Generally, these active ingredients are safe, even over several years. However, taking any medication for ten years warrants a review with your doctor. While major long-term risks are rare, montelukast can occasionally affect mood. It is best to consult your healthcare provider to see if you still need both ingredients daily. They might suggest transitioning to a single antihistamine like fexofenadine alone or using a generic steroid nasal spray, which are excellent, targeted alternatives.