Vitamin K (Systemic)

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:

• Acetohydroxamic acid (e.g., Lithostat) or
• Antidiabetics, oral (diabetes medicine you take by mouth) or
• Dapsone or
• Furazolidone (e.g., Furoxone) or
• Methyldopa (e.g., Aldomet) or
• Nitrofurantoin (e.g., Furadantin) or
• Primaquine or
• Procainamide (e.g., Pronestyl) or
• Quinidine (e.g., Quinidex) or
• Quinine (e.g., Quinamm) or
• Sulfonamides (sulfa medicine) or
• Sulfoxone (e.g., Diasone) - The chance of a serious side effect may be increased, especially with menadiol

• Anticoagulants (blood thinners) - Vitamin K decreases the effects of these medicines and is sometimes used to treat bleeding caused by anticoagulants; however, patients receiving an anticoagulant should not take any supplement that contains vitamin K (alone or in combination with other vitamins or nutrients) unless it has been ordered by their doctor

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:

• Cystic fibrosis or other diseases affecting the pancreas or
• Diarrhea (prolonged) or
• Gallbladder disease or
• Intestinal problems - These conditions may interfere with absorption of vitamin K into the body when it is taken by mouth; higher doses may be needed, or the medicine may have to be injected

• Glucose-6-phosphate dehydrogenase (G6PD) deficiency - The chance of side effects may be increased, especially with menadiol
• Liver disease - The chance of unwanted effects may be increased