Which of the following is an adverse effect of heparin?

Heparin is an anticoagulant medication commonly used to prevent and treat blood clots. One of the significant adverse effects associated with heparin therapy is excessive bleeding, which can manifest in various ways, including bleeding gums. This occurs because heparin works by inhibiting the blood coagulation process, resulting in a decreased ability for blood to clot, leading to potential complications like hemorrhaging.

The other options do not directly relate to the known adverse effects of heparin. Increased appetite and weight gain are not typical reactions to heparin; in fact, weight gain could occur due to fluid retention or other factors unrelated to this medication. Frequent headaches are also not an established side effect of heparin therapy. Therefore, the manifestation of excessive bleeding gums serves as a clear indicator of heparin's impact on the body, aligning with the pharmacological effects of anticoagulation.