– (±)-4-hydroxy Propranolol β-D-glucuronide is a metabolite of (±)-4-hydroxy propranolol , which is a metabolite of propranolol. The apparent half-life of (±)-4-hydroxy propranolol β-D-glucuronide is similar to propranolol and 4-hydroxy propranolol. Propranolol is a β-adrenergic antagonist, and the active enantiomer, (S)-(-)-propranolol , has log Kd values of -8.16, -9.08, and -6.93 for β1, β2, and β3, respectively.