Purpose: Droxidopa has been approved for the treatment of neurogenic orthostatic hypotension (NOH) under the US Food and Drug Administration accelerated approval program, which warrants confirmatory evidence on long-term efficacy of droxidopa. Hereby, we synthesize evidence from published randomized controlled trials (RCTs) about the safety and efficacy of droxidopa for patients with neurogenic orthostatic hypotension.
Methods: A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central was conducted using relevant keywords. Records were screened for eligible studies and data were extracted and synthesized using Review Manager version 5.3 for Windows. Subgroup analysis and sensitivity analysis were conducted to investigate long-term durability of droxidopa against placebo.
Results: Four RCTs with a total of 485 patients (droxidopa, n = 246; placebo, n = 239) were eligible for the final analysis. The mean difference (MD) of change in the main outcomes from baseline to endpoint favored droxidopa than placebo [Orthostatic Hypotension Questionnaire (OHQ) MD -0.61, P = 0.004; dizziness/lightheadedness score MD -0.83, P = 0.008; and standing systolic blood pressure (SBP) MD 4.09, P = 0.03]. The efficacy of droxidopa decreased gradually after 2 weeks, and its statistical significance was lost after 8 weeks (OHQ score MD -0.18, P = 0.61; dizziness/lightheadedness score MD -0.71, P = 0.11; and standing SBP MD 2.96, P = 0.29). None of the adverse events were significantly higher in the case of droxidopa compared to placebo.
Conclusion: Droxidopa is a safe and effective drug for the short-term management of NOH symptoms. However, current evidence is insufficient to confirm the efficacy of droxidopa for long-term use. Therefore, further studies with increased sample size are needed.
Keywords: Dizziness; Droxidopa; Orthostatic hypotension; Parkinson’s disease; Pure autonomic failure.