Final answer:
One adverse effect of warfarin is increased menstrual flow. The nurse should notify the provider if the patient experiences this side effect.
Step-by-step explanation:
Warfarin is a medication used to prevent blood clotting, especially in patients with conditions like atrial fibrillation. One of the adverse effects of warfarin is increased menstrual flow, which means that the nurse should notify the provider if the patient experiences this side effect. Clay-colored stools, overgrowth of gingival tissue, and dry, non-productive cough are not typically associated with warfarin use.