What are some common side effects of OTC antihistamines?
Healthy adults don’t usually experience side effects from antihistamines. However, side effects can be a concern for older adults or people who have health problems. First-generation antihistamines can make you feel very sleepy. This can affect your ability to drive or operate machines. It can also make it hard for you to think clearly. Antihistamines can cause your mouth and eyes to feel dry. They can also cause abdominal pain and headaches. Second-generation antihistamines are much less likely to cause these side effects.
