If you take these medications to control blood sugar, your doctor may need to adjust your dose. Digoxin (Lanoxin): Low blood levels of magnesium can increase negative effects from digoxin, including heart palpitations and nausea. In addition, digoxin can cause more magnesium to be lost in the urine. A doctor will monitor magnesium levels in people taking digoxin to see whether they need a magnesium supplement.