DECONGESTANTS VS ANTIHISTAMINES

Decongestant and anti-histamine medications are often confused and thought to have the same effects on the body. While there are similarities, these medications are not the same and do not act the same way on the body.

Decongestants relieve nasal congestion. They do this by causing the blood vessels in the nasal membranes to narrow. This reduces swelling, inflammation, and the amount of mucous produced by the nasal lining. Decongestants are most often used to treat colds and other respiratory infections, especially in people who easily develop middle ear or sinus infections. Many decongestants are available without a prescription. The most commonly used decongestants are pseudoephedrine and phenylephrine. Phenylpropanolamine (PPA), which was used in many products in the past, should be avoided because of a possible risk of stroke.

Antihistamines have a much broader use than decongestants. Antihistamines are used to calm a person, aid sleeping, suppress vomiting, and treat allergy symptoms. While they are used in cough and cold remedies with a decongestant, they are more often used to treat symptoms of allergic reactions, such as the sneezing and runny nose of hay fever and the itching, swelling, and redness of hives and other allergic rashes.

Antihistamines work by blocking the effect of a chemical called histamine that is produced by the body in response to an allergic reaction. Histamine makes small blood vessels widen in the skin, eyes, and nose. This causes redness and swelling. The most commonly used nonprescription antihistamine is diphenhydramine. There are also many antihistamines that can be prescribed only by a physician. They commonly cause less drowsiness than do those available without a prescription.

Both decongestants and antihistamines have some negative side effects. If decongestants are used for too long, they cause nasal congestion to worsen. Because decongestants constrict blood vessels, they are not recommended for people with:

heart disease
high blood pressure
glaucoma
thyroid disease
urinary retention problems or
certain people with asthma or diabetes

Antihistamines can make a person drowsy and dizzy. They also may cause loss of appetite, blurred vision, and a dry mouth. Antihistamines are not recommended for people with glaucoma, enlarged prostate, or high blood pressure.

People who take anti-depressant, sedative, hypnotic, or tranquilizer medications should not take antihistamines. Combining these drugs may cause negative side effects or complications to an existing medical problem. For example, antihistamines may cause an increased sedative effect for someone already taking a sedative.

Both decongestants and antihistamines can be purchased over-the-counter or by prescription. However, pregnant women should consult their healthcare provider before taking any over-the-counter medication. Other people, including those with medical conditions, are advised to read product labels carefully and consult a pharmacist if they have questions about use.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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