The pairs whose both species are used in anti acid medicinal preparation is

sodium hydrogen carbonate (or) a mixture of Al(OH)3 & Mg(OH)2 [NaHCO3] are used for the treatment for acidityNote :Over production of acid in the stomach causes irritation & pain, this condition is said be acidityNaHCO3 (or) Mg(OH)2 are used as antacids to neutralise the  acid [HCl] produced in stomach.