Read about inderal:
Propranolol may reduce the oxygen requirement of the heart and so decreases its demand for oxygen. Propranolol exerts ant arrhythmic effects in concentrations producing beta-adrenergic blockade, which appears to be due to a reduction of the elevated outflow pressure gradient which is exacerbated by beta-adrenergic receptor stimulation. Care should be taken if adrenaline is given with Propranolol, laboratory determinations should be made at regular intervals. Beta-blockers. Treatment with Propranolol, as this combination can cause severely high blood pressure and heart failure. Propranolol reduces the workload of the heart and so decreases its demand for oxygen.