Mephyton Recall

Get an alert when a recall is issued.

Questions & Answers

Side Effects & Adverse Reactions

An immediate coagulant effect should not be expected after administration of phytonadione.

Phytonadione will not counteract the anticoagulant action of heparin.

When vitamin K1is used to correct excessive anticoagulant-induced hypoprothrombinemia, anticoagulant therapy still being indicated, the patient is again faced with the clotting hazards existing prior to starting the anticoagulant therapy. Phytonadione is not a clotting agent, but overzealous therapy with vitamin K1 may restore conditions which originally permitted thromboembolic phenomena. Dosage should be kept as low as possible, and prothrombin time should be checked regularly as clinical conditions indicate.

Repeated large doses of vitamin K are not warranted in liver disease if the response to initial use of the vitamin is unsatisfactory. Failure to respond to vitamin K may indicate a congenital coagulation defect or that the condition being treated is unresponsive to vitamin K.

Legal Issues

There is currently no legal information available for this drug.

FDA Safety Alerts

There are currently no FDA safety alerts available for this drug.

Manufacturer Warnings

There is currently no manufacturer warning information available for this drug.

FDA Labeling Changes

There are currently no FDA labeling changes available for this drug.


MEPHYTON is indicated in the following coagulation disorders which are due to faulty formation of factors II, VII, IX and X when caused by vitamin K deficiency or interference with vitamin K activity.

MEPHYTON tablets are indicated in:

  • anticoagulant-induced prothrombin deficiency caused by coumarin or indanedione derivatives;
  • hypoprothrombinemia secondary to antibacterial therapy;
  • hypoprothrombinemia secondary to administration of salicylates;
  • hypoprothrombinemia secondary to obstructive jaundice or biliary fistulas but only if bile salts are administered concurrently, since otherwise the oral vitamin K will not be absorbed.


There is currently no drug history available for this drug.

Other Information

Phytonadione is a vitamin which is a clear, yellow to amber, viscous, and nearly odorless liquid. It is insoluble in water, soluble in chloroform and slightly soluble in ethanol. It has a molecular weight of 450.70.

Phytonadione is 2-methyl-3-phytyl-1, 4-naphthoquinone. Its empirical formula is C31H46O2 and its structural formula is:

Chemical Structure

MEPHYTON1 (Phytonadione) tablets containing 5 mg of phytonadione are yellow, compressed tablets, scored on one side. Inactive ingredients are acacia, calcium phosphate, colloidal silicon dioxide, lactose, magnesium stearate, starch, and talc.


Registered trademark of MERCK & CO., Inc. COPYRIGHT © 1986, 1991, MERCK& CO., Inc. All rights reserved

Mephyton Manufacturers

  • Rebel Distributors Corp
    Mephyton (Phytonadione) Tablet [Rebel Distributors Corp]
  • Pd-rx Pharmaceuticals, Inc.
    Mephyton (Phytonadione) Tablet [Pd-rx Pharmaceuticals, Inc.]
  • Physicians Total Care, Inc.
    Mephyton (Phytonadione) Tablet [Physicians Total Care, Inc.]
  • Valeant Pharmaceuticals North America Llc
    Mephyton (Phytonadione) Tablet [Valeant Pharmaceuticals North America Llc]
  • Kaiser Foundation Hospitals
    Mephyton (Phytonadione) Tablet [Kaiser Foundation Hospitals]
  • Cardinal Health
    Mephyton (Phytonadione) Tablet [Cardinal Health]
  • Carilion Materials Management
    Mephyton (Phytonadione) Tablet [Carilion Materials Management]

Login To Your Free Account