Metaproterenol also has anti-inflammatory activity. Metaproterenol is a direct-acting sympathomimetic and a β2-adrenergic receptor (β2AR) agonist (IC50: 68 nM).
Selective, high affinity, non-competitive α1A adrenoceptor antagonist (Ki = 0.35 nM). Exhibits no significant activity against a range of other GPCRs, including α2A, β1 and β2 adrenoceptors. Antagonizes effects of phenylephrine on isolated rabbit prostate