What is a common gastrointestinal side effect of phentermine?

Phentermine is a sympathomimetic amine commonly used as an appetite suppressant in weight management. One of its prevalent gastrointestinal side effects is constipation. This occurs because phentermine can stimulate the sympathetic nervous system, which may slow down gastrointestinal motility. As a result, patients may experience difficulties in regular bowel movements, leading to constipation.

While other gastrointestinal side effects, such as nausea and heartburn, can also occur with phentermine, constipation is particularly noted as a common and significant issue among patients taking this medication. Understanding this side effect is essential for healthcare providers to manage symptoms effectively and provide appropriate educational counseling to patients about what they might experience while on phentermine.