Analgesics and Anti-inflammatory Drugs Practice Questions

Q: Why do NSAIDs cause gastric ulcers?

They inhibit COX-1 and COX-2 enzymes. ***They inhibit COX-1 and COX-2 enzymes*** - NSAIDs primarily exert their anti-inflammatory effects by inhibiting **cyclooxygenase (COX) enzymes**, specifically COX-1 and COX-2. - While COX-2 inhibition is responsible for anti-inflammatory action, **COX-1 inhibition** reduces the production of protective prostaglandins in the gastric mucosa, leading to a loss of mucosal integrity and an increased risk of ulceration. *They inhibit the production of protective mucus* - While NSAIDs do compromise the gastric mucosal barrier, their primary mechanism is not a direct inhibition of mucus production itself. - Instead, the reduced prostaglandin synthesis indirectly affects the quantity and quality of mucus and bicarbonate, which are crucial for mucosal defense. *They increase gastric acid secretion* - NSAIDs do not directly increase gastric acid secretion; in fact, some studies suggest a mild inhibitory effect. - The main problem is the diminished mucosal protection against the normal levels of gastric acid. *They delay gastric emptying* - Delaying gastric emptying is not a primary mechanism by which NSAIDs cause ulcers. - While some medications can affect gastric motility, this is not the key pathway for NSAID-induced gastropathy.

Q: Which drug is commonly used for outpatient department (OPD) analgesia?

Paracetamol. ***Paracetamol*** - It is a widely used and generally **safe analgesic** and antipyretic often prescribed for mild to moderate pain in an outpatient setting. - Its favorable side effect profile and availability as an **over-the-counter (OTC)** medication make it a first-choice drug for many common pain conditions. *Diclofenac* - While it is an effective NSAID used for pain and inflammation, its use can be associated with **gastrointestinal side effects** like ulcers and bleeding, as well as cardiovascular risks. - It is often reserved for more significant inflammatory pain or when other analgesics are insufficient, and may require more careful monitoring in an outpatient setting. *Ibuprofen* - Similar to diclofenac, Ibuprofen is an **NSAID** which is effective for pain and inflammation. However, it also carries risks of **gastrointestinal irritation** and renal side effects, especially with prolonged use or in certain patient populations. - While available OTC, its use for routine outpatient analgesia may be less preferred than paracetamol in some cases due to its GI and renal side effect profile. *Tramadol* - Tramadol is a **central acting opioid analgesic** with a higher potential for side effects such as nausea, dizziness, constipation, and the risk of dependence or abuse. - It is typically reserved for moderate to severe pain that is not adequately managed by non-opioid analgesics, and its prescription often involves more stringent monitoring than paracetamol.

Q: What is the mode of action of azathioprine?

T-cell blockade. ***T-cell blockade*** - Azathioprine is a **prodrug** that is metabolized into **6-mercaptopurine (6-MP)**, which then interferes with **purine synthesis** [1, 2]. - This interference inhibits the proliferation of **lymphocytes**, particularly **T-cells**, thereby blocking their immune response. *↑ IL-2* - An increase in **IL-2 (interleukin-2)** production would lead to enhanced T-cell proliferation and activity, which is the opposite effect of azathioprine. - **IL-2** is crucial for T-cell growth, differentiation, and survival, so drugs that increase it would boost, not suppress, the immune system. *Decreased lymphophagocytic activity* - This statement is not the primary mode of action of azathioprine. The drug's main effect is on the **synthesis of DNA and RNA** in rapidly dividing cells, including lymphocytes. - While immune suppression can indirectly affect various immune cell functions, the direct mechanism is not primarily a decrease in phagocytosis by lymphocytes. *Wide-spread antitumor activity* - Although 6-mercaptopurine, the active metabolite of azathioprine, is used in combination chemotherapy for some **hematological malignancies**, azathioprine itself is primarily known as an **immunosuppressant** in conditions like **autoimmune diseases** and **transplant rejection**. - Its antitumor activity is not typically described as "wide-spread," and its predominant use in pharmacology is for immune modulation.

