antihistamine decongestant combination

Antihistamine and decongestant combinations are used to treat the nasal congestion (stuffy nose), sneezing, and runny nose caused by colds and hay fever. Basically, antihistamines work by preventing the effects of a substance called histamine, which is produced by the body. It is worth noting that histamine can cause itching, sneezing, runny nose, and watery eyes. As for decongestants, they produce a narrowing of blood vessels. This leads to clearing of nasal congestion, but it may also cause an increase in blood pressure in patients who have high blood pressure. Some of these antihistamine-decongestant combinations are available only with your doctor's prescription. Others are available without a prescription; however, your doctor may have special instructions on the proper dose of the medicine for your medical condition. Just remember that you must not give any over-the-counter cough and cold medicine to a baby or child under 2 years of age, because using these medicines in very young children might cause serious or possibly life-threatening side effects.