Possible Interaction: Practolol and 1-(P-Hydroxybenzyl)-6,7-Dihydroxy-1,2,3,4-Tetrahydroisoquinoline

“ Practolol (1 nM), a selective beta 1-adrenergic antagonist, but not butoxamine (… microM), a beta 2-adrenergic antagonist, blocked the potentiation by higenamine (5 nM) of the aconitine-induced positive chronotropic effect and, at high concentrations (… and 300 nM) also shifted the aconitine concentration-response curves to the right.”

“The positive chronotropic effect of higenamine was antagonized by propranolol (30-300 nM) and practolol (10 nM-3 microM), but not by butoxamine (1 microM), indicating that it was a beta 1-adrenoceptor-mediated action.”