VITAMIN K1

Phytonadione is relatively nontoxic. However, severe reactions have occurred rarely and only during or immediately after the administration of the drug by the IV route. These reactions, which may occur in patients receiving phytonadione for the first time, resemble hypersensitivity or anaphylaxis.

Symptoms include cramp-like pains, convulsive movements, cardiac irregularities, chest pains, cyanosis, dulled consciousness, flushing of the face, a sense of chest constriction, circulatory collapse, bronchospasm, hyperhydrosis, dyspnea, alteration of taste, dizziness, rapid and weak pulse, brief hypotension, shock, cardiac and/or respiratory arrest, and death.

It is not known whether these adverse reactions are caused by the drug or the injection vehicle. Dilution and slow infusion ma y not prevent severe reactions; therefore, the IV route should be restricted to emergency use only. The possibility of allergic reactions, including anaphylaxis, should also be considered when phytonadione injection is given by the IM or SC routes.

Pain, swelling and tenderness at the injection site occur rarely after parenteral administration of phytonadione. Reactions resembling erythema perstans have been reported rarely after repeated injections. Hyperbilirubinemia and severe hemolytic anemia have been reported rarely in neonates, particularly in premature neonates, following the administration of large doses of phytonadione (10 to 20 mg).

However, the incidence of these adverse effects is much less with phytonadione than with other vitamin K preparations. html ) for information on how to report online, by mail or by fax; or • Calling toll-free at 1-866-234-2345.

NOTE:

Contact your health professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice. Vitamin K1 page 6 of

Phytonadione is relatively nontoxic. However, severe reactions, including fatalities, have been reported rarely and only during or immediately after the administration of the drug by the IV route. These severe reactions, which may occur in patients receiving phytonadione for the first time, resemble hypersensitivity or anaphylaxis (see ADVERSE REACTIONS).

Therefore, it is recommended that the IV route be restricted to those situations where other routes are not feasible and the serious risk involved is considered justified. Although it has not been reported , the possibility of an allergic reaction, including anaphylaxis, should be kept in mind when phytonadione is administered by the IM or the SC routes.

An immediate coagulant effect should not be expected after administration of vitamin K1. Since a delay of 3 hours or more may be required to stop active bleeding, administration of fresh, whole blood or plasma may be necessary when bleeding is severe.

Vitamin K1 will not counteract the anticoagulant action of heparin and will not return abnormal platelet function to normal. When vitamin K1 is used to correct excessive anticoagulant-induced hypoprothrombinemia in patients where anticoagulant therapy is still indicated, administration of excessive doses may restore the condition that originally required administration of anticoagulant drugs and large doses of coumarin or indanedione anticoagulants may be required to reinstate anticoagulant therapy.

In such patients, dosage of vitamin K1 should be kept as low as possible, and a regular monitoring of th e prothrombin time should be performed. If anticoagulation is needed following overdosage of phytonadione, heparin may be used.

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