According to the drug description made in Bulgaria, it is safe with SSRI an SARI andtidepresants:
Ranitidin is a weak inhibitor of liver medicine metabolism. The simultaneous administration of Rantidin with oral anticoagulants, phenytoin, benzodiazepines, beta-blockers and theophyllin inhibits their elimination. During the simultaneous administration of Rantidin with anticoagulants should be controlled the prothrombin time and if possible to monitor plasma concentrations of the latter, in order to avoid eventual bleeding. Ranitidin inhibits the resorption of ketoconazole and antiacids, containing aluminium and magnesium. The simultaneous administration of Ranitidin with procainamide may reduce its excretion via the kidneys and as a result to increase the plasma concentration of procainamide.
If you want to be 100% sure than 1% sorry -> try Talcid or ordinary baking soda.