Absorption of the β-Adrenergic-Blocking Agent, Nadolol, by Mice, Rats, Hamsters, Rabbits, Dogs, Monkeys, and Man: An Unusual Species Difference

Abstract

1. Dogs absorbed [¹⁴C]nadolol almost completely (88-104%) after oral administration of 10-75 mg/kg. In contrast, mice, rats, hamsters, and rabbits, given oral doses of 20 mg/kg, absorbed, at most, 25%. After administration of oral doses of 2-75 mg/kg, monkeys absorbed no more than an average of 30%. Six monkeys given oral doses of 10 mg/kg absorbed 12-44%.

2. In rats, [¹⁴C]nadolol was orally absorbed to an average of 13·7-17·5%, whether given in suspension or in solution, indicating that absorption was not limited by rate of dissolution nor by solubility.

3. Mildly hypertensive humans given single doses of [¹⁴C]nadolol (2 or 80 mg, orally) and normal subjects given single doses (10 mg, orally) absorbed an average of 20·4-33·3%.