**Question:** Which of the following statements is NOT TRUE about NSAIDs?

A. Non-steroidal anti-inflammatory drugs (NSAIDs) are used to reduce inflammation and pain.
B. NSAIDs inhibit the enzyme cyclooxygenase (COX), which is responsible for prostaglandin synthesis.
C. NSAIDs can cause gastrointestinal bleeding due to inhibition of COX enzymes in the stomach lining.
D. NSAIDs are contraindicated in patients with a history of severe asthma.

**Correct Answer: D. NSAIDs are contraindicated in patients with a history of severe asthma.**

**Core Concept:** NSAIDs are a class of drugs primarily used to relieve pain, reduce inflammation, and lower body temperature. They work by inhibiting the enzyme cyclooxygenase (COX), which is involved in the synthesis of prostaglandins. Prostaglandins are lipid compounds produced by the conversion of arachidonic acid through the action of COX enzymes (COX-1 and COX-2) in various tissues, including the stomach mucosa and airways.

**Why the Correct Answer is Right:** In asthmatic patients, especially those with a history of severe asthma, the use of NSAIDs can be harmful due to their ability to inhibit COX enzymes. Inhibition of COX-1 and COX-2 enzymes results in a decrease in prostaglandin synthesis, including those that protect the stomach lining (prostaglandin I2 or PGI2), leading to increased risk of gastrointestinal bleeding and ulcers.

**Why Each Wrong Option is Incorrect:**

**A. NSAIDs are used to reduce inflammation and pain:** This statement is true, but option D focuses on a contraindication related to severe asthma.

**B. NSAIDs inhibit the enzyme cyclooxygenase (COX), which is responsible for prostaglandin synthesis:** This statement is true, but option D focuses on a contraindication related to severe asthma.

**C. NSAIDs can cause gastrointestinal bleeding due to inhibition of COX enzymes in the stomach lining:** This statement is true, but option D focuses on a contraindication related to severe asthma.

**D. NSAIDs are contraindicated in patients with a history of severe asthma:** This statement is the correct answer, as it highlights a specific contraindication for using NSAIDs in patients with a history of severe asthma. NSAIDs should be avoided in this patient population due to the risk of severe exacerbation of asthma symptoms and potentially life-threatening complications.

**Clinical Pearl:** In patients with a history of severe asthma, alternative analgesics and anti-inflammatory agents should be considered, such as paracetamol (acetaminophen) or selective COX-2 inhibitors (e.g., celecoxib), which have a lower risk of gastrointestinal complications compared to non-selective NSAIDs. These alternative medications can be used in these patients to manage pain and inflammation without increasing the risk of asthma exacerbation.