Warfarin (Western General Hospital)

Prescribing Warfarin in the Outpatient Dialysis Unit – Western General Hospital

1st contacts

M/W/F patients

Dr Caroline Whitworth

 Please email unless urgent

T/T/S patients

Dr Heather Kerr

Please email unless urgent 

Preferred email heather.kerr@nhs.net
2nd contact

Dr Sundeep Miya

Bleep 5221 at RIE
3rd contact (out-of-hours or if 1st or 2nd contacts unavailable)

Renal Registrar on-call via RIE switchboard
  • INRs should only be checked WEEKLY on a Monday or Tuesday unless there are clinical concerns (eg: unusual bleeding at fistula site, prolonged nose bleeds, unusual extensive bruises, malaena etc) or when instructed by a prescriber
  • Understanding the patient’s anticoagulation history is key to safe prescribing. Consistency in prescribing is essential and is best achieved by maintaining the same prescriber for all occasions as much as possible
  • If INR remains within target range please contact prescriber on the next working day. The patient should continue with his/her usual warfarin dose until further prescription advice is obtained
  • All enquiries to Renal Registrar on-call during the out-of-hours period or in the weekend MUST be done via the Nurse In-charge of the Dialysis Unit at the time. The on-call registrar should NOT be routinely contacted for warfarin prescriptions except in unsafe situations as below:
  • INR >4
  • Active bleeding
  • For sub-therapeutic INRs in the following situations, the prescriber should be contacted for advice:
    • Patients with a metallic heart valve when INR is <2.0
    • Patients with lupus anticoagulant when INR is <1.5
    • Patients with venous thromboembolism (PE/DVT) when INR is <1.5
  • Patients with stable INRs will require less frequent monitoring. They should continue their usual warfarin dose unless it is unsafe (as described above)
  • Frequency of INR monitoring should be specified by the prescriber


Written by: Jin Hah, Clinical Pharmacist
Reviewed by: Dr Caroline Whitworth, Associate Clinical Director/Consultant Nephrologist
Date written: September 2018
Review date: September 2020