Antihistamines are
medications used to prevent or
treat allergy symptoms. Many of
these medicines may be bought
without a doctor's prescription. The American Academy of
Family Physicians has issued
these guidelines for people
who take an over-the-counter
antihistamine: Before you take an
antihistamine, talk to your
doctor if you have a chronic
health condition, including
heart disease, high blood
pressure or thyroid disease. Before you take an
antihistamine, talk to your
doctor if you also take a
sleeping pill, sedative or
muscle relaxant. These other
medicines may interact with an antihistamine. If you take an antihistamine
that is combined with a
decongestant or pain
reliever, carefully check the
label for potential
interactions with your other medications. Be careful that you aren't
taking more than one
medication that contains an
antihistamine. This could
cause you to take more than
you need