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Mephyton (oral/injection)

Generic Name: phytonadione (oral/injection) (fye toe na DYE own)
Brand Name: Aquamephyton, Konakion, Mephyton, Vitamin K1

Medically reviewed on March 13, 2018

What is Mephyton?

Mephyton is a man-made form of vitamin K, which occurs naturally in the body.

Mephyton is used to treat vitamin K deficiency, and to treat certain bleeding or blood-clotting problems caused by other medicines or medical conditions.

Mephyton may also be used for purposes not listed in this medication guide.

Important Information

Never use Mephyton in larger amounts, or for longer than recommended by your doctor.

A Mephyton injection may cause a serious allergic reaction. Tell your caregiver if you feel weak, tingly, light-headed, warm, itchy, or if you have a chest pain, trouble breathing, a cold sweat, or swelling in your face.

Before taking this medicine

You should not use Mephyton if you are allergic to it.

Tell your doctor if you have ever had liver disease.

Mephyton injection may contain an ingredient that can cause serious side effects or death in very young or premature babies. Do not give Mephyton to a child without medical advice.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It may not be safe to breast-feed a baby while you are using this medicine. Ask your doctor about any risks.

How should I use Mephyton?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Never use Mephyton in larger amounts, or for longer than prescribed.

A Mephyton injection is given into a muscle, under the skin, or as an infusion into a vein. A healthcare provider will give the injection.

You may need frequent blood tests.

If you need surgery or dental work, tell the surgeon or dentist you currently use this medicine.

Store at room temperature away from moisture and heat. Protect from light. Keep the medicine in the original container and tightly closed when not in use.

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose of Mephyton.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Mephyton?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Mephyton side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

A Mephyton injection may cause a serious allergic reaction. Tell your caregiver if you feel weak, tingly, light-headed, warm, itchy, or if you have a chest pain, trouble breathing, a cold sweat, or swelling in your face.

Call your doctor at once if you have:

  • unusual or unpleasant taste in your mouth;

  • a light-headed feeling, like you might pass out;

  • blue colored lips;

  • jaundice (yellowing of the skin or eyes);

  • trouble breathing;

  • weak but rapid pulse; or

  • skin redness, itching, or a hard lump where an injection was given.

Common side effects may include:

  • dizziness;

  • flushing (warmth, redness, or tingly feeling);

  • changes in your sense of taste;

  • sweating; or

  • pain or swelling where the medicine was injected.

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.

See also: Side effects (in more detail)

What other drugs will affect Mephyton?

Tell your doctor about all your other medicines. Some may affect Mephyton, especially:

This list is not complete. Other drugs may affect Mephyton, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

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.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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