Analgesics and Anti-inflammatory Drugs Practice Questions

Q: Pethidine is pharmacologically different from morphine because it

Has additional Anticholinergic action. Pethidine (Meperidine) is a synthetic opioid that differs from Morphine due to its unique chemical structure, which resembles Atropine. This structural similarity imparts significant **anticholinergic (antimuscarinic) properties** to Pethidine, which are absent in Morphine [2]. **Why Option C is Correct:** The additional anticholinergic action of Pethidine leads to several clinical differences: * **Mydriasis:** Unlike Morphine, which causes "pin-point pupils" (miosis), Pethidine can cause pupillary dilation or maintain a normal pupil size. * **Tachycardia:** It may cause an increase in heart rate, whereas Morphine typically causes bradycardia [2]. * **Dry Mouth:** Patients often experience more xerostomia. **Analysis of Incorrect Options:** * **A. Sedation:** Pethidine is generally **less sedating** than Morphine. At high doses or with chronic use, its metabolite (normeperidine) can cause CNS excitation, tremors, and seizures. * **B. Constipation:** Pethidine causes **less constipation** and has a shorter duration of action on the gastrointestinal tract compared to Morphine [1]. * **D. Spasm of Sphincter of Oddi:** While Pethidine does cause some contraction of smooth muscles, it causes **less spasm** of the Sphincter of Oddi than Morphine. Historically, this made it the preferred opioid for biliary colic (though NSAIDs are now first-line). **High-Yield Clinical Pearls for NEET-PG:** 1. **Metabolite Danger:** Pethidine is metabolized to **Normeperidine** [1], which is neurotoxic. It can cause **seizures**, especially in patients with renal failure [2]. 2. **Drug Interaction:** Pethidine is strictly contraindicated with **MAO Inhibitors** (e.g., Selegiline) as it can trigger a life-threatening **Serotonin Syndrome** (hyperpyrexia, delirium, convulsions). 3. **Obstetrics:** Pethidine is often preferred in labor because it does not delay uterine contractions as much as Morphine.

Q: Cyclosporine in nephrotic syndrome acts by which mechanism?

Inhibiting calcineurin. **Explanation:** **Cyclosporine** is a potent immunosuppressant used in steroid-resistant or steroid-dependent nephrotic syndrome. Its primary mechanism of action is the **inhibition of calcineurin**, a calcium-dependent phosphatase. 1. **Mechanism of Action:** Cyclosporine binds to an intracellular protein called **cyclophilin**. This complex then inhibits calcineurin, preventing the dephosphorylation and activation of the **Nuclear Factor of Activated T-cells (NFAT)**. Consequently, the transcription of IL-2 and other cytokines is blocked, leading to decreased T-cell activation. 2. **Podocyte Stabilization:** Beyond immunosuppression, Cyclosporine has a direct non-immunological effect on the kidney. It stabilizes the **actin cytoskeleton of podocytes** by preventing the calcineurin-mediated degradation of **synaptopodin**, thereby reducing proteinuria. **Analysis of Incorrect Options:** * **Option B (Inhibition of GMPD):** This refers to **Mycophenolate Mofetil (MMM)**, which inhibits Inosine Monophosphate Dehydrogenase (IMPDH), a rate-limiting step in guanosine nucleotide (GMP) synthesis. * **Option C (Alkylating agent):** This describes drugs like **Cyclophosphamide** and Chlorambucil, which work by cross-linking DNA strands. * **Option D (Antibiotic):** While some immunosuppressants are derived from fungi/bacteria (e.g., Sirolimus is a macrolide), Cyclosporine is classified as a Calcineurin Inhibitor (CNI), not an antibiotic. **High-Yield Clinical Pearls for NEET-PG:** * **Side Effects of Cyclosporine:** Gingival hyperplasia, hirsutism, nephrotoxicity (afferent arteriolar vasoconstriction), and hypertension. * **Tacrolimus** is another CNI (binds to FKBP-12) but is more potent and does not cause hirsutism or gingival hyperplasia (though it has a higher risk of post-transplant diabetes). * **Monitoring:** Therapeutic Drug Monitoring (TDM) is essential for Cyclosporine due to its narrow therapeutic index.

