like warfarin or sulfonylureas) from plasma proteins and inhibiting their metabolism, this is a manageable clinical concern. It is not the primary reason for the near-total restriction of the drug; the life-threatening hematological toxicity (Option B) is the deciding factor. **3. High-Yield Clinical Pearls for NEET-PG:** * **Metabolite:** Oxyphenbutazone is the active metabolite of Phenylbutazone. * **Uricosuric Action:** Phenylbutazone has mild uricosuric properties, which is why it was historically used in gout. * **Sodium Retention:** It causes significant salt and water retention, making it contraindicated in patients with heart failure or hypertension. * **Exam Tip:** Whenever "Phenylbutazone" or "Metamizole (Analgin)" appears in NEET-PG, always look for **Agranulocytosis** as the key associated side effect.

Q: Mechanism of action of aspirin is inhibition of:

Thromboxane A2 synthesis. **Explanation:** **Aspirin (Acetylsalicylic Acid)** is a non-selective Non-Steroidal Anti-inflammatory Drug (NSAID) that acts by **irreversibly inhibiting** the enzymes Cyclooxygenase-1 (COX-1) and COX-2 [1], [2]. It achieves this by acetylating a specific serine residue at the active site of the enzyme [2]. In platelets, COX-1 is responsible for the production of **Thromboxane A2 (TXA2)**, a potent vasoconstrictor and platelet aggregator. Since platelets are anucleated and cannot synthesize new enzymes, the inhibition lasts for the entire lifespan of the platelet (approx. 7–10 days). This makes aspirin an effective antiplatelet agent for the prophylaxis of myocardial infarction and stroke [3]. **Analysis of Incorrect Options:** * **B. Phosphodiesterase (PDE):** Inhibited by drugs like Sildenafil (PDE-5), Milrinone (PDE-3), or Theophylline (non-selective). * **C. HMG-CoA Reductase:** This is the rate-limiting enzyme in cholesterol synthesis, inhibited by **Statins** (e.g., Atorvastatin). * **D. Pancreatic Lipase:** Inhibited by **Orlistat**, an anti-obesity drug that prevents the absorption of dietary fats. **High-Yield Clinical Pearls for NEET-PG:** * **Zero-order kinetics:** Aspirin follows first-order kinetics at low doses but shifts to zero-order kinetics at anti-inflammatory/toxic doses. * **Reye’s Syndrome:** Aspirin is contraindicated in children with viral infections (Varicella/Influenza) due to the risk of hepatic encephalopathy. * **Samter’s Triad:** Aspirin-exacerbated respiratory disease (AERD) consisting of asthma, nasal polyps, and aspirin sensitivity. * **Toxicity:** Salicylism presents with **tinnitus** (earliest sign), respiratory alkalosis, and metabolic acidosis. Management involves urinary alkalinization.

Q: Which of the following drugs is useful in chronic gout but is NOT a uricosuric agent?

Allopurinol. ### Explanation **Correct Answer: D. Allopurinol** **1. Why Allopurinol is Correct:** Chronic gout is managed by lowering serum uric acid levels through two primary mechanisms: decreasing production or increasing excretion. **Allopurinol** is a **Xanthine Oxidase inhibitor**. It works by inhibiting the enzyme responsible for converting hypoxanthine to xanthine and xanthine to uric acid. Therefore, it reduces the *synthesis* of uric acid rather than increasing its renal excretion. It is the first-line drug for chronic gout, especially in "over-producers" of uric acid. **2. Why Other Options are Incorrect:** * **Probenecid (A):** This is a classic **uricosuric agent**. It inhibits the URAT1 transporter in the proximal convoluted tubule, blocking the reabsorption of uric acid and increasing its excretion in urine. * **Sulfinpyrazone (C):** Like probenecid, this is a potent **uricosuric agent** that inhibits renal tubular reabsorption of uric acid. * **Phenylbutazone (B):** This is an NSAID with weak uricosuric properties. While it has anti-inflammatory effects, it is rarely used today due to toxicity (e.g., agranulocytosis), but it technically falls into the category of drugs that increase uric acid excretion. **3. NEET-PG High-Yield Pearls:** * **Drug of Choice:** Allopurinol is the DOC for chronic gout in patients with renal impairment or a history of renal stones (where uricosurics are contraindicated). * **Hypersensitivity:** Watch for **HLA-B*5801** allele; patients with this gene are at high risk for Allopurinol Hypersensitivity Syndrome (SJS/TEN). * **Acute Attack Warning:** Never start Allopurinol during an acute attack of gout, as a sudden drop in serum urate can mobilize crystals from joints and worsen the inflammation. * **Drug Interaction:** Allopurinol inhibits the metabolism of **6-Mercaptopurine** and **Azathioprine**. If co-administered, the dose of these cytotoxic drugs must be reduced by 75%.

Question 1

Which of the following is not a DMARD in the treatment of rheumatoid arthritis?

Accepted Answer

Corticosteroids

Answer

Methotrexate

Answer

Leflunomide

Answer

Penicillamine

Question 2

Which drug is used for the treatment of acute gout?

Accepted Answer

Indomethacin

Answer

Aspirin

Answer

Febuxostat

Answer

Allopurinol

Question 3

What type of opioid receptor agonist is Buprenorphine?

Accepted Answer

Partial agonist

Answer

Pure agonist

Answer

Pure antagonist

Answer

None of the above

Question 4

Naltrexone is:

Accepted Answer

Mu receptor antagonist

Answer

Mu receptor agonist

Answer

Delta receptor agonist

Answer

Kappa receptor agonist

Question 5

Buprenorphine is a partial agonist of which receptor?

Accepted Answer

Mu receptor

Answer

Delta receptor

Answer

Kappa receptor

Answer

Sigma receptor

Question 6

Serum Lithium level is increased by all the following drugs EXCEPT?

Accepted Answer

Verapamil

Answer

Aspirin

Answer

Chlorthiazide

Answer

Tetracycline

Question 7

Aspirin inhibits which of the following enzymes?

Accepted Answer

Cyclooxygenase

Answer

Lipoprotein lipase

Answer

Lipooxygenase

Answer

Phospholipase d

Question 8

Phenylbutazone use as an NSAID is restricted because:

Accepted Answer

It has potential to cause agranulocytosis.

Answer

It has lower anti-inflammatory efficacy than other NSAIDs.

Answer

It has weak analgesic action.

Answer

It alters the protein binding and metabolism of many drugs.

Question 9

Mechanism of action of aspirin is inhibition of:

Accepted Answer

Thromboxane A2 synthesis

Answer

Phosphodiesterase

Answer

HMG-CoA reductase

Answer

Pancreatic lipase

Question 10

Which of the following drugs is useful in chronic gout but is NOT a uricosuric agent?

Accepted Answer

Allopurinol

Answer

Probenecid

Answer

Phenylbutazone

Answer

Sulfinpyrazone

Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs — MCQs

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