The pharmacodynamics and pharmacokinetics of conventional and long-acting propranolol in patients with moderate hypertension.

1 The effects on heart rate and blood pressure after single and multiple dosing (1 month) of a long acting formulation of propranolol 160 mg daily, and conventional propranolol, 80 mg twice daily, or 160 mg daily were compared in 11 moderately hypertensive subjects previously shown to respond to propranolol. 2 After acute dosing all three treatments produced significant reduction in blood pressure. After multiple dosing all three treatments maintained significant reductions in lying, standing and exercise heart rate and blood pressure throughout the 24 h. At 24 h, after multiple dosing, the fall in resting and standing systolic BP was significantly greater with LA propranolol than with conventional propranolol 80 mg twice daily or conventional propranolol 160 mg once daily (P at least less than 0.05). 3 The plasma propranolol concentration time curve after LA propranolol showed slowed absorption, and the area under the curve was significantly lower than after conventional propranolol (acute dosing; LA propranolol 160 mg 560 mg ml-1 h, conventional propranolol 80 mg twice daily 1135 mg ml-1 h, conventional propranolol 160 mg daily 1414 mg ml-1 h).