Magnesium trisilicate in the presence of renal insufficiency may cause central nervous system depression and other symptoms of hypermagnesemia. This product should not be administered to patients receiving a prescription antibiotic containing any form of tetracycline. Its interference in the absorption of other drugs should be considered. Sodium citrate and tartrate inhibits the neutralization of gastric acid by dried aluminium hydroxide gel. The effect of aluminium hydroxide on phosphate should always be carefully considered.