Pharmwar

Answer: C) Elderly patient with kidney disease Explanation: Ibuprofen and other NSAIDs can worsen kidney function by reducing blood flow to the kidneys, especially in older adults or those with existing kidney impairment (CKD stage 3 or worse). Alternative pain relievers like acetaminophen are safer for these patients. The other options describe appropriate uses with proper dosing.

Answer: B) Blood thinners like warfarin Explanation: Ibuprofen increases bleeding risk with anticoagulants through multiple mechanisms: it inhibits platelets, irritates the stomach lining, and can displace warfarin from proteins in the blood. This combination requires close monitoring and often alternative pain relievers. Even with stomach protectors, the bleeding risk remains significant.

Answer: C) It temporarily inhibits platelets Explanation: Ibuprofen reversibly blocks COX-1 in platelets, causing short-term (1-2 hour) inhibition of clot formation. Aspirin's effect is irreversible, lasting the platelet's entire 7-10 day lifespan. Importantly, taking ibuprofen can interfere with aspirin's heart-protective effects if dosed too close together.

Answer: B) 2400 mg Explanation: The FDA recommends not exceeding 2400 mg per day (typically 800 mg every 8 hours) for prescription-strength dosing. Over-the-counter use is usually limited to 1200 mg daily. Higher doses don't provide additional pain relief but significantly increase risks of stomach ulcers, kidney damage, and cardiovascular problems. The analgesic effect plateaus around 400 mg per dose.

Answer: B) The S-enantiomer Explanation: Only the S-isomer of ibuprofen (dexibuprofen) actively inhibits COX enzymes. However, the body can convert about 60% of the inactive R-form into the active S-form. This is why most ibuprofen products contain a racemic (50/50) mixture - the body can utilize both forms effectively. Some newer formulations contain only the active S-ibuprofen to potentially reduce dosage requirements.

Answer: B) Non-selective inhibition of both COX-1 and COX-2 enzymes Explanation: Ibuprofen works by reversibly inhibiting both cyclooxygenase (COX) enzymes, COX-1 and COX-2, which are responsible for prostaglandin synthesis. This dual inhibition provides its pain-relieving, anti-inflammatory, and fever-reducing effects, but also explains its potential side effects like stomach irritation (from COX-1 inhibition) and cardiovascular risks (from COX-2 inhibition). Unlike selective COX-2 inhibitors, ibuprofen's effect on COX-1 also gives it mild antiplatelet properties at standard doses.