Q: Which enzyme is irreversibly inhibited by aspirin?

Cyclooxygenase. ***Cyclooxygenase*** - **Aspirin** irreversibly inhibits **cyclooxygenase (COX-1 and COX-2)** by acetylating a serine residue in the enzyme's active site. - This irreversible inhibition prevents the production of **prostaglandins, thromboxane**, and **prostacyclin**, thereby reducing inflammation, pain, fever, and platelet aggregation. *Lipooxygenase* - **Lipooxygenase** is involved in the synthesis of **leukotrienes**, which are mediators of inflammation and allergic responses. - Aspirin does not directly inhibit lipooxygenase; rather, it primarily targets the COX pathway. *Thromboxane synthase* - **Thromboxane synthase** is an enzyme downstream of COX, responsible for converting prostaglandin H2 into **thromboxane A2**. - While aspirin's effect on platelet aggregation is due to reduced thromboxane A2 synthesis via COX inhibition, it does not directly inhibit thromboxane synthase itself. *Phospholipase* - **Phospholipase A2** is responsible for releasing **arachidonic acid** from cell membrane phospholipids, which is the initial step in both the cyclooxygenase and lipooxygenase pathways. - Aspirin does not directly inhibit phospholipase A2; its action occurs later in the cascade.

Q: What is the classification of Buprenorphine in terms of its action on opioid receptors?

Partial agonist. ***Partial agonist*** - **Buprenorphine** acts as a **partial agonist** at the **mu-opioid receptor**, meaning it binds to the receptor and produces some but not all of the effects of full opioid agonists. - This property contributes to its **ceiling effect** for respiratory depression and analgesic effects, making it safer in overdose compared to full agonists. - It has **high receptor affinity** but **lower intrinsic activity** compared to full agonists. *Pure agonist* - A **pure agonist** would fully activate opioid receptors, producing the maximum possible effect at the receptor. - Examples include **morphine** and **fentanyl**, which carry a higher risk of respiratory depression and overdose at higher doses. - These lack the ceiling effect seen with buprenorphine. *Pure antagonist* - A **pure antagonist** would block opioid receptors without activating them, reversing or preventing the effects of agonists. - An example is **naloxone**, which is used to treat opioid overdose by competitive inhibition. *Mixed agonist-antagonist* - **Mixed agonist-antagonists** (e.g., **pentazocine**, **nalbuphine**) act as agonists at some opioid receptors (kappa) and antagonists at others (mu). - Unlike buprenorphine, which is a partial agonist at mu receptors, mixed agonist-antagonists have different actions at different receptor subtypes. - They can precipitate withdrawal in opioid-dependent patients.

Q: Which of the following nonsteroidal anti-inflammatory drugs (NSAIDs) has good tissue penetrability with a concentration in synovial fluid?

Diclofenac sodium. ***Diclofenac sodium*** - **Diclofenac** is known for its excellent **tissue penetration**, achieving concentrations in **synovial fluid that approach or exceed plasma levels** within hours of administration. - This **rapid and efficient synovial accumulation** makes it particularly effective for **acute inflammatory joint conditions** such as rheumatoid arthritis and osteoarthritis. - Its **favorable pharmacokinetic profile** combines good penetration with relatively rapid onset of action in joint tissues. *Ketorolac* - While a potent NSAID often used for **acute pain management**, ketorolac does not specifically demonstrate superior synovial fluid penetration compared to other NSAIDs. - It has a relatively **short half-life** and is typically limited to **short-term use** (≤5 days) due to increased risk of adverse effects with prolonged administration. *Piroxicam* - **Piroxicam** does achieve good synovial fluid concentrations with a very **long synovial half-life** due to its overall prolonged elimination. - However, the question specifically asks about "good tissue penetrability with concentration," and **diclofenac** is more characteristically cited for its **rapid synovial penetration** and accumulation. - Piroxicam's main advantage is **once-daily dosing** due to its long plasma half-life, rather than superior initial penetration. *Sulindac* - **Sulindac** is a **prodrug** requiring hepatic conversion to its active sulfide metabolite. - Known for potential **renal-sparing effects** in some patients, but does not demonstrate preferential or superior synovial fluid accumulation compared to diclofenac. - Its prodrug nature may result in less predictable synovial fluid concentrations.

