Endocrine Abstracts

Introduction: Primary Pulmonary Hypertension (PPH) is a condition defined by atypically high blood pressure in the vessels in the lungs and heart. Due to the high blood pressure in the pulmonary system, the arteries in the lungs shrink and reduce oxygen flow throughout the body. It is characterized by shortness of breath and chest pain, and can often be linked with heart disease, lung disease, or connective tissue disease. Patients with PPH are typically treated with Sildenafil or Tadalafil which is a phosphodiesterase inhibitor which relaxes the vessels to improve blood flow.

Case Presentation: A 55-year-old African American female with PPH presents with slurred speech, dizziness, and hypoglycemia. The patient was talking with someone on the phone and was unintelligible and EMS was called. The patient does not smoke or drink, works out with a trainer, and describes herself as a healthy eater. The patient was diagnosed with PPH in December 2022 and started treatment immediately after. She was then treated with a variety of medications including Sildenafil, Macitentan, Spironolactone, and Digoxin. The patient admits that she frequently forgets to take her mid day doses of medications Monday through Friday for the past 3 months which likely contributes to her worsening symptoms. The patient with PPH and HF was taken to the ER to rule out a stroke and was found to have hypoglycemia on arrival with a sugar of 38 mg/dl. She was treated with a dextrose solution of 25 g to improve her sugars and symptoms resolved. Her sugar dropped again in the ER and she was admitted for evaluation of an insulinoma. The workup was negative and the care team concluded that the hypoglycemia was not due to an issue with the patient’s pancreas. Nutrition counseling was given including the addition of bedtime snacks of protein, fat, and carbohydrates and the avoidance of simple sugars. Her hypoglycemia improved but did not resolve. Then, Sildenafil was suspected of causing the low sugar. The medication was changed to 20 mg Tadalafil and the hypoglycemia resolved.

Discussion: There are case reports of hypoglycemia with Sildenafil in 2% of patients post trials. After being taken off the Sildenafil, the patient had improved sugars and no further hypoglycemia.

Conclusion: This case illustrates the possibility for patients to develop extreme hypoglycemia when on Sildenafil. Physicians should have a high index of suspicion for patients who have incidents of hypoglycemia on treatment.