Q: Which one of the following drugs is NOT a non-opioid analgesic?

Methadone. **Explanation:** The classification of analgesics is a high-yield topic for NEET-PG. Analgesics are broadly divided into two categories: **Non-opioids** (NSAIDs and Acetaminophen) and **Opioids** (Narcotics). **Why Methadone is the correct answer:** **Methadone** is a potent **synthetic opioid agonist** that acts primarily on $\mu$-opioid receptors. Unlike NSAIDs, it does not inhibit cyclooxygenase (COX) enzymes. It is clinically unique because it also acts as an NMDA receptor antagonist and inhibits the reuptake of serotonin and norepinephrine. It is primarily used for detoxification and maintenance treatment of opioid abstinence syndromes (heroin addiction) and for chronic pain management due to its long half-life. **Why the other options are incorrect:** * **Meloxicam:** A selective **COX-2 inhibitor** belonging to the oxicam class of NSAIDs. It is a classic non-opioid analgesic used for osteoarthritis and rheumatoid arthritis. * **Nimesulide:** A preferential **COX-2 inhibitor**. It is a non-opioid analgesic frequently used for acute pain, though its use is restricted in some regions due to potential hepatotoxicity. * **Nabumetone:** A **non-acidic NSAID** (prodrug) that is converted into its active metabolite in the liver. It is a non-opioid analgesic known for having a lower incidence of GI side effects compared to traditional NSAIDs. **NEET-PG High-Yield Pearls:** * **Methadone's Half-life:** It has a very long and variable half-life (15–60 hours), which can lead to cumulative toxicity. * **NMDA Antagonism:** Methadone’s ability to block NMDA receptors makes it effective for neuropathic pain where other opioids might fail. * **EKG Monitoring:** Methadone is notorious for causing **QT interval prolongation** and *Torsades de Pointes*; baseline EKG is recommended.

Q: Ibuprofen is contraindicated in which of the following patient groups?

Patients with asthma. Explanation: The correct answer is **B. Patients with asthma**. **Mechanism of Action:** Ibuprofen is a non-selective Non-Steroidal Anti-Inflammatory Drug (NSAID) that inhibits the enzyme **Cyclooxygenase (COX)** [2]. In the body, Arachidonic acid is metabolized via two main pathways: the COX pathway (producing prostaglandins) and the **Lipoxygenase (LOX) pathway** (producing leukotrienes). When NSAIDs like Ibuprofen inhibit the COX pathway, the metabolism of Arachidonic acid is "shunted" toward the LOX pathway. This leads to an overproduction of **Cysteinyl Leukotrienes (LTC4, LTD4, LTE4)**, which are potent bronchoconstrictors [3]. In susceptible individuals, this triggers **NSAID-Exacerbated Respiratory Disease (NERD)**, characterized by bronchospasm, airway inflammation, and rhinitis. **Analysis of Incorrect Options:** * **A. Fever:** Ibuprofen is an effective antipyretic and is commonly used to treat fever. * **C. Amoebic Dysentery:** This is an intestinal infection caused by *E. histolytica*. While NSAIDs are generally avoided in severe GI inflammation due to gastric irritation [1], there is no specific contraindication related to the pathology of amoebiasis. * **D. Bronchitis:** This is an inflammation of the bronchial tubes (often viral). Unlike asthma, it does not typically involve the leukotriene-sensitive hyperreactivity that leads to NSAID-induced bronchospasm. **High-Yield Clinical Pearls for NEET-PG:** * **Samter’s Triad (Aspirin-Exacerbated Respiratory Disease):** Consists of Asthma, Aspirin sensitivity, and Nasal polyps. * **Safe Alternative:** **Paracetamol (Acetaminophen)** is generally considered the analgesic of choice in asthmatic patients as it is a weak peripheral COX inhibitor [2]. * **Other Contraindications for NSAIDs:** Peptic ulcer disease, chronic kidney disease (CKD), and severe heart failure [1].

Q: Which of the following is an injectable COX-2 inhibitor?

