NSAIDs and Enzyme Inhibition Quiz

Questions and Answers

What is a common adverse effect of prolonged use of NSAIDs?

Improved renal function

Sodium and water retention (correct)

Increased urate excretion

Increased appetite

What should be done to minimize gastrointestinal adverse effects of aspirin?

Consume with food (correct)

Take on an empty stomach

Switch to high-dose aspirin

Increase the dosage

Which dose of aspirin is commonly used for anti-inflammatory purposes?

4-6g / day (correct)

50-325mg / day

2-3g / day

1-2g / day

Which of the following is a symptom of acute salicylate poisoning?

Vomiting Signup and view all the answers

Which treatment is NOT indicated for salicylate poisoning?

Increased aspirin dosage Signup and view all the answers

What is the primary effect of salicylates at therapeutic doses related to urate excretion?

Inhibit urate secretion Signup and view all the answers

What is a recommended use of paracetamol?

Antipyretic and analgesic Signup and view all the answers

What is the primary function of COX1?

Biosynthesis of most prostaglandins Signup and view all the answers

In which condition is aspirin preferred for treatment?

Thromboembolic disorders Signup and view all the answers

What role does COX2 play during inflammation?

Inducible during inflammation by cytokines Signup and view all the answers

Which of the following is a function of the prostaglandin PGE2?

Inhibits intraocular pressure (IOP) Signup and view all the answers

Which substances are derived from arachidonic acid through cyclooxygenase and lipoxygenase pathways?

Prostaglandins and thromboxane Signup and view all the answers

Which enzyme is responsible for the conversion of membrane phospholipids to arachidonic acid?

Phospholipase 2 Signup and view all the answers

What is the primary adverse effect of acute paracetamol poisoning?

Hepatotoxicity Signup and view all the answers

Which of the following statements about paracetamol is true?

It is preferred in patients with peptic ulcer. Signup and view all the answers

What antidote is used for paracetamol overdose?

N-acetyl cysteine Signup and view all the answers

Which patient group should avoid aspirin due to increased risks?

Patients with peptic ulcer and bronchial asthma Signup and view all the answers

What metabolite of paracetamol leads to hepatotoxicity when glutathione is depleted?

Toxic metabolite Signup and view all the answers

How does aspirin differ from paracetamol in terms of gastrointestinal effects?

Aspirin causes peptic ulcers and bleeding. Signup and view all the answers

What is a potential consequence of chronic overuse of paracetamol?

Nephrotoxicity Signup and view all the answers

Which statement best describes aspirin’s activity?

It has antiplatelet action. Signup and view all the answers

What is the primary purpose of administering N-acetyl cysteine in paracetamol hepatotoxicity?

To replenish glutathione stores in the liver Signup and view all the answers

In which condition is indomethacin commonly used?

Acute gouty arthritis Signup and view all the answers

What common side effect may occur with the use of triptans?

Injection site reaction Signup and view all the answers

What triggers the onset of a migraine attack in patients?

Hormonal changes Signup and view all the answers

Which population should use triptans with caution?

Pregnant women Signup and view all the answers

Which mechanism does sumatriptan utilize to alleviate migraines?

Activation of 5HT1B/1D receptors Signup and view all the answers

Which treatment is recommended for mild infrequent migraine attacks?

Mild analgesics like NSAIDs Signup and view all the answers

Why might haemodialysis be necessary in cases of paracetamol hepatotoxicity?

To treat acute renal failure Signup and view all the answers

What is the primary pharmacological action of NSAIDs in providing pain relief?

Peripheral inhibition of PGs production Signup and view all the answers

What effect do NSAIDs have on body temperature regulation?

They produce antipyretic effect through sweating Signup and view all the answers

What is a significant risk associated with aspirin use in therapeutic doses?

Gastric mucosa irritation Signup and view all the answers

At high doses, what happens to the antiplatelet effect of aspirin?

It is completely lost Signup and view all the answers

Which of the following mediators can induce COX2 during inflammation?

