Phytonadione / Vitamin K
Liverpool Hospital Emergency Department
- Reverse drug induced Vit K deficiency
- Warfarin OD intentional
- Therapeutic Over- Warfarinisation
- “Superwarfarin” Anticoagulant Rodenticide Overdose
- 10ml/1ml -> Konakion – Given IV
- 10mg Capsule – PO
- 2mg/0.2ml ampule – Konakion Paediatric
Dosage and Administration
- Active life-threatening uncontrollable haemorrhage:
- 5-10mg IV bolus
- Warfarin Overdose (ingestion of <0.5mg/kg usually benign in those not on warfarin)
- Not on regular warfarin:
- Measure baseline INR prior to vitamin K.
- 10-20mg (paediatric 0.25mg/kg up to 20mg) po or IV. (delay po vit k for 4 hours if AC given)
- Repeat INR every 24 hours.
- Further 10-20mg if INR >1.4. Generally, no further treatment required after 3 days.
- No further INR testing is needed once INR<1.4 on 2 consecutive days
- Therapeutic warfarin use: Caution with over correction due to risk of clotting.
- Follow eTG management of bleeding and over anticoagulation.
- Monitor INR every 6 hours
- Give Vitamin K if INR>5 0.5-2mg IV
- Repeat doses if remains or returns to >5
- Start heparin if INR falls <2 and absolute indication for anticoagulation e.g. heparin
- Paediatric Overdose:
- <0.5mg/kg no treatment needed.
- 0.5-1mg/kg 1 dose 10mg vit K po with no investigations
- >1mg/kg 10mg Vit K po for 3 days
- Superwarfarin Overdose
- Large doses may be required
- Duration of therapy might be protracted
- Do not give Vitamin K until anticoagulation has occurred
- INR >2 use 20-100mg orally or IV BD
- *INR >10 the higher end of dose range should be used
- Measure INR daily until <2
- Monitor weekly after discharge unless INR >2
- Continue Vitamin K for at least 1 month
- Anaphylaxis – Increased risk if given IV
- Facial flushing, sweating
- Venous irritation /phlebitis
- Safe in pregnancy
- Takes 6hrs to work – so not an immediate intervention
- Contraindicated if known hyper-sensitivity
- Certain patients may be suitable for outpatient INR monitoring
- Those that are unlikely to be compliant / concerns regarding DSP / at risk of complications require inpatient management
- FFP and Prothrombin X if actively bleeding