Parecoxib. **Explanation:** **Parecoxib** is the correct answer because it is a **prodrug of Valdecoxib** and is currently the only selective COX-2 inhibitor available for **parenteral (injectable)** administration. It is rapidly converted by liver enzymes into its active form, Valdecoxib. It is primarily used in hospital settings for the short-term management of acute postoperative pain when oral medication is not feasible. **Analysis of Incorrect Options:** * **Celecoxib (Option A):** This is the prototype selective COX-2 inhibitor. It is administered strictly via the **oral route** and is commonly used for chronic conditions like osteoarthritis and rheumatoid arthritis. * **Etoricoxib (Option B):** This is a second-generation selective COX-2 inhibitor with a long half-life, allowing for once-daily dosing. Like Celecoxib, it is only available in **oral formulations**. * **None of the above (Option D):** This is incorrect as Parecoxib serves as the specific injectable representative of this class. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Selective COX-2 inhibitors lack the anti-platelet effects of non-selective NSAIDs (as they do not inhibit COX-1/TXA2) and carry a lower risk of GI ulcers. * **Contraindication:** All selective COX-2 inhibitors (including Parecoxib) are contraindicated in patients with **Ischemic Heart Disease (IHD)** or stroke due to an increased risk of thrombotic cardiovascular events. * **Sulfonamide Allergy:** Celecoxib contains a sulfonamide moiety; use caution in patients with sulfa allergies. * **Rofecoxib/Valdecoxib:** These were withdrawn globally due to high cardiovascular toxicity.

Q: A 54-year-old obese man diagnosed with NIDDM one year ago is on glipizide and metformin. He also takes propranolol and nifedipine for hypertension, and recently started naproxen for severe osteoarthritis. His current BP is 154/92. His BUN is 29 mg/dL and creatinine is 1.8 mg/dL, both of which were normal one year prior. Which medication is most likely responsible for the increase in BUN and creatinine?

Naproxen. ### Explanation The correct answer is **Naproxen**. #### 1. Why Naproxen is the Correct Answer Naproxen is a Non-Steroidal Anti-Inflammatory Drug (NSAID) [1]. NSAIDs inhibit the enzyme cyclooxygenase (COX), leading to decreased synthesis of **prostaglandins** (specifically PGE2 and PGI2). In the kidneys, prostaglandins are essential for maintaining renal blood flow by causing **vasodilation of the afferent arteriole** [1]. In patients with underlying risk factors (diabetes, hypertension, or older age), the inhibition of these vasodilatory prostaglandins leads to afferent arteriolar vasoconstriction. This reduces the glomerular filtration rate (GFR), resulting in **Prerenal Azotemia**, characterized by an increase in Blood Urea Nitrogen (BUN) and Creatinine. #### 2. Why the Other Options are Incorrect * **Glipizide (Sulfonylurea):** Primarily causes hypoglycemia and weight gain; it does not have direct nephrotoxic effects. * **Metformin (Biguanide):** While metformin must be dose-adjusted or discontinued in renal failure to prevent **lactic acidosis**, it does not *cause* the rise in creatinine itself. * **Nifedipine (Calcium Channel Blocker):** CCBs are generally neutral or protective regarding renal hemodynamics and do not cause acute elevations in BUN/Creatinine. #### 3. NEET-PG High-Yield Pearls * **Triple Whammy:** Be cautious of the "Triple Whammy" effect on the kidney: **NSAIDs** (constrict afferent arteriole) + **ACE inhibitors/ARBs** (dilate efferent arteriole) + **Diuretics** (reduce plasma volume). This combination significantly increases the risk of Acute Kidney Injury (AKI). * **Analgesic Nephropathy:** Chronic use of NSAIDs can lead to **Chronic Interstitial Nephritis** and **Renal Papillary Necrosis** [1]. * **Metformin Guideline:** In NEET-PG, remember that Metformin is contraindicated if the eGFR is <30 mL/min/1.73m² due to the risk of lactic acidosis.

Q: All of the following statements are true except?

