Nafetolol (K 5407), specifically effective on cardiac (β1)-adrenoceptors, is an orally active β blocking agent, with a t1/2 of ~ 2 h in dogs.
References:
[1]. G Goldaniga, et al. Pharmacokinetics and metabolism of a new beta-adrenergic blocking agent, the 1, ter-butyl-amino-3-(1,2,3,4-tetradro-1,4-ethano-8-droxy-5-naphthoxy)-2-propanol (K 5407). Eur J Drug Metab Pharmacokinet. 1980;5(1):9-20.