Administer tetracycline and fluoroquinolone antibiotics, iron, digoxin, chlorpromazine, and penicillamine at least 2 hours before and not less than 6 hours after administration of sodium sulfate, potassium sulfate, and magnesium sulfate oral solution to avoid chelation with magnesium.
Source: FDA drug label - sodium sulfate anhydrous, potassium sulfate, and magnesium sulfate