Twenty-four hour blood pressure profiles in hypertensive patients following various formulations and dosage regimens of felodipine.

The blood pressure lowering capacity of felodipine administered either as extended release tablets once or twice daily or as plain tablets twice daily has been compared in a double-blind, three-way cross-over study in 16 hypertensive patients. All the patients were on long-term treatment with 10 or 20 mg felodipine daily and other antihypertensive therapy (mainly beta-blockers) was allowed if it was kept unchanged. Non-invasive blood pressure and heart rate recordings were obtained throughout 24 hour periods using an Accutracker ambulatory system. The 24 h mean systolic and diastolic blood pressures after extended release tablets o.m. did not differ significantly from those after extended release tablets b.d. or plain tablets b.d. There was a tendency for the extended release tablets given o.m. to reduce blood pressure somewhat more in the morning, and for the extended release tablets b.d. to reduce blood pressure more during the night than the other treatments. Mean 24 h heart rate after all treatments was comparable. Manual recordings confirmed these results. Blood pressure was well-controlled throughout the 24 h period by all three treatments. The extended release tablets tended to give less extreme plasma concentrations of felodipine. This may be of value for patients with adverse vasodilator effects. For a majority of hypertensive patients the adequacy of blood pressure control and the simplicity of once daily dosing will favour the extended release tablet given once daily.