(±)-Propranolol-d₇is intended for use as an internal standard for the quantification of propranolol by GC- or LC-MS. (±)-Propranolol is a β-adrenergic receptor (β-AR) antagonist (K_ds = 6.91, 0.832, and 117.49 nM for human β₁-, β₂-, and β₃-ARs, respectively).¹It reduces mean blood pressure, resting heart rate, and contractility and increases AV conduction time in dogs.²(±)-Propranolol restores normal sinus rhythm in dogs with ouabain-induced arrhythmias (ED₅₀= 3.8 mg/kg).³It also acts as a non-specific serotonin receptor antagonist, reducing tranylcypromine/L-tryptophan-induced hyperactivity in rats.⁴Formulations containing (±)-propranolol have been used for the treatment of hypertension, angina pectoris, and cardiac ischemia.

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