Article date: July 1982
By: C. Bahr, J. Hermansson, K. Tawara, in Volume 14, Issue 1, pages 79-82
1 We have given fifteen healthy volunteers single doses of racemic (+/‐)‐propranolol orally (40 mg) and intravenously (5‐10 mg) to find out how large the variation was of the ratio between (−)− and (+)‐ propranolol plasma levels in relation to that of total levels of propranolol and 4‐hydroxypropranolol. 2 Total propranolol (+/‐)‐levels 2 h after a 40 mg oral dose of (+/‐)‐propranolol varied from 21 to 580 nmol/l and those of 4‐hydroxypropranolol from 0 to 33 nmol/l. Their levels did not correlate. The ratio between (−)− and (+)‐propranolol levels varied from 0.99 to 2.04. The plasma half‐lives of the two isomers were usually similar. 3 We conclude that in most single doses studies on relationships between plasma concentrations and effects (beta‐adrenoceptor blockade) it is not necessary to quantitate (+)‐ and (−)−propranolol levels separately since total (+/‐) plasma propranolol levels varied much more than the ratio between (−)− and (+)‐propranolol.
DOI: 10.1111/j.1365-2125.1982.tb04937.x
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