Pharmacokinetic studies of practolol, a beta adrenergic antagonist, in man

The disposition of practolol after oral and intravenous administration was studied in hypertensive patients. The plasma half‐life was 13.2 hours. After intravenous administration practolol was recovered quantitively in the urine. Its volume of distribution was larger than that of body water, 1.6 L. per kilogram, and its clearance from this volume, 135 ml. per minute, was equal to renal clearance of the drug; both were slightly higher than the creatinine clearance. Despite its weakly basic character, this aromatic alkylamine was not affected by changes in urinary pH from 5.4 to 8.0. These studies indicate that practolol is slowly removed from the body and that it is excreted entirely by the kidneys.