Conversation: The conversation between human and AI assistant.
[|Human|] Hello...I was just trying to explain, in simple terms what the difference is between antihistamines/what they do/how they work/possible side effects and the same for decongestants....I wonder if there s a simple article that does this better than I can that I can send to her...thanks much and have a great weekend...my best, tony miller
[|AI|]  Hello and thank you for using Chat Doctor. Antihistamines, as the name suggests, are used to target histamine which are an important chemical mediator of allergic reaction. Antihistamines act best when they are given before exposure to allergy causing agent or environment. If the histamine is mot released, then most of the allergic reactions don't occur or reduce in severity. Depending on the type of antihistamines, different side effects can be seen such as sleepiness(avoid Chat Doctor. Decongetants are simply medicines which prevent the stuffiness and running of nose which is common with most of allergic condition. Decongestants are to be avoided in a patient with cardiac problem, prostatic enlargement. Chronic use of decongestants can lead to rebound increase in nasal congestion. So it is always advised to take decongestants in short intervals both are available as, tablets, syrups,