MedicinePOMEssential

Vitamin K1

An injectable form of vitamin K (phytonadione) used to treat bleeding problems from vitamin K deficiency.

Clinical information

Common uses

reversing low clotting factors caused by warfarin-type anticoagulants
low clotting factors from poor vitamin K absorption or antibiotics
preventing and treating vitamin K-deficiency bleeding in newborns

Common side effects

dizziness
flushing
sweating
changes in taste
fast heartbeat

Cautions

fatal allergic reactions have occurred with IV or IM injection (boxed warning)
under-the-skin route preferred over IV or IM where possible
benzyl alcohol preservative can seriously harm newborns and infants
skin reactions can occur with injection

Interactions

warfarin-type anticoagulants — vitamin K1 can temporarily block their effect
heparin — its action is not affected

Pregnancy: only if needed — preservative-free form preferred

Reference information, not medical advice — always follow your doctor or pharmacist. Source: DailyMed, dailymed.nlm.nih.gov, Vitamin K1 (phytonadione) injection label, setid e8808230-2c44-44c6-8cab-8f29b6b34051 (accessed 2026-08-16)

Approved brands & formulations7

Brand name	Dosage form	Strength	Importer	Category
Kenadion 1	Parenteral ( Injection )	1 mg/0.5 ml	authorized medicine importers	POM
Konakion	Parenteral ( Injection )	2mg/0.2ml	authorized medicine importers	POM
Menadione	Parenteral ( Injection )	10 mg	authorized medicine importers	hospital
Phytomenadione	Parenteral ( Injection )	10mg/ml	MFDA designated importers with Pre Authorization approval before import	hospital
Phytomenadione	Tablet	10mg	—	POM
Phytomenadione (Vitamin K1)	Parenteral ( Injection )	1 mg/0.5 ml	—	POM
Vitamin KC5522:M5524	Parenteral ( Injection )	—	—	POM