A patient has been prescribed an antacid and cimetidine. Which instruction should the nurse give about administration?

• A. Take the antacid 1 hour after the ranitidine.
• B. Take both medications at the same time.
• C. Take the antacid 15 minutes before ranitidine.
• D. Do not take antacid with ranitidine.

Answer: (A)

The key idea is to separate an antacid from an H2 blocker to avoid interference with absorption. Antacids neutralize stomach acid and raise pH, which can alter how quickly and how well drugs like ranitidine are dissolved and absorbed. By taking the antacid about 1 hour after the H2 blocker, you allow the H2 blocker to be absorbed first and then the antacid can be taken without risking reduced effectiveness. This spacing helps maintain consistent therapeutic levels and prompt symptom relief. Taking them together or too close in time can lessen the H2 blocker’s effect, while taking the antacid after an adequate interval supports proper absorption of the H2 blocker.