Which statement is true about these histamine H2 receptor antagonists?

Which statement is true about these histamine H2 receptor antagonists?

• A. Do not take with antacids
• B. Must be taken with antacids
• C. Only interact with NSAIDs
• D. Are antibiotics

Answer: (A)

Histamine H2 receptor antagonists lower acid secretion by blocking H2 receptors on parietal cells. Because antacids can change the stomach environment and alter drug absorption, taking them together can reduce how well the H2 blocker is absorbed and may lessen its effect. For this reason, it’s best to avoid taking an H2 receptor antagonist with an antacid or to space their dosing by a couple of hours. That’s why the statement about not taking them with antacids is true. These drugs are not antibiotics and their interactions aren’t limited to NSAIDs; they can interact with various other medications, so timing matters for effectiveness.