Study design: Prospective, open-label, comparative study, to assess the effects of sildenafil on blood pressure in a population of patients with spinal cord injury (SCI).
Objectives: To determine the effect of sildenafil on blood pressure in patients with erectile dysfunction secondary to SCI by comparing changes in blood pressure in SCI patients with a neurologic level below T5 versus higher levels. To establish a relationship between the potential hypotensive effect and protective muscle spasm against blood pressure reduction. To assess the effects of age, complexity and duration of SCI on changes in blood pressure. To record any adverse effects occurring during the study.
Setting: Spinal Cord Injury Unit, Insular University Hospital of Gran Canaria, Canary Islands, Spain.
Subjects: In total, 22 male SCI patients aged 18 years or older with a history of SCI greater than 3 months in duration.
Methods: Patients with erectile dysfunction secondary to SCI were included in the study, without excluding patients with a neurologic level above 75 or asymptomatic low blood pressure. Patients with specific contraindications for use of the drug were excluded. A personal history was obtained, and the level of injury (ASIA/IMSOP scales of international standards), impairment grade (ASIA impairment scale), spasticity grade (modified Ashworth scale) and baseline sitting and supine blood pressure values were determined. A single dose of 50 mg of sildenafil was administered, and patients remained sitting at 45 degrees . Blood pressure was monitored every 10 min for 4 h and whenever the patient reported symptoms. Any relevant signs and symptoms manifested during the study period were also recorded. Analysis of the changes in blood pressure values was performed using a paired t-test in each group of patients according to neurologic level and spasticity grade.
Results: A decrease in blood pressure was observed in all patients, although patients with a level of injury at T5 or above and those with a complete SCI showed a less intense decrease (P<0.05). The spasticity grade of the patients was protective against the fall in blood pressure, as it was less significant in patients with grade 3 (P>0.1) than in those with grade 0. Adverse effects were few and transient. None were related to hypotension.
Conclusion: Sildenafil caused a decrease in blood pressure in SCI patients with a neurologic level of injury above T5 and complete injuries (grade A), but did not have clinical implications in the patients studied. A higher spasticity grade tends to protect the patient from the fall in blood pressure. Age and duration of injury do not appear to influence this decrease.
Spinal Cord (2006) 44, 301-308. doi:10.1038/sj.sc.3101846; published online 11 October 2005.