Terfenadine Lansoprazole + Amoxicillin + Clarithromycin
ModerateStudies in healthy volunteers found that lansoprazole, one of the medicines in this combination, has no clinically significant interaction with terfenadine. The same was found for other medicines that the liver processes through the same enzyme system (cytochrome P450). So taking terfenadine alongside this medicine was not shown to cause a meaningful problem in those studies.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.