vitamin K-1, phytonadione (Mephyton)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

GENERIC NAME: vitamin K-1, phytonadione

BRAND NAME: Mephyton

DISCONTINUED BRAND: AquaMephyton in the US

DRUG CLASS AND MECHANISM: Phytonadione is a synthetic form of vitamin K that is chemically identically to the naturally occurring vitamin K. Vitamin K is found in many foods from both plant and animal sources. Common sources of vitamin K include green leafy vegetables such as

  • broccoli,
  • Brussels sprouts,
  • collard greens,
  • lettuce, and
  • spinach.

Vitamin K plays a crucial role in blood coagulation and the formation of blood clots. Vitamin K is necessary for the production of clotting factors in the liver including active prothrombin (factory II), proconvertin (factor VII), plasma thromboplastin component (factor IX), and Stuart factor (factor X). The FDA approved phytonadione 1940.

PRESCRIBED FOR: Vitamin K is used to prevent and treat hypoprothrombinemia (deficiency of factor II or prothrombin) and bleeding caused by warfarin (Coumadin), a commonly used blood thinner. It is also used to treat and prevent drug induced vitamin K deficiency caused by other medications. Additionally, it is used to prevent and treat bleeding disorders in newborns and to replace low levels of vitamin K caused by malabsorption or inability to synthesize vitamin K.

SIDE EFFECTS: Serious hypersensitivity reactions, including anaphylactoid reactions and death have been reported with use of injectable phytonadione. The majority of these cases were associated with use of intravenous phytonadione.

Other side effects reported with use of injectable phytonadione include:

Medically Reviewed by a Doctor on 6/12/2015
FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

RxList Logo

Need help identifying pills and medications?

Use the pill identifier tool on RxList.

Subscribe to MedicineNet's Newsletters

Get the latest health and medical information delivered direct to your inbox!

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Health Solutions From Our Sponsors