Analgesics and Anti-inflammatory Drugs Practice Questions

Q: A patient with rheumatoid arthritis is prescribed a disease-modifying antirheumatic drug (DMARD) that inhibits dihydroorotate dehydrogenase. Which drug is being used?

Leflunomide. ***Leflunomide*** - **Leflunomide** is an immunosuppressive DMARD that inhibits mitochondrial enzyme **dihydroorotate dehydrogenase**, an enzyme crucial for *de novo* pyrimidine synthesis. - This inhibition leads to a reduction in T-cell proliferation and cytokine production, making it effective in treating **rheumatoid arthritis**. *Methotrexate* - **Methotrexate** is a DMARD that primarily works by inhibiting **dihydrofolate reductase**, thus interfering with folate metabolism and purine synthesis. - Its mechanism is distinct from inhibiting dihydroorotate dehydrogenase and involves effects on various inflammatory pathways. *Sulfasalazine* - **Sulfasalazine** is an anti-inflammatory and immunomodulatory drug. Its mechanism of action in rheumatoid arthritis is not fully understood but involves metabolizing into **sulfapyridine** and **5-aminosalicylic acid**. - It does not directly inhibit dihydroorotate dehydrogenase; instead, it may modulate immune cell function and cytokine production. *Hydroxychloroquine* - **Hydroxychloroquine** is an antimalarial drug used in rheumatoid arthritis that inhibits **lysosomal activity** and antigen presentation, and modulates immune responses. - It does not target dihydroorotate dehydrogenase but rather interferes with intracellular signaling and cytokine release.

Q: Pegloticase is used for the treatment of which of the following?

Chronic tophaceous gout. ***Chronic tophaceous gout*** - Pegloticase is a **recombinant pegylated uricase** that metabolizes **uric acid** into allantoin, which is readily excreted by the kidneys. - It is specifically indicated for refractory chronic tophaceous gout when other therapies have failed. *Reactive Arthritis* - This condition is an **autoimmune response** to an infection elsewhere in the body, presenting with aseptic arthritis. - Treatment focuses on managing symptoms with **NSAIDs** and occasionally immune suppressants, not uric acid-lowering agents. *CPPD* - Also known as **pseudogout**, this condition is caused by the deposition of **calcium pyrophosphate dihydrate crystals** in joints. - Treatment involves **NSAIDs**, colchicine, or corticosteroids to manage acute flares, not uric acid-targeted therapies. *Refractory Rheumatoid arthritis* - Rheumatoid arthritis is a chronic inflammatory autoimmune disease primarily affecting the joints. - Treatment involves **DMARDs** (disease-modifying antirheumatic drugs) and biological agents, which target inflammation and immune response, not uric acid.

Q: What is the primary mechanism by which colchicine exerts its anti-inflammatory effects in acute gout?

Acts by inhibiting neutrophil migration. ***Acts by inhibiting neutrophil migration*** - Colchicine primarily functions by **disrupting microtubule formation** in neutrophils, which impairs their chemotaxis and migration to sites of inflammation. - This inhibition of neutrophil activity is crucial in dampening the **inflammatory response** triggered by uric acid crystals in acute gout. *Acts primarily as a uricosuric agent* - While other medications like **probenecid** are uricosuric and increase uric acid excretion, colchicine does not have this primary mechanism of action. - Its main anti-inflammatory effect is independent of uric acid metabolism or excretion. *Is the first-line treatment for chronic gout management* - Colchicine is effective for **acute gout attacks** and as a prophylactic against attacks during initiation of urate-lowering therapy. - However, **allopurinol** and **febuxostat** are the first-line treatments for chronic gout because they reduce uric acid production. *Has no effect on microtubule function* - This statement is incorrect; colchicine's entire mechanism of action is dependent on its ability to **bind to tubulin** and inhibit microtubule polymerization. - This disruption of microtubules is responsible for its anti-inflammatory effects and also its common side effects.

Q: Which of the following is a naturally occurring opioid?

Morphine. ***Morphine*** - **Morphine** is a naturally occurring **opioid alkaloid** found in the **opium poppy** (Papaver somniferum). - It is one of the most potent **analgesics** and is widely used for severe pain. *Ethylmorphine* - **Ethylmorphine** is a **semisynthetic opioid** derived from morphine by **ethylation**. - It is currently used primarily as an **antitussive** (cough suppressant). *Pholcodeine* - **Pholcodeine** is a **semisynthetic opioid** that acts as a **cough suppressant**. - It works by depressing the **cough reflex** in the brainstem. *Diacetylmorphine* - **Diacetylmorphine**, commonly known as **heroin**, is a **semisynthetic opioid** synthesized from morphine. - It is highly potent and rapidly crosses the **blood-brain barrier**, producing intense effects.

