Is it safe to use antihistamines every day? In general, most of the available over-the-counter antihistamines are safe for long-term use. There are some potential side effects and there are some cases where long-term antihistamine use can worsen urinary retention or narrow angle glaucoma.
But I think one of the biggest risks is that patients start using these antihistamines every day and sometimes forget they're on them, and they can then interact with other medications that your physician could prescribe you. So it's really important to work with your physician when you're using any medication for a prolonged period of time.
I think it's also important to know that there are therapies called immunotherapy, which can actually desensitize you to your allergy triggers. So hopefully you don't have to use as many antihistamines. If you'd like to learn more, we'd love to work with you. Thanks!