Cyclooxygenase-I (COX-I) is an inducible enzyme.. ### Explanation The correct answer is **B**, as Cyclooxygenase-I (COX-1) is a **constitutive** enzyme, not an inducible one. **1. Why Option B is the Correct Answer (The False Statement):** In the arachidonic acid cascade, COX enzymes exist in two primary isoforms. **COX-1** is "constitutive," meaning it is expressed constantly in most tissues (e.g., stomach lining, kidneys, and platelets). It serves "housekeeping" functions like gastric cytoprotection and maintaining renal blood flow. In contrast, **COX-2** is the "inducible" isoform, synthesized primarily in response to inflammatory stimuli, cytokines, and growth factors. **2. Analysis of Other Options:** * **Option A:** True. Arachidonic acid, released from membrane phospholipids by Phospholipase A2, serves as the common precursor for both prostaglandins (via the COX pathway) and leukotrienes (via the LOX pathway). * **Option C:** True. COX-2 expression is triggered at sites of injury by pro-inflammatory mediators like Interleukin-1 (IL-1) and Tumor Necrosis Factor (TNF). * **Option D:** True. Cysteinyl leukotrienes (LTC4, LTD4, LTE4) are potent bronchoconstrictors and are significantly more powerful than histamine in inducing airway smooth muscle contraction. **3. NEET-PG High-Yield Clinical Pearls:** * **Aspirin:** Irreversibly inhibits COX-1 and COX-2 via acetylation. * **Selective COX-2 Inhibitors (e.g., Celecoxib):** Provide anti-inflammatory effects with a lower risk of gastric ulcers but carry an increased risk of cardiovascular events (due to inhibition of PGI2 without affecting TXA2). * **Platelets:** Contain only COX-1; since they lack a nucleus, they cannot regenerate the enzyme once inhibited. * **Glucocorticoids:** Inhibit inflammation by inducing *annexins*, which inhibit Phospholipase A2, and by repressing the expression of COX-2.

Q: Etanercept is a biological disease-modifying agent used in the management of rheumatoid arthritis. What is its mechanism of action?

TNF alpha blockade. ### Explanation **Correct Option: A. TNF alpha blockade** Etanercept is a biological Disease-Modifying Anti-Rheumatic Drug (bDMARD). It is a **soluble decoy receptor** consisting of two extracellular domains of the human TNF receptor (p75) fused to the Fc portion of human IgG1. It works by binding to both **TNF-α** and **TNF-β** (lymphotoxin-alpha) in the circulation, preventing them from interacting with cell-surface receptors. This neutralizes the pro-inflammatory cascade responsible for joint destruction in rheumatoid arthritis. **Analysis of Incorrect Options:** * **B. COX-2 inhibition:** This is the mechanism of NSAIDs like Celecoxib and Etoricoxib. While they provide symptomatic relief by reducing prostaglandin synthesis, they do not modify the disease progression. * **C. IL-6 inhibition:** This describes **Tocilizumab** and **Sarilumab**. These agents target the IL-6 receptor rather than TNF. * **D. Stabilization of mast cells:** This is the mechanism of drugs like Sodium Cromoglycate and Ketotifen, used primarily in the management of asthma and allergic rhinitis. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic:** Remember **"Etanercept intercepts TNF"** (it acts as a decoy). * **Screening:** Before starting any TNF inhibitor (Etanercept, Infliximab, Adalimumab), patients must be screened for **Latent Tuberculosis** (using PPD or IGRA) because TNF is essential for granuloma maintenance. * **Other Indications:** Apart from RA, it is used in Psoriatic Arthritis and Ankylosing Spondylitis. * **Distinction:** Unlike Infliximab (a monoclonal antibody), Etanercept is a **fusion protein**.

Q: Which drug blocks both H1 and 5-HT2 receptors?

