There are a variety of over-the-counter (OTC) products that may be used for a runny or stuffy nose and sinus drainage. The two primary types of medications include antihistamines and oral decongestants.

Antihistamines may be used to treat "runny nose" symptoms and are commonly found in allergy or cough and cold products. Examples of common OTC antihistamines include diphenhydramine HCl.They work by blocking histamine, a chemical that is released in the body. Histamine can cause itchy, watery eyes, runny nose, and other symptoms commonly seen with hay fever and other types of allergies. The most common side effect of antihistamines is drowsiness.

There are certain medications that may interact with antihistamines to produce a more sedating effect. These medicines include but are not limited to alcohol and CNS depressants (e.g., sleep aids, medications used to treat anxiety). In addition, antihistamines should be used with caution with certain medical conditions. Some of these include enlarged prostate, urinary problems, and glaucoma. If you have a medical condition other than hay fever or allergies or are currently taking other medications, please discuss with you physician or pharmacist before starting therapy with antihistamines.

Decongestants are used to help treat a stuffy nose. Decongestants help by reducing swollen mucous membranes and nasal congestion, making it easier to breathe. However, these products should be used with caution by certain persons. If you have any of the following conditions, please discuss with your physician before taking any OTC medication containing decongestants: diabetes, high blood pressure, heart disease, glaucoma, enlarged prostate, or overactive thyroid. Examples of decongestants are pseudoephedrine and phenylephrine.

Source: www.WebMD.com , www.Walgreens.com