Which of the following is the least acidic NSAID?
**Core Concept**
The question is testing the understanding of the chemical properties of nonsteroidal anti-inflammatory drugs (NSAIDs), specifically their acidity. NSAIDs are a class of medications used to reduce inflammation and pain, and their acidity is an important factor in determining their pharmacokinetics and potential side effects.
**Why the Correct Answer is Right**
The acidity of an NSAID is related to its pKa value, which is a measure of the strength of an acid. A lower pKa value indicates a stronger acid. Among the NSAIDs, ibuprofen has a relatively low pKa value of 5.2, which makes it less acidic compared to other NSAIDs. This property is important because it affects the drug's absorption, distribution, and metabolism.
**Why Each Wrong Option is Incorrect**
**Option A:** Naproxen has a pKa value of 4.2, making it a stronger acid than ibuprofen. Therefore, it is not the least acidic NSAID.
**Option B:** Ketoprofen has a pKa value of 4.9, which is higher than ibuprofen's but still lower than some other NSAIDs. This makes it less acidic than ibuprofen, but not the least acidic.
**Option C:** Diclofenac has a pKa value of 4.0, making it a stronger acid than ibuprofen. Therefore, it is not the least acidic NSAID.
**Clinical Pearl / High-Yield Fact**
When choosing an NSAID, clinicians should consider the patient's individual factors, such as gastrointestinal risk, renal function, and potential interactions with other medications. Understanding the chemical properties of NSAIDs, including their acidity, can help inform these decisions.
**Correct Answer: C. Diclofenac.**