Can you use zantac and rennies together?

Zantac (ranitidine) and Rennies (antacids containing calcium carbonate or magnesium trisilicate) can generally be used together, as they work in different ways to relieve heartburn and indigestion. Zantac reduces stomach acid production, while Rennies neutralizes existing stomach acid. However, it's important to space them out; taking Rennies shortly after Zantac may reduce the effectiveness of Zantac. Always consult a healthcare professional before combining medications.