Q: Which drug is known to inhibit both cyclooxygenase and lipoxygenase enzymes?

BW755. ***BW755*** - **BW755** is an experimental drug that has been shown to inhibit both the **cyclooxygenase (COX)** and **lipoxygenase (LOX)** pathways. - This dual inhibition prevents the synthesis of both **prostaglandins** and **leukotrienes**, offering a broader anti-inflammatory effect. - Due to dual pathway inhibition, it has theoretical advantages over conventional NSAIDs but is not in clinical use. *Aspirin* - **Aspirin** primarily inhibits **cyclooxygenase (COX) enzymes**, leading to reduced production of **prostaglandins** and **thromboxanes**. - It does not significantly inhibit **lipoxygenase (LOX)** enzymes. - Irreversibly acetylates COX-1 and COX-2. *Indomethacin* - **Indomethacin** is a potent **non-selective COX inhibitor**, reducing the synthesis of **prostaglandins**. - Similar to aspirin, it does not exert significant inhibitory effects on the **lipoxygenase** pathway. - One of the most potent NSAIDs available. *Zileuton* - **Zileuton** is a selective **5-lipoxygenase (5-LOX) inhibitor** used in the management of **asthma**. - It reduces the synthesis of **leukotrienes** (LTC4, LTD4, LTE4) which are mediators of bronchoconstriction and inflammation. - It does **not** inhibit cyclooxygenase enzymes, making it distinct from NSAIDs.

Q: Which of the following anti-gout drugs acts by inhibiting the enzyme xanthine oxidase?

Allopurinol. ***Allopurinol*** - **Allopurinol** is a purine analog that **inhibits xanthine oxidase**, thereby preventing the conversion of hypoxanthine and xanthine to uric acid. - Allopurinol is metabolized to **oxypurinol (alloxanthine)**, which acts as a **competitive inhibitor** of xanthine oxidase. - This action leads to a reduction in **serum uric acid levels**, which is crucial for preventing and treating gout attacks. *Probenecid* - **Probenecid** is a **uricosuric agent** that acts by inhibiting the reabsorption of uric acid in the renal tubules, leading to increased excretion of uric acid in the urine. - It does not affect the production of uric acid by inhibiting xanthine oxidase. *Rasburicase* - **Rasburicase** is a recombinant **uricase enzyme** that catalyzes the oxidation of uric acid to **allantoin**, a more water-soluble compound that is easily excreted by the kidneys. - It is primarily used for the management of **tumor lysis syndrome** and severe hyperuricemia, not by inhibiting xanthine oxidase. *Sulfinpyrazone* - **Sulfinpyrazone** is another **uricosuric agent** similar to probenecid, working by inhibiting the renal tubular reabsorption of uric acid. - Its mechanism of action is distinct from xanthine oxidase inhibition and focuses on enhancing uric acid excretion rather than reducing its production.

Q: Which of the following substances is not classified as an opioid?

Ketamine. ***Ketamine*** - **Ketamine** is classified as a **dissociative anesthetic** and does not act on opioid receptors. - Its primary mechanism of action involves **N-methyl-D-aspartate (NMDA) receptor antagonism**. *Heroin* - **Heroin** (diacetylmorphine) is a **semisynthetic opioid** derived from morphine [1, 3]. - It rapidly crosses the **blood-brain barrier** and is metabolized to morphine, where it acts as a potent **mu-opioid receptor agonist** [3]. *Methadone* - **Methadone** is a **synthetic opioid** used in the treatment of opioid dependence and chronic pain [1, 2]. - It acts primarily as a **mu-opioid receptor agonist** with a long duration of action [1, 2]. *Fentanyl* - **Fentanyl** is a powerful **synthetic opioid** analgesic, much more potent than morphine [2]. - It selectively binds to and activates **mu-opioid receptors**, producing strong analgesic and sedative effects [2].