Q: Rasburicase is a recombinant form of which enzyme?

Urate Oxidase. ***Urate Oxidase*** - **Rasburicase** is a recombinant **urate oxidase** enzyme that catalyzes the oxidation of uric acid into allantoin. - This conversion makes uric acid more soluble and easier to excrete, thereby lowering serum uric acid levels, which is crucial in managing or preventing **tumor lysis syndrome** [2]. *Xanthine oxidase* - **Xanthine oxidase** is involved in the catabolism of purines, converting xanthine to uric acid [1]. - **Allopurinol**, a common drug for hyperuricemia, inhibits xanthine oxidase, but rasburicase does not act as an analogue or inhibitor of this enzyme [3], [4]. *IMP dehydrogenase* - **IMP dehydrogenase** is an enzyme involved in the de novo synthesis of guanine nucleotides from inosine monophosphate (IMP). - It is not directly involved in the catabolism of uric acid, and rasburicase has no known functional analogy to it. *Adenosine Deaminase* - **Adenosine deaminase** is an enzyme that catalyzes the deamination of adenosine to inosine. - Its deficiency is associated with a severe combined immunodeficiency (SCID), and it plays no direct role in uric acid metabolism related to rasburicase's action.

Q: Which of the following is the most potent opioid?

Sufentanil. ***Sufentanil*** - **Sufentanil** is a very potent synthetic opioid, estimated to be 5 to 10 times more potent than fentanyl and 500 to 1000 times more potent than morphine. - Its high potency is due to its strong binding affinity for **mu-opioid receptors** and rapid onset of action. *Butorphanol* - **Butorphanol** is a mixed opioid agonist-antagonist, acting as a partial agonist or antagonist at mu-opioid receptors and an agonist at kappa-opioid receptors. - While it provides analgesia, its efficacy is limited compared to full agonists due to its mixed receptor profile. *Pentazocine* - **Pentazocine** is another mixed opioid agonist-antagonist, primarily a kappa-opioid receptor agonist and a weak mu-opioid receptor antagonist or partial agonist. - It has a lower analgesic ceiling and can precipitate withdrawal in patients dependent on full mu-opioid agonists. *Hydrocodone* - **Hydrocodone** is an opioid agonist primarily used for moderate to severe pain, typically found in combination with acetaminophen. - Its potency is comparable to morphine, making it significantly less potent than ultra-potent synthetic opioids like sufentanil.

Q: Which T cell surface molecule's co-stimulatory function is blocked by Abatacept?

CD28. ***CD28*** - **Abatacept** is a fusion protein that binds to **CD80** and **CD86** on antigen-presenting cells (APCs). - This binding prevents the interaction of **CD80/CD86** with **CD28** on T cells, thereby blocking the critical co-stimulatory signal required for full T-cell activation [1]. *CD11* - **CD11** is part of the **integrin** family (e.g., CD11b/CD18, known as Mac-1 or CR3) and is involved in cell adhesion and migration, primarily on myeloid cells. - It does not directly participate in the **T-cell co-stimulation pathway** targeted by abatacept. *CD20* - **CD20** is a B-cell specific surface molecule that is the target of **rituximab**, a monoclonal antibody used in various lymphomas and autoimmune diseases. - It is not expressed on T cells and therefore not involved in **T-cell co-stimulation** blocked by abatacept. *CD22* - **CD22** is a **B-cell co-receptor** molecule involved in B-cell activation and signaling, acting as a negative regulator. - It does not play a direct role in the **co-stimulatory signals** between APCs and T cells that are modulated by abatacept.

Q: Tocilizumab acts as an antagonist at which receptor?

IL-6. ***Correct: IL-6*** - **Tocilizumab** is a **monoclonal antibody** that specifically targets the **IL-6 receptor**, blocking the binding of **interleukin-6 (IL-6)** and inhibiting its pro-inflammatory effects. - This mechanism makes it effective in treating inflammatory conditions like **rheumatoid arthritis**, **giant cell arteritis**, and **cytokine release syndrome**. *Incorrect: IL-1* - **IL-1 antagonists**, such as **anakinra**, target the **IL-1 receptor** to block the inflammatory actions of **interleukin-1**. - These are typically used for conditions like **rheumatoid arthritis** and **cryopyrin-associated periodic syndromes (CAPS)**, distinct from tocilizumab's mechanism. *Incorrect: IL-2* - **IL-2 receptor antagonists**, such as **basiliximab** and **daclizumab**, are primarily used to prevent **organ transplant rejection** by inhibiting **T-cell activation**. - Their mechanism is different from **tocilizumab**, which targets a different cytokine pathway. *Incorrect: TNF-alpha* - **TNF-alpha inhibitors**, like **adalimumab** or **infliximab**, block the activity of **tumor necrosis factor-alpha**, a key cytokine in inflammation. - These agents are widely used for diseases such as **rheumatoid arthritis**, **psoriasis**, and **Crohn's disease**, but they operate on a different pathway than tocilizumab.

