Generic Name: phenylephrine ophthalmic (fen ill EFF rin)
Brand Name: AK-Dilate, Altafrin, Mydfrin, Neofrin
What is Mydfrin (phenylephrine ophthalmic)?
Phenylephrine is a decongestant that shrinks blood vessels.
Phenylephrine ophthalmic (for the eyes) is used to relieve eye redness, dryness, burning, and irritation caused by wind, sun, and other irritants.
Prescription-strength phenylephrine ophthalmic is used to constrict blood vessels in the eye and to dilate (make bigger) the pupil for conditions such as glaucoma, before surgery, and before eye examinations.
Phenylephrine ophthalmic may also be used for purposes not listed in this medication guide.
What is the most important information I should know about Mydfrin (phenylephrine ophthalmic)?
You should not use phenylephrine ophthalmic if you have narrow-angle glaucoma.
What should I discuss with my healthcare provider before using Mydfrin (phenylephrine ophthalmic)?
You should not use phenylephrine ophthalmic if you are allergic to it, or if you have narrow-angle glaucoma.
Do not use phenylephrine ophthalmic without a doctor's advice if you have:
an eye infection;
an eye injury; or
if you have you have recently had eye surgery.
Any of the conditions above could cause your eyes to absorb phenylephrine ophthalmic into your body, which could lead to dangerous effects on the heart.
Ask a doctor or pharmacist if it is safe for you to use this medicine if you have other medical conditions, especially:
high blood pressure;
any type of heart condition;
coronary artery disease (hardened arteries); or
asthma or sulfite allergy.
FDA pregnancy category C. It is not known whether phenylephrine ophthalmic will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.
It is not known whether phenylephrine ophthalmic passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
Do not give this medicine to a child without medical advice.
How should I use Mydfrin (phenylephrine ophthalmic)?
Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.
Wash your hands before using the eye drops.
To apply the eye drops:
Tilt your head back slightly and pull down your lower eyelid to create a small pocket. Hold the dropper above the eye with the tip down. Look up and away from the dropper and squeeze out a drop.
Close your eyes for 2 or 3 minutes with your head tipped down, without blinking or squinting. Gently press your finger to the inside corner of the eye for 2 to 3 minutes, to keep the liquid from draining into your tear duct.
Use only the number of drops your doctor has prescribed, or as recommended on the medicine label. If you use more than one drop, wait about 5 minutes between drops.
Wait at least 10 minutes before using any other eye drops your doctor has prescribed.
Do not touch the tip of the eye dropper or place it directly on your eye. A contaminated dropper can infect your eye, which could lead to serious vision problems.
Do not use the eye drops if the liquid has changed colors or has particles in it. Call your pharmacist for new medicine.
Your blood pressure may need to be checked while you are using phenylephrine ophthalmic.
Do not use this medicine for longer than 3 days. Call your doctor if your symptoms do not improve, or if they get worse while using phenylephrine ophthalmic.
Long-term use of phenylephrine ophthalmic may damage the blood vessels (veins and arteries) in the eyes.
Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.
What happens if I miss a dose?
Apply the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next dose. Do not use extra medicine to make up the missed dose.
What happens if I overdose?
An overdose of phenylephrine ophthalmic is not expected to be dangerous. Seek emergency medical attention or call the Poison Help line at 1-800-222-1222 if anyone has accidentally swallowed the medication.
What should I avoid while using Mydfrin (phenylephrine ophthalmic)?
Do not use this medicine while wearing contact lenses. Phenylephrine ophthalmic may contain a preservative that can discolor soft contact lenses. Wait at least 15 minutes after using this medicine before putting in your contact lenses.
This medicine may cause blurred vision and may impair your reactions. Be careful if you drive or do anything that requires you to be able to see clearly.
Mydfrin (phenylephrine ophthalmic) side effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Although the risk of serious side effects is low when phenylephrine ophthalmic is used in the eyes, side effects can occur if the medicine is absorbed into your bloodstream. Stop using phenylephrine ophthalmic and call your doctor at once if you have:
fast or irregular heart rate;
pale skin, light-headed feeling;
severe headache, buzzing in your ears, anxiety, shortness of breath; or
chest pain or pressure, pain spreading to your jaw or shoulder.
Less serious side effects may be more likely, and you may have none at all.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What other drugs will affect Mydfrin (phenylephrine ophthalmic)?
Tell your doctor if you have used an MAO inhibitor in the past 21 days. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.
Other drugs may interact with phenylephrine ophthalmic, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.
See also: Side effects (in more detail)
More about Mydfrin (phenylephrine ophthalmic)
- Side Effects
- Dosage Information
- Drug Interactions
- Support Group
- En Español
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- Drug class: mydriatics
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Where can I get more information?
- Your pharmacist can provide more information about phenylephrine ophthalmic.
- Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
- Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2012 Cerner Multum, Inc. Version: 7.01.
Last reviewed: March 14, 2014
Date modified: August 01, 2017