Cyproheptadine. **Explanation:** **Cyproheptadine** is a first-generation antihistamine with a unique pharmacological profile. It acts as a potent antagonist at both **H1 (histamine)** receptors and **5-HT2 (serotonin)** receptors. This dual blockade is the underlying medical concept that makes it effective for specific clinical conditions beyond simple allergies. **Analysis of Options:** * **Cyproheptadine (Correct):** Its anti-serotonergic action (5-HT2 blockade) makes it the drug of choice for treating **Serotonin Syndrome**. Its H1-blocking property contributes to its sedative effects and its use in treating allergic rhinitis and urticaria. * **Phenoxybenzamine:** This is a non-selective, irreversible **alpha-adrenergic blocker** used primarily in the management of pheochromocytoma. It does not have significant H1 or 5-HT2 activity. * **Ritanserin:** This is a selective **5-HT2 receptor antagonist**. While it shares the serotonin-blocking property of cyproheptadine, it lacks significant H1 receptor antagonism. * **Ondansetron:** This is a selective **5-HT3 receptor antagonist** used primarily as an anti-emetic. It does not block H1 or 5-HT2 receptors. **High-Yield Clinical Pearls for NEET-PG:** * **Serotonin Syndrome:** Cyproheptadine is the specific antidote/management drug. * **Appetite Stimulation:** Due to its 5-HT2 antagonism in the hypothalamus, cyproheptadine is used off-label as an appetite stimulant in children and patients with failure to thrive. * **Cushing’s Disease:** It was historically used to reduce ACTH secretion (via serotonin inhibition), though it is rarely used for this now. * **Dumping Syndrome:** It can be used to manage post-gastrectomy dumping syndrome due to its anti-serotonergic effects.

Question 1

Pethidine is pharmacologically different from morphine because it

Accepted Answer

Has additional Anticholinergic action

Answer

Causes more sedation

Answer

Causes more constipation

Answer

Causes spasm of sphincter of Oddi

Question 2

Cyclosporine in nephrotic syndrome acts by which mechanism?

Accepted Answer

Inhibiting calcineurin

Answer

Inhibition of GMPD

Answer

Acting as an alkylating agent

Answer

Acting as an antibiotic

Question 3

Which one of the following drugs is NOT a non-opioid analgesic?

Accepted Answer

Methadone

Answer

Meloxicam

Answer

Nimesulide

Answer

Nabumetone

Question 4

Ibuprofen is contraindicated in which of the following patient groups?

Accepted Answer

Patients with asthma

Answer

Patients with fever

Answer

Patients with amoebic dysentery

Answer

Patients with bronchitis

Question 5

Which of the following is an injectable COX-2 inhibitor?

Accepted Answer

Parecoxib

Answer

Celecoxib

Answer

Etoricoxib

Answer

None of the above

Question 6

A 54-year-old obese man diagnosed with NIDDM one year ago is on glipizide and metformin. He also takes propranolol and nifedipine for hypertension, and recently started naproxen for severe osteoarthritis. His current BP is 154/92. His BUN is 29 mg/dL and creatinine is 1.8 mg/dL, both of which were normal one year prior. Which medication is most likely responsible for the increase in BUN and creatinine?

Accepted Answer

Naproxen

Answer

Glipizide

Answer

Metformin

Answer

Nifedipine

Question 7

All of the following statements are true except?

Accepted Answer

Cyclooxygenase-I (COX-I) is an inducible enzyme.

Answer

Prostaglandins and leukotrienes are derived from arachidonic acid.

Answer

Cyclooxygenase-II (COX-II) is induced by cytokines at sites of inflammation.

Answer

Leukotrienes cause smooth muscle constriction.

Question 8

Etanercept is a biological disease-modifying agent used in the management of rheumatoid arthritis. What is its mechanism of action?

Accepted Answer

TNF alpha blockade

Answer

COX-2 inhibition

Answer

IL-6 inhibition

Answer

Stabilization of mast cells

Question 9

Which drug blocks both H1 and 5-HT2 receptors?

Accepted Answer

Cyproheptadine

Answer

Phenoxybenzamine

Answer

Ritanserin

Answer

Ondansetron

Question 10

Which of the following statements about Pentazocine is false?

Accepted Answer

Has a higher risk of addiction than morphine.

Answer

Causes decreased vomiting and constipation compared to morphine.

Answer

Has a lower risk of addiction than morphine.

Answer

Acts as an agonist-antagonist.

Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs — MCQs

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