Combination therapy of midodrine and droxidopa for refractory hypotension in heart failure with preserved ejection fraction per a pharmacist's proposal: a case report.

Background: Patients with chronic heart failure (CHF) are often treated using many diuretics for symptom relief; however, diuretic use may have to continue despite hypotension development in these patients. Here, we present a case of heart failure with preserved ejection fraction (HFpEF), which is defined as ejection fraction ≥50% in CHF, and refractory hypotension, which was treated with midodrine and droxidopa to normalize blood pressure.
Case Presentation: The patient was a 62-year-old man with a history of HFpEF due to mitral regurgitation and complaints of dyspnea on exertion. He had been prescribed multiple medications at an outpatient clinic for CHF management, including azosemide 60 mg/day, bisoprolol 2.5 mg/day, enalapril 2.5 mg/day, spironolactone 50 mg/day, and tolvaptan 15 mg/day. The systolic blood pressure (SBP) of the patient remained at 70-80 mmHg because the use of the diuretic could not be reduced or discontinued owing to edema and weight gain. He was hospitalized for the exacerbation of CHF. Although midodrine 8 mg/day was administered to improve hypotension, the SBP of the patient increased only up to 90 mmHg. On the 35th day after hospitalization, the urine volume decreased significantly (< 100 mL/day) due to hypotension. When droxidopa 200 mg/day replaced intravenous noradrenaline on the 47th day, the SBP remained at 100-120 mmHg and the urine volume increased.
Conclusions: Oral combination treatment with midodrine and droxidopa might contribute to the maintenance of blood pressure and diuretic activity in HFpEF patients with refractory hypotension. However, further long-term studies evaluating the safety and efficacy of this combination therapy for patients with HFpEF are needed.