Phenylephrine is a medication that comes in several forms and is used for a variety of different purposes. It 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.
As with any medicine, phenylephrine can cause side effects.
However, not everyone who takes the drug will experience bothersome side effects. Some people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or are easily treated by you or your healthcare provider. Serious side effects are less common.
Possible side effects of phenylephrine include, but are not limited to:
(Click Phenylephrine Side Effects to learn more, including potentially serious side effects that you should report immediately to your healthcare provider.)
What Should I Tell My Healthcare Provider Before Taking Phenylephrine?
You should talk with your healthcare provider prior to taking this medication if you have:
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
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.
In the blood vessels of the body, this action causes an increase in
blood pressure, which is why the medication is used in emergency situations to increase dangerously low blood pressure. In the eye, phenylephrine causes dilation of the pupil, constriction of the blood vessels, and a decongestant action.
Some general considerations include the following:
- For oral forms of this medication, it does not matter if you take phenylephrine with food or on an empty stomach. If the medication seems to bother your stomach, try taking it with a little food.
- Because there are several different phenylephrine products available, make sure to follow the instructions for your particular product.
- Some people find that phenylephrine interferes with their ability to fall asleep. If you experience this problem, try taking your last dose earlier in the day.
- For the medication to work properly, it must be taken as directed.
Dosing Information for Phenylephrine
The recommended dose of phenylephrine will vary, depending on a number of factors, including:
- The particular product
- The medical condition being treated
- Your age
- Other medications you are taking
- Other medical conditions you may have.
As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
What If I Take an Overdose?
An overdose with phenylephrine can cause serious problems. If you happen to overdose on this medication, seek immediate medical attention.
In general, phenylephrine should be stored at room temperature, away from moisture and heat. Keep this and all other medications out of the reach of children.
What Should I Do If I Miss a Dose of Phenylephrine?
For people who take this medication on a regular schedule, take your missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose of phenylephrine.
