Safety, tolerability and pharmacokinetics of an intravenous bolus of sildenafil in patients with pulmonary arterial hypertension.

Aims: To assess pharmacokinetics and pharmacodynamics of a 10 mg intravenous sildenafil bolus in pulmonary arterial hypertension (PAH) patients stabilized on 20 mg sildenafil orally three times daily.

Methods: Pharmacokinetic parameters were calculated using noncompartmental analysis.

Results: After an acute increase, plasma concentrations stabilized within the range reported previously for a 20 mg oral tablet. At 0.5 h, mean ± SD changes from baseline were -8.4 ± 11.7 mmHg (systolic pressure), -2.6 ± 7.3 mmHg (diastolic pressure) and -3.5 ± 10.4 beats min(-1) (heart rate). There was no symptomatic hypotension.

Conclusions: Although further research is warranted, a 10 mg sildenafil intravenous bolus appears to provide similar exposure, tolerability and safety to the 20 mg tablet.