Which serious adverse reaction from progesterone therapy requires immediate medical attention?

• A. Breakthrough bleeding
• B. Nipple discharge
• C. Low blood pressure
• D. Calf pain and swelling

Answer: (D)

The serious adverse reaction from progesterone therapy that requires immediate medical attention is calf pain and swelling. This symptom can be indicative of deep vein thrombosis (DVT), a condition in which a blood clot forms in a deep vein, typically in the legs. DVT can potentially lead to serious complications, including a pulmonary embolism, where the clot dislodges and travels to the lungs, which can be life-threatening.

Prompt identification and treatment of DVT are crucial to prevent these severe outcomes. Symptoms like calf pain and swelling should never be ignored, particularly in patients who are on hormone therapy, as they may be at an increased risk for thromboembolic events due to the effects of progesterone on blood coagulation.

In contrast, breakthrough bleeding and nipple discharge are generally not considered urgent medical issues. While they can be concerning and may need evaluation, they do not immediately threaten the patient's life or require urgent intervention. Low blood pressure might indicate a serious issue, but it depends on the context and underlying causes, making it less specific as an immediate concern compared to the clear risk of DVT associated with calf pain and swelling.