ABSTRACT
Ten patients with essential hypertension were hospitalized and treated with placebo, followed by their usual dose of propranolol. Systolic and diastolic blood pressure decreased significantly after the first dose of propranolol, and by the third day of propranolol treatment reached 84% to 92% of the maximum decrease achieved during the 6 days of treatment. Mean maximum falls in blood pressure were 13/12 mm Hg supine and 12/13 mm Hg standing. This development of the decrease in heart rate and blood pressure over 48 hours occurred in parallel with cumulation of propranolol to steady state in plasma. The decrease in diastolic, but not systolic, arterial pressure was directly related to pretreatment blood pressure, but not significantly related to pretreatment plasma renin activity (PRA) or change in PRA. Thus, single doses of propranolol lowered blood pressure in patients with essential hypertension, and with continued therapy, near maximum antihypertensive effects were achieved within 48 hours.
Subject(s)
Hypertension/drug therapy , Propranolol/therapeutic use , Adult , Blood Pressure/drug effects , Dose-Response Relationship, Drug , Female , Heart Rate/drug effects , Humans , Male , Middle Aged , Posture , Propranolol/blood , Renin/blood , Time FactorsABSTRACT
1 Single oral doses of lofexidine, 0.1, 0.3, and 0.6 mg produced dose related decreases in supine and standing arterial pressure and heart rate in nineteen patients with essential hypertension. 2 A mean oral antihypertensive threshold dose of less than 0.1 mg was estimated. 3 Lofexidine decreased mean urinary noradrenaline excretion 28% and caused significant retention of sodium and water. 4 The most prominent side effects were sedation and orthostatic dizziness. 5 Lofexidine is pharmacologically similar to, but apparently less potent than clonidine as an antihypertensive agent.
