Try switching antihistamines if one stops working

What to Do

If your current antihistamine feels less effective after prolonged use, switch to a different one for a few weeks, then switch back.

Why It Works

While true pharmacological tolerance to antihistamines is debated, many patients report diminished effectiveness over time. Rotating between cetirizine, loratadine, and fexofenadine can restore perceived effectiveness. Each has slightly different receptor binding characteristics.

Tips

• Give each antihistamine at least 2-3 days to assess effectiveness
• If none of the three provide adequate relief, consider adding a nasal corticosteroid spray rather than doubling the antihistamine dose
• Do not exceed the recommended dose of any single antihistamine