Q: Which of the following statements about local anesthetics is FALSE?

Prilocaine is less toxic than lignocaine. ***Prilocaine is less toxic than lignocaine*** - This statement is **false**. While prilocaine has a lower incidence of central nervous system (CNS) toxicity compared to lidocaine, it is associated with a higher risk of **methemoglobinemia**, especially at higher doses, which makes it potentially more toxic in specific scenarios. - Overall, the safety profile of prilocaine, particularly regarding its potential for methemoglobinemia, does not necessarily make it "less toxic" than lignocaine; they have different toxicity profiles. *Lidocaine is shorter acting than bupivacaine* - This statement is **true**. **Lidocaine** is an intermediate-acting local anesthetic, with a duration of action typically ranging from 30 minutes to 3 hours, depending on the dose and presence of a vasoconstrictor. - **Bupivacaine** is a long-acting local anesthetic, with effects lasting 4-8 hours due to its high lipid solubility and protein binding. *Mixture of lignocaine and prilocaine is known as eutectic* - This statement is **true**. A mixture of lidocaine (lignocaine) and prilocaine is known as an **Eutectic Mixture of Local Anesthetics (EMLA)**. - The word "eutectic" refers to the specific proportion of these two substances that results in a lower melting point than either drug individually, allowing them to exist as a liquid at room temperature. This formulation is used for topical anesthesia. *Lignocaine is used as an antiarrhythmic* - This statement is **true**. **Lidocaine (lignocaine)** is a **Class IB antiarrhythmic** drug. - It works by blocking cardiac sodium channels, thereby stabilizing the myocardial cell membrane and decreasing automaticity, making it effective in treating ventricular arrhythmias, especially after myocardial infarction.

Question 1

A patient with rheumatoid arthritis is prescribed a disease-modifying antirheumatic drug (DMARD) that inhibits dihydroorotate dehydrogenase. Which drug is being used?

Accepted Answer

Leflunomide

Answer

Methotrexate

Answer

Sulfasalazine

Answer

Hydroxychloroquine

Question 2

A patient with severe cancer pain is on high-dose morphine but is experiencing uncontrolled pain and side effects. What is the best next step?

Accepted Answer

Switch to methadone for its NMDA receptor antagonism

Answer

Add a non-steroidal anti-inflammatory drug (NSAID)

Answer

Increase the morphine dose and monitor side effects

Answer

Discontinue morphine and switch to fentanyl

Question 3

Pegloticase is used for the treatment of which of the following?

Accepted Answer

Chronic tophaceous gout

Answer

Reactive Arthritis

Answer

CPPD

Answer

Refractory Rheumatoid arthritis

Question 4

What is the primary mechanism by which colchicine exerts its anti-inflammatory effects in acute gout?

Accepted Answer

Acts by inhibiting neutrophil migration

Answer

Acts primarily as a uricosuric agent

Answer

Is the first-line treatment for chronic gout management

Answer

Has no effect on microtubule function

Question 5

Which of the following is a naturally occurring opioid?

Accepted Answer

Morphine

Answer

Pholcodeine

Answer

Ethylmorphine

Answer

Diacetylmorphine

Question 6

Rasburicase is a recombinant form of which enzyme?

Accepted Answer

Urate Oxidase

Answer

Xanthine oxidase

Answer

IMP dehydrogenase

Answer

Adenosine Deaminase

Question 7

Which of the following is the most potent opioid?

Accepted Answer

Sufentanil

Answer

Butorphanol

Answer

Pentazocine

Answer

Hydrocodone

Question 8

Which T cell surface molecule's co-stimulatory function is blocked by Abatacept?

Accepted Answer

CD28

Answer

CD11

Answer

CD20

Answer

CD22

Question 9

Tocilizumab acts as an antagonist at which receptor?

Accepted Answer

IL-6

Answer

IL-1

Answer

IL-2

Answer

TNF-alpha

Question 10

Which of the following statements about local anesthetics is FALSE?

Accepted Answer

Prilocaine is less toxic than lignocaine

Answer

Lidocaine is shorter acting than bupivacaine

Answer

Mixture of lignocaine and prilocaine is known as eutectic

Answer

Lignocaine is used as an antiarrhythmic

Analgesics and Anti-inflammatory Drugs — MCQs

Analgesics and Anti-inflammatory Drugs — MCQs

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