Sildenafil, also known as Viagra, enhances blood flow and cerebrovascular function in individuals with cerebral small vessel disease, according to OxHARP trial results.
Published in Circulation Research, the study assessed sildenafil's potential benefits on cerebrovascular function in patients with cerebral small vessel disease. The double-blind, randomized, placebo-controlled, 3-way crossover trial included 75 participants (median age 70 years; 79% male) with mild to moderate white matter hyperintensities (WMH).
The primary endpoint evaluated the effects of 3 weeks of sildenafil (50 mg,3 times daily) compared to placebo on middle cerebral artery pulsatility. Results indicated no significant change in cerebral pulsatility with sildenafil compared to placebo (0.02, −0.01 to 0.05; P = 0.18) or cilostazol (−0.01, −0.04 to 0.02; P = 0.36). However, sildenafil increased peak systolic velocity (6.3 cm/s, 3.5–9.07; P < 0.001) and end-diastolic velocity (1.98 cm/s, 0.66–3.29; P = 0.004).
Secondary outcomes showed that sildenafil improved cerebrovascular reactivity and perfusion in WMH and normal-appearing white matter and reduced cerebrovascular resistance (P = 4.9 × 10−8). Adverse effects included increased headaches with both drugs (P = 1.1 × 10−4) and more moderate to severe diarrhea with cilostazol (P = 0.013).
Researchers noted that sildenafil's potential to improve brain blood flow and prevent vascular dementia warrants further large-scale trials.
The study was funded by the Wellcome Trust and supported by the National Institute for Health and Care Research.