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Vitamin K  (Systemic)

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Brand Names

Some commonly used brand names are:

In the U.S.—

  • AquaMEPHYTON2
  • Mephyton2

Note:

For quick reference, the following medicines are numbered to match the corresponding brand names.

Other commonly used names are: phylloquinone; phytomenadione; vitamin K1; vitamin K4.

This information applies to the following medicines:
1.  Menadiol (men-a-DYE-ole)*
2.  Phytonadione (fye-toe-na-DYE-one)
‡  Generic name product may be available in the U.S.
§  Generic name product may be available in Canada
*  Not commercially available in the U.S.
†  Not commercially available in Canada

Category


Description

Vitamins (VYE-ta-mins ) are compounds that you must have for growth and health. They are needed in only small amounts and usually are available in the foods that you eat. Vitamin K is necessary for normal clotting of the blood.

Vitamin K is found in various foods including green leafy vegetables, meat, and dairy products. If you eat a balanced diet containing these foods, you should be getting all the vitamin K you need. Little vitamin K is lost from foods with ordinary cooking.

If you are taking anticoagulant medicine (blood thinners), the amount of vitamin K in your diet may affect how well these medicines work. Your doctor or health care professional may recommend changes in your diet to help these medicines work better.

Lack of vitamin K is rare but may lead to problems with blood clotting and increased bleeding. Your doctor may treat this by prescribing vitamin K for you.

Vitamin K is routinely given to newborn infants to prevent bleeding problems.

This medicine is available only with your doctor's prescription, in the following dosage forms:



Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For vitamin K, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to vitamin K. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Vitamin K has not been reported to cause birth defects or other problems in humans. However, the use of vitamin K supplements during pregnancy is not recommended because it has been reported to cause jaundice and other problems in the baby.

Breast-feeding—Vitamin K taken by the mother has not been reported to cause problems in nursing babies. You should check with your doctor if you are giving your baby an unfortified formula. In that case, the baby must get the vitamins needed some other way.

Children—Children may be especially sensitive to the effects of vitamin K, especially menadiol or high doses of phytonadione. This may increase the chance of side effects during treatment. Newborns, especially premature babies, may be more sensitive to these effects than older children.

Older adults—Many medicines have not been tested in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information about the use of vitamin K in the elderly.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking vitamin K, it is especially important that your health care professional know if you are taking any of the following:

Other medical problems—The presence of other medical problems may affect the use of vitamin K. Make sure you tell your doctor if you have any other medical problems, especially:


Proper Use of This Medicine

Take this medicine only as directed by your doctor. Do not take more or less of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may cause serious unwanted effects, such as blood clotting problems.

Dosing—

The dose of these medicines will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets or injections that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are taking the medicine.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses. Tell your doctor about any doses you miss.

Storage—

To store this medicine:


Precautions While Using This Medicine

Tell all medical doctors and dentists you go to that you are taking this medicine.

Always check with your health care professional before you start or stop taking any other medicine. This includes any nonprescription (over-the-counter [OTC]) medicine, even aspirin. Other medicines may change the way this medicine affects your body.

Your doctor should check your progress at regular visits. A blood test must be taken regularly to see how fast your blood is clotting. This will help your doctor decide how much medicine you need.


Side Effects of This Medicine

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.


Revised: 01/17/2002

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