Phenylephrine comes in several forms, including phenylephrine bitartrate (in effervescent tablet form), phenylephrine hydrochloride (in oral, nasal, injectable, cream, and eye drop forms), and phenylephrine tannate (in oral form). Because it comes in various forms, phenylephrine can be used for a variety of different purposes. This non-prescription medication is probably most commonly used as a nasal or sinus decongestant for relieving congestion and pressure due to allergies (such as hay fever) or the common cold.
Phenylephrine works by stimulating certain receptors known as alpha-adrenergic receptors. In the lining of the nose and sinuses, this action causes the blood vessels to constrict, allowing less fluid to leave the blood vessels and decreasing inflammation. This helps to relieve nasal and sinus congestion.
Although most people tolerate this medication well, it is not suitable for everyone. Before starting treatment with phenylephrine bitartrate, phenylephrine hydrochloride, or phenylephrine tannate, make sure to talk to your healthcare provider about any other medical conditions you may have or any other medications you are taking (including vitamins and herbal supplements). Some of the common side effects include insomnia, dizziness, and nervousness.
(Click Phenylephrine for a closer look at how this drug helps to relieve nasal and sinus congestion caused by allergies or the common cold. This article also covers general dosing guidelines and offers tips on when and how to use this medication.)