Objective: To perform a systematic review and meta-analysis of clinical trials evaluating the efficacy and safety of midodrine in orthostatic hypotension (OH).
Methods: We searched major databases and related conference proceedings through June 30, 2012. Two reviewers independently selected studies and extracted data. Random-effects meta-analysis was used to pool the outcome measures across studies.
Results: Seven trials were included in the efficacy analysis (enrolling 325 patients, mean age 53 years) and two additional trials were included in the safety analysis. Compared to placebo, the mean change in systolic blood pressure was 4.9 mmHg (p = 0.65) and the mean change in mean arterial pressure from supine to standing was -1.7 mmHg (p = 0.45). The change in standing systolic blood pressure before and after giving midodrine was 21.5 mmHg (p < 0.001). A significant improvement was seen in patients' and investigators' global assessment symptoms scale (a mean difference of 0.70 [95 % CI 0.30-1.09; p < 0.001] and 0.80 [95 % CI 0.76-0.85; p < 0.001], respectively). There was a significant increase in risk of piloerection, scalp pruritis, urinary hesitancy/retention, supine hypertension and scalp paresthesia after giving midodrine. The quality of evidence was limited by imprecision, heterogeneity and increased risk of bias.
Conclusion: There is insufficient and low quality evidence to support the use of midodrine for OH.