Cytokines and bradykinin Signup and view all the answers

Study Notes

NSAIDs Overview

NSAIDs cause reversible inhibition of cyclooxygenase (COX) enzymes which synthesize prostaglandins (PGs) from arachidonic acid.
COX-1 is found in most tissues (kidney, platelets, blood vessels, stomach) and regulates normal physiology while COX-2 is inducible during inflammation.

COX Functions

COX-1:
- Responsible for biosynthesis of most PGs (e.g., PGI2, PGE2, TXA2).
- Affects vasodilation, gastric protection, and platelet aggregation.
COX-2:
- Induced by inflammatory mediators in brain and kidney.
- Mediates pain, inflammation, and fever through PGs production.

Pharmacological Actions of NSAIDs

Analgesic: Primarily through peripheral inhibition of PG production.
Antipyretic: Causes vasodilation and sweating.
Anti-inflammatory: High doses provide symptomatic relief; do not alter disease progression.
Antiplatelet: Aspirin irreversibly inhibits platelet aggregation; high doses lose this effect.
Gastric irritation and other gastrointestinal side effects common with aspirin use.

Pharmacokinetics

Salicylates are rapidly absorbed from the gastrointestinal tract, highly bound to plasma proteins, and metabolized in the liver.

Dosage Regimens

Analgesic dose: 2-3g/day in divided doses.
Anti-inflammatory dose: 4-6g/day in divided doses.
Antiplatelet: 50-325mg/day (low dose aspirin).

Adverse Effects

Gastrointestinal: Nausea, vomiting, dyspepsia, gastritis, ulceration, bleeding; minimized by taking after food or using proton pump inhibitors.
Hypersensitivity: Rash, urticaria, bronchospasm, especially with aspirin.
Reye's syndrome: Risk in children receiving salicylates during viral infections.
Pregnancy: Inhibit PG synthesis and delay labor onset.
Analgesic nephropathy: Reversible with drug withdrawal; linked to chronic high-dose use.

Clinical Uses of NSAIDs

Analgesic: Headache, toothache, body pain, dysmenorrhea.
Antipyretic: Paracetamol preferred due to lower gastrointestinal side effects.
Osteoarthritis and rheumatoid arthritis: Manage pain and inflammation without altering disease progression.
Acute rheumatic fever: Aspirin reduces fever and joint pain.
Thromboembolic disorders: Low-dose aspirin reduces risk of stroke and myocardial infarction.
Patent ductus arteriosus (PDA): Indomethacin preferred for closure.

Acute Salicylate Poisoning

Common in children; symptoms include vomiting, dehydration, acid-base imbalance, hyperpnoea, confusion, and possible cardiovascular collapse.

Treatment of Salicylate Poisoning

No specific antidote; symptomatic treatment includes hospitalization and gastric lavage.
IV NaHCO3 corrects metabolic acidosis and alkalinizes urine for enhanced renal excretion.
Haemodialysis may be necessary in severe cases.

Paracetamol

Effective orally and parenterally; metabolized by liver via conjugation.
Uses: Analgesic and antipyretic; safe for patients with peptic ulcers and asthma.
Adverse effects: Hepatotoxicity in overdose; nephrotoxicity with chronic use.

Paracetamol vs. Aspirin

Aspirin: Antipyretic, analgesic, anti-inflammatory; can cause gastric irritation and is contraindicated in certain conditions.
Paracetamol: Analogous effects without gastric irritation; has a specific antidote (N-acetyl cysteine).

Migraine

Initiated by prodromal symptoms and auras, triggered by stress, hormonal changes, sleep disturbances, and alcohol.
Treatment:
- Mild analgesics: NSAIDs and acetaminophen.
- Triptans: Targeted therapy for moderate to severe attacks, acting on selective serotonin receptors.

Ergots

Similar action as triptans; act as 5HT agonists for migraine treatment.

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Description

This quiz explores the mechanisms of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and their reversible inhibition of enzymes such as phospholipase A2 and cyclooxygenase. Test your understanding of arachidonic acid pathways and the roles of lipoxygenase in inflammation. Ideal for students of pharmacology and biochemistry.