Vitamin K 1 5 MG Oral Tablet [Mephyton]
Generic Name: PHYTONADIONE
Brand Name: Mephyton
- Substance Name(s):
- PHYTONADIONE
WARNINGS
An immediate coagulant effect should not be expected after administration of phytonadione.
Phytonadione will not counteract the anticoagulant action of heparin.
When vitamin K1 is 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.
DRUG INTERACTIONS
Drug Interactions Temporary resistance to prothrombin-depressing anticoagulants may result, especially when larger doses of phytonadione are used.
If relatively large doses have been employed, it may be necessary when reinstituting anticoagulant therapy to use somewhat larger doses of the prothrombin-depressing anticoagulant or to use one which acts on a different principle, such as heparin sodium.
OVERDOSAGE
The intravenous and oral LD50s in the mouse are approximately 1.17 g/kg and greater than 24.18 g/kg, respectively.
DESCRIPTION
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: Mephyton (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.
Chemical Structure
HOW SUPPLIED
Product: 50090-1753 NDC: 50090-1753-0 5 TABLET in a BOTTLE
GERIATRIC USE
Geriatric Use Clinical studies of Mephyton did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.
Other reported clinical experience has not identified differences in responses between the elderly and younger patients.
In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
INDICATIONS AND USAGE
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.
PEDIATRIC USE
Pediatric Use Safety and effectiveness in pediatric patients have not been established with Mephyton.
Hemolysis, jaundice, and hyperbilirubinemia in newborns, particularly in premature infants, have been reported with vitamin K.
PREGNANCY
Pregnancy Animal reproduction studies have not been conducted with Mephyton.
It is also not known whether Mephyton can cause fetal harm when administered to a pregnant woman or can effect reproduction capacity.
Mephyton should be given to a pregnant woman only if clearly needed.
NUSRING MOTHERS
Nursing Mothers It is not known whether this drug is excreted in human milk.
Because many drugs are excreted in human milk, caution should be exercised when Mephyton is administered to a nursing woman.
DOSAGE AND ADMINISTRATION
Mephyton Summary of Dosage Guidelines (See circular text for details.) Adults Initial Dosage Anticoagulant-Induced Prothrombin Deficiency (caused by coumarin or indanedione derivatives) 2.5 mg-10 mg or up to 25 mg (rarely 50 mg) Hypoprothrombinemia Due to Other Causes (antibiotics; salicylates or other drugs; factors limiting absorption or synthesis) 2.5 mg-25 mg or more (rarely up to 50 mg) Anticoagulant-Induced Prothrombin Deficiency in Adults To correct excessively prolonged prothrombin times caused by oral anticoagulant therapy, 2.5 to 10 mg or up to 25 mg initially is recommended.
In rare instances 50 mg may be required.
Frequency and amount of subsequent doses should be determined by prothrombin time response or clinical condition.
(See WARNINGS.) If, in 12 to 48 hours after oral administration, the prothrombin time has not been shortened satisfactorily, the dose should be repeated.
Hypoprothrombinemia Due to Other Causes in Adults If possible, discontinuation or reduction of the dosage of drugs interfering with coagulation mechanisms (such as salicylates, antibiotics) is suggested as an alternative to administering concurrent Mephyton.
The severity of the coagulation disorder should determine whether the immediate administration of Mephyton is required in addition to discontinuation or reduction of interfering drugs.
A dosage of 2.5 to 25 mg or more (rarely up to 50 mg) is recommended, the amount and route of administration depending upon the severity of the condition and response obtained.
The oral route should be avoided when the clinical disorder would prevent proper absorption.
Bile salts must be given with the tablets when the endogenous supply of bile to the gastrointestinal tract is deficient.