Haemodynamic effects of fludrocortisone and midodrine in patients with symptoms due to hypotension

The study aimed to assess the haemodynamic effects of fludrocortisone and midodrine, alone or combined, in patients with recurrent syncope and/or symptoms due to hypotension and ≥ 1 daytime systolic blood pressure (SBP) drop < 90 mmHg or ≥ 2 daytime SBP drops < 100 mmHg recorded by 24-h ambulatory blood pressure monitoring (ABPM1).

A total of 53 patients (mean age, 40.9 ± 18.5 years, 37 female) were treated with fludrocortisone (0.05-0.2 mg per day) and/or midodrine (2.5-10 mg two or three times per day). A second ABPM (ABPM2) was performed within 6 months and the results of ABPM1 AND ABPM2 were compared to assess the effects of BP-rising drugs.

In 32 patients assigned to fludrocortisone, 24-h SBP increased from 107.1 ± 9.9 mmHg to 116.3 ± 14.9 (p = 0.0001), the number of daily SBP drops < 90 mmHg decreased by 73% (p = 0.0001) and that of drops < 100 mmHg decreased by 41% (p = 0.0005). In 14 patients assigned to midodrine, 24-h SBP increased from 112.7 ± 7.4 mmHg to 115.0 ± 9.1 (p = 0.12), the number of daily SBP drops < 90 mmHg decreased by 52% (p = 0.04) and that of drops < 100 mmHg decreased by 34% (p = 0.007). In the seven patients taking both fludrocortisone and midodrine, 24-h SBP increased from 110.1 ± 11.5 mmHg to 114.0 ± 12.4 (p = 0.002), the number of daily SBP drops < 90 mmHg decreased by 69% (p = 0.22) and that of drops < 100 mmHg decreased by 44% (p = 0.04).

Both fludrocortisone and midodrine effectively increased 24-h SBP and reduced SBP drops on ABPM but fludrocortisone seemed to be more effective than midodrine. Further randomised studies are needed to confirm these observations.