(-) -Dihydroalprenolol (L-Dihydroalprenolol) is a β-adrenergic antagonist that inhibits the activity of β-adrenergic receptors. (-) -Dihydroalprenolol can cause desensitization of approximately 60% of β-adrenergic receptor binding sites. (-) -Dihydroalprenolol has also been shown to reduce the binding capacity of specific β-adrenergic ligands. (-) -Dihydroalprenolol may affect the ability to stimulate membrane-bound adenylate acylase[1].