Objective: To compare the safeties and efficacies of IV fenoldopam (FNP) vs sodium nitroprusside (NTP) in severe acute hypertension.
Methods: A prospective, randomized, open-label, multicenter international trial, at 24 academic medical centers, was conducted. The participants were adult patients (21-80 years of age) who had supine diastolic blood pressures (DBPs) > or = 120 mm Hg, were capable of written informed consent, and did not have selected exclusion criteria. The subjects were randomized to either FNP or NTP therapy; DBP was titrated to 95-110 mm Hg, or a maximum reduction of 40 mm Hg for very high pressures. Infusions were maintained for at least six hours, then the patients were weaned off the IV therapy and oral medication was started. Measurements included BP, heart rate, and duration of study drug infusion and frequency of side effects or complications.
Results: A total of 183 patients (90 FNP, 93 NTP) were enrolled. Fifteen patients from each arm were excluded from efficacy analysis due to protocol violation. There was no significant difference in baseline characteristics. The two antihypertensive agents were equivalent in controlling and maintaining DBP. Systolic blood pressure (SBP) was reduced to a slightly greater degree for the NTP-treated patients during the initial (0.5-1-hr) study period, and both SBP and DBP were reduced more for the FNP-treated patients in the subset receiving infusions during the 12-24-hour period. The adverse effect profiles of the drugs were similar, as were the times to achieve target pressure, with no clinically relevant difference.
Conclusions: For patients who had acute severe hypertension, FNP and NTP were equivalent in terms of efficacy and acute adverse events. Because of a unique mechanism of action, FNP may have advantages in selected subsets of patients. Further studies may be indicated in patient populations with pure "hypertensive emergencies."