Interactions with other medications besides allergy medicine?

What other prescription drugs interact with this medication?

Drug interactions occur when one medicine changes the way another works. This can raise levels of either drug in the body, increase side effects, or reduce effectiveness. For many common allergy treatments, major interactions involve antifungal agents, certain antibiotics, and HIV protease inhibitors.

How do these interactions change drug levels in the body?

Some medications inhibit enzymes responsible for breaking down the active ingredient. Enzyme inhibition keeps the allergy drug in the system longer, boosting exposure and risk of cardiac or nervous-system effects. Enzyme-inducing drugs shorten its half-life, making esomeprazole or other proton-pump inhibitors sometimes used to stabilize levels.

Can over-the-counter products cause problems too?

Yes. Antacids alter gastric pH and can lower absorption of certain allergy compounds. Grapefruit juice blocks same enzymes as some antibiotics, raising blood levels of the drug. St. John's wort accelerates metabolism and reduces efficacy.

When does patent protection end for competing versions?

Current estimates point to 2026 for basic composition patents, with regulatory exclusivities extending through 2027. Biosimilar or generic challengers begin filing Paragraph IV certifications against the originator after 2025.