Medroxalol (RMI81968) is an orally active adrenergic receptor antagonist that blocks both α- and β-adrenergic receptors, producing antihypertensive and vasodilating effects [1].

Medroxalol, at concentrations ranging from 0.1-10 μM over a 20-minute incubation period, exhibits antagonistic activity against both α- and β-adrenergic receptors in isolated rabbit aortic strips, as demonstrated by the Cell Viability Assay. Specifically, the assay results reveal pA2 values of 6.09 for α-adrenergic receptors and 7.73 for β-adrenergic receptors, indicating its efficacy in blocking these receptor types [1].

Medroxalol treatment, administered via oral gavage at dosages of 12.5 to 50 mg/kg once daily for 12 days, demonstrates antihypertensive activity by inducing a dose-dependent decrease in blood pressure in male spontaneously hypertensive rats (SHR) [1].