Which side effect is less likely associated with acetaminophen compared to naproxen?

Acetaminophen is less likely to cause gastrointestinal (GI) disturbances compared to naproxen due to its pharmacological properties. Naproxen, being a nonsteroidal anti-inflammatory drug (NSAID), can irritate the gastric mucosa and is associated with a variety of GI side effects, such as nausea, vomiting, and ulcer formation. This is primarily due to the inhibition of cyclooxygenase (COX) enzymes that produce prostaglandins, which have a protective effect on the gastrointestinal lining.

In contrast, acetaminophen primarily acts centrally in the brain and does not possess anti-inflammatory properties that affect the GI tract. Therefore, patients taking acetaminophen typically experience fewer GI disturbances. This makes acetaminophen a preferred choice for individuals who may be sensitive to the GI side effects associated with NSAIDs like naproxen.

While naproxen can be implicated in bleeding and heartburn due to its gastrointestinal effects, acetaminophen does not share these characteristics. Headaches can occur with varying frequency regardless of the medication, but the point of comparison is specifically around the likelihood of GI disturbances. Thus, citing GI disturbances as the correct answer highlights acetaminophen's comparatively benign profile regarding gastrointestinal side effects.