ome of the main side effects of antihistamines include:
Dry mouthDrowsinessDizzinessNausea and vomitingRestlessness or moodiness (in some children)Trouble peeing or not being able to peeBlurred visionConfusionIf you take an antihistamine that causes drowsiness, do so before bedtime. Don’t take it during the day before you drive or use machinery.
Read the label before you take an allergy drug. Antihistamines may interact with other medications you are taking.