Tablets, injection
Vitamin K is used to prevent or treat bleeding disorders resulting from reduced formation of proteins needed for blood coagulation. The need may be due either to vitamin K deficiency or impairment of its function by anticoagulant drugs such as warfarin, salicylates, and some antibiotics. Vitamin K does not overcome the anticoagulant effects of heparin. Because vitamin K is normally made by bacteria in the intestine, dietary deficiency is rare. Bile salts are needed for absorption of vitamin K from the intestine, so absorption may be poor when obstruction of the bile ducts prevents entry of bile salts into the intestine. In newborns, the American Academy of Pediatrics recommends administration of phytonadione at birth to prevent bleeding disorders that can occur because adequate amounts of vitamin K may fail to cross the placenta from the mother to the fetus, and newborns have no bacteria in their intestines at birth. In people receiving all nutrition by injection for long periods, intramuscular injections of vitamin K are needed.
Vitamin K is necessary before a number of blood coagulation factors can become active in preventing or stopping bleeding.
Oral doses-- Menadiol sodium phosphate: Adults: For obstruction of bile duct: 5 mg a day. For problems related to use of antibacterials or salicylates: 5 to 10 mg a day. Children: 5 mg a day. Phytonadione: Adults: 2.5 to 10 mg (but up to 25 mg) if needed; can be repeated after 12 to 48 hours. Injections-- Menadiol sodium phosphate: Adults: 5 to 15 mg once or twice a day. Children: 5 to 10 mg once or twice a day. Phytonadione: Adolescents and adults: 2.5 to 25 mg; can be repeated if necessary. Children: 5 to 10 mg. Infants: 1 to 2 mg. During long-term total parenteral (intravenous) nutrition: Adults: 5 to 10 mg a week. Children: 2 to 5 mg a week.
Oral phytonadione: six to 12 hours. Injected phytonadione: one to two hours. Injected menadiol sodium phosphate: eight to 24 hours.
12 to 24 hours
No interactions. The best dietary sources of vitamin K are leafy green vegetables, meats, and dairy products.
Store in a cool dry place away from light. Avoid allowing injectable forms to freeze.
Take as soon as remembered unless close to next dose. Do not double the next dose.
Do not stop taking vitamin K unless instructed to do so by your doctor.
Prolonged use is uncommon; no problems are expected at recommended doses.
No information is available on the effects of age on vitamin K doses.
No special precautions are necessary.
No special precautions are necessary.
No information is available.
No problems have been reported.
Caution is required with vitamin K injections in newborns because of the risk of anemia and liver toxicity.
The smallest effective dose should be given to overcome bleeding due to an overdose of anticoagulant. Too large a dose may delay the subsequent action of the anticoagulant. Laboratory tests of clotting function (prothrombin time) are needed to determine the proper dose of vitamin K.
No specific ones have been reported.
Emergency instructions not applicable.
Antacids, antibiotics, and sucralfate can decrease vitamin K absorption. Vitamin K can interfere with the action of drugs like salicylates and anticoagulants. Other drugs may interact with vitamin K; consult your doctor if you are taking any prescription or over-the-counter drug.
None reported.
Caution is advised in people with liver disease.
