(+)‐Propranolol clearance, an estimation of hepatic blood flow in man.

1 Hepatic blood flow was determined before and during (+)‐ and (+/‐)‐ propranolol plasma concentration plateaus in 19 patients with suspected renal hypertension and normal liver function. 2 Hepatic blood flow significantly decreased (P less than 0.001) during (+/‐)‐propranolol administration and remained unchanged during (+)‐propranolol administration. 3 Hepatic extraction ratio was 74 +/− 1% (+/‐)‐ propranolol and 79 +/− 2% for (+)‐propranolol. 4 Total propranolol clearances were determined during the steady‐state achieved by a constant infusion. A highly significant positive relationship was observed (r = +0.86; P less than 0.01) between hepatic blood flow and (+)‐propranolol clearance. The slope of the curve was 1.05 +/− 0.27. 5 The result implies that the total clearance of (+)‐propranolol constitutes an accurate estimation of basal hepatic blood flow in subjects with normal liver function.