<p>Catecholamine‐depleting drugs (e.g. Reserpine, Monoamine Oxidase (MAO) inhibitors) may have an additive effect when given with beta‐blocking agents. Drugs that inhibit CYP2D6 such as quinidine, fluoxetine, paroxetine and propafenone are likely to increase Metoprolol concentration. These increases in plasma concentration would decrease the cardioselectivity of Metoprolol. Concomitant use of digitalis glycosides and beta‐blockers can increase the risk of bradycardia. Beta‐blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine.</p>