Q: A patient with hemophilia and rheumatoid arthritis may be prescribed which drug to relieve pain?

Acetaminophen. ***Acetaminophen*** - **Acetaminophen** is a preferred pain reliever for patients with hemophilia because it has **no antiplatelet effect** and thus does not increase the risk of bleeding. - It effectively manages mild to moderate pain associated with **rheumatoid arthritis** without impacting coagulation. *Acetylsalicylic acid* - **Acetylsalicylic acid** (aspirin) is an **NSAID** and a potent **antiplatelet agent**, which would significantly increase the risk of bleeding in a patient with hemophilia. - Its use is contraindicated in hemophilia due to the high risk of **hemorrhage**. *Phenylbutazone* - **Phenylbutazone** is an **NSAID** that is rarely used due to severe side effects such as **aplastic anemia** and **agranulocytosis**. - Like other NSAIDs, it inhibits platelet aggregation, posing a significant **bleeding risk** for hemophiliac patients. *Naproxen* - **Naproxen** is another **NSAID** that inhibits cyclooxygenase enzymes, which not only provides pain relief but also **impairs platelet function**. - Its use is contraindicated in hemophilia because it increases the risk of **gastrointestinal and other bleeding episodes**.

Question 1

Why do NSAIDs cause gastric ulcers?

Accepted Answer

They inhibit COX-1 and COX-2 enzymes

Answer

They increase gastric acid secretion

Answer

They delay gastric emptying

Answer

They inhibit the production of protective mucus

Question 2

Which drug is commonly used for outpatient department (OPD) analgesia?

Accepted Answer

Paracetamol

Answer

Diclofenac

Answer

Ibuprofen

Answer

Tramadol

Question 3

What is the mode of action of azathioprine?

Accepted Answer

T-cell blockade

Answer

↑ IL-2

Answer

Decreased lymphophagocytic activity

Answer

Wide-spread antitumor activity

Question 4

Which enzyme is irreversibly inhibited by aspirin?

Accepted Answer

Cyclooxygenase

Answer

Lipooxygenase

Answer

Thromboxane synthase

Answer

Phospholipase

Question 5

What is the classification of Buprenorphine in terms of its action on opioid receptors?

Accepted Answer

Partial agonist

Answer

Pure agonist

Answer

Pure antagonist

Answer

Mixed agonist-antagonist

Question 6

Which of the following nonsteroidal anti-inflammatory drugs (NSAIDs) has good tissue penetrability with a concentration in synovial fluid?

Accepted Answer

Diclofenac sodium

Answer

Ketorolac

Answer

Piroxicam

Answer

Sulindac

Question 7

Which drug is known to inhibit both cyclooxygenase and lipoxygenase enzymes?

Accepted Answer

BW755

Answer

Aspirin

Answer

Indomethacin

Answer

Zileuton

Question 8

Which of the following anti-gout drugs acts by inhibiting the enzyme xanthine oxidase?

Accepted Answer

Allopurinol

Answer

Rasburicase

Answer

Probenecid

Answer

Sulfinpyrazone

Question 9

Which of the following substances is not classified as an opioid?

Accepted Answer

Ketamine

Answer

Heroin

Answer

Methadone

Answer

Fentanyl

Question 10

A patient with hemophilia and rheumatoid arthritis may be prescribed which drug to relieve pain?

Accepted Answer

Acetaminophen

Answer

Acetylsalicylic acid

Answer

Phenylbutazone

Answer

Naproxen

Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs — MCQs

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