Two individuals taking sotalol developed a side effect of the drug (a heart arrhythmia known as torsades de pointes) which was effectively treated with intravenous magnesium.^{1 , 2} Additional research is needed to determine whether people taking sotalol might be able to prevent this side effect by taking supplemental magnesium.

One controlled study showed that taking sotalol with a calcium gluconate solution dramatically reduces the absorption of the drug.³ Consequently, people who take a calcium supplement should take sotalol an hour before or two hours after the calcium.

As pleurisy root and other plants in the Aesclepius genus contain cardiac glycosides, it is best to avoid use of pleurisy root with heart medications such as beta-blockers.⁴

People with prolonged diarrhea and vomiting, as well as those taking potassium-depleting diuretics, might develop low blood potassium levels. Individuals with low blood potassium levels who take sotalol have an increased risk of developing a serious heart arrhythmia and fainting. Therefore, people taking sotalol should have their blood potassium levels checked regularly and may need to supplement with potassium, especially when taking potassium-depleting diuretics.

Some beta-adrenergic blockers (called “nonselective” beta blockers) decrease the uptake of potassium from the blood into the cells,⁵ leading to excess potassium in the blood, a potentially dangerous condition known as hyperkalemia.⁶ People taking beta-blockers should therefore avoid taking potassium supplements, or eating large quantities of fruit (e.g., bananas), unless directed to do so by their doctor.