Warfarin Protocol for physicians
Dr. MuKeSh M. DeSaI. M.D.
HaEmAtOlOgY & ImMuNoLoGy CeLl
Consultant Hematologist & Oncologist & Immunologist
Sir Harkisondas Nurrotamdas Hospital
Balbhai Nanavati Hospital
Chief Division of Immunology
Prof of Pediatric Hematology & Oncology
Department of Pediatric Hematology Oncology
Bai Jerbai Wadia Hospital For Children; Mumbai.
E Mail: mmdesai007@gmail.com
Provisional Diagnosis:
Risk Factor:
Rx Plan:
· Anticoagulation management for 6 mths.
· Recheck tests if Necessary
·
Investigation Plan:
·
Final Diagnosis:
Rx Strategy:
Principles of Warfarinisation
Anticoagulation in a Patient with a Thrombotic Event:
§ Start LMWH:
§ injection Clexane 0.8 to 1.0 mg / Kg OD or BiD
§ Or
§ Injection Fraxiparine 0.8 to 0.1 ml / 10 kg OD or BiD
§ Severe Renal failure requires modification of dosage of LMWH.
§ Rx with LMWH can be done on out patient basis if patient does not have below mentioned Risk factors
§ Symptomatic Pulmonary Embolism.
§ Severe Renal failure.
§ Severe thrombocytopenia or major bleeding risk
§ General principles of Monitoring LMWH:
§ Start Warfarin 24 hrs after starting LM
§ Tab Warfarin 5 mg OD at 6.00 PM;
§ In Children dose of Warfarin is 0.1 to 0.2 mg/kg
§
§ Please note no loading dose
§ Measure PT/INR on day 5 and daily to maintain INR between 2.5 to 3.0
§ Target INR to be achieved and maintained at 2.5 to 3.0
§ Modification of dose of Warfarin depending on PT/INR on day 5 of warfarin.
§ If PT/INR > 3.0 decrease dose of Warfarin
§ If PT / INR < 2.5 increase dose of Warfarin
§ PT/INR testing frequency:
§ Weekly after each dosage change until 2 consecutive INRs are with in target range
§ Monthly thereafter as long as the INR remains in the target range.
§ As necessary when a medication is started or stopped that is documented to interact with Warfarin.
§ If a therapeutic range is to be maintained it is best to maintain INR in the middle region of that range.
§ Cease LMWH Clexane when the PT/INR has been greater than or equal to 2.5 on two consecutive days.
§ Please NOTE:
§ Length of Anticoagulation: 3 to6 mths / Life long.
§ Reevaluation: Repeat doppler after 3 to 6 mths.
Please do not hesitate to contact us in case u need any help
Please read about coumadin (Warfarin and you) before starting Rx.
NOTE:
§ IN CASE OF PLANNED SURGERY:
§ Omit Warfarin on Date: # i.e. 4 days prior to surgery &
§ Start LMWH inj Clexane 40 mg OD
§ Measure PT/INR 1 day prior to surgery on date #
§ INR < 1.2
§ Patient fit for surgery
§ If PT / INR > 1.2;
§ INR < 1.2 Patient fit for surgery
§ STOP inj Clexane 24 hrs before surgery.
§ SURGERY
§ Restart inj LMWH Injection Clexane 0.6 ml SC BD 12 hrs post surgery
§ Restart oral Warfarin once patient started on oral feeds
§ Restart Warfarin 5 mg once daily.
§ Measure PT/INR after 4 day on day 5
§ If PT/INR > 3.0 decrease dose of Warfarin
§ If PT / INR < 2.5 increase dose of Warfarin
§ Target INR to be achieved and maintained at 2.5 to 3.0.
§ Cease LMWH Clexane when the PT/INR has been greater than or equal to 2.5 on two consecutive days.
§ Please NOTE:
In case patient needs Urgent Surgery following protocol is suggested:
§ Measure PT/INR 1 IMMEDIATELY
§ INR < 1.2
§ Patient fit for surgery
§ If PT / INR > 1.2;
§ INR < 1.2 Patient fit for surgery / Induction of Labour
§ SURGERY / LSCS / Induction of Labour
§ Restart inj LMWH Injection Clexane 0.6 ml SC BD 12 hrs post surgery
§ Restart oral Warfarin once patient started on oral feeds
§ Restart Warfarin 5 mg once daily.
§ Measure PT/INR after 4 day on day 5
§ If PT/INR > 3.0 decrease dose of Warfarin
§ If PT / INR < 2.5 increase dose of Warfarin
§ Target INR to be achieved and maintained at 2.5 to 3.0.
§ Cease LMWH Clexane when the PT/INR has been greater than or equal to 2.5 on two consecutive days.
§ Please watch for bleeding, bruises.
Pregnancy & Anticoagulation:
q In Case of plannning a PREGNANCY PLEASE INFORM TREATING DOCTOR:
§ ONCE PREGNANCY CONFIRMED
Management in First Trimester of Pregnancy.
§ Omit Warfarin IMMEDIATELY.
§ To prevent Warfarin Embryopathy.
§ Start LMWN
§ Inj Clexane 20 to 40 mg OD Subcutaneously.
§ Or
§ Inj Fraxiparine 0.8 to 0.1 ml/10 kg OD Subcutaneously.
§ LMWH to be continued till 12 weeks of gestation
§ LMWH started in view of its efficacy and safety profile.
§ Anticoagulant effect
§ HIT ( Heparin Induced Thrombocytopenia )
§ Rewarfarinise patient as mentioned before.
§ Warfarin in Second and Third Trimester of Pregnancy is Safe
§ Warfarin Does NOT affect the fetus in Second Trimester.
§ Start Warfarin 5 mg once daily.
§ Take Warfarin at 6.00 pm in the evening.
§ Keep a constant Diet of vegetarian food.
§ Read about Warfarin and you before starting warfarin.
§ Measure PT/INR after 4 day on day 5
§ If PT/INR > 3.0 decrease dose of Warfarin
§ If PT / INR < 2.5 increase dose of Warfarin
§ Target INR to be achieved and maintained at 2.5 to 3.0.
§ Cease LMWH Clexane or Fraxiparine when the PT/INR has been greater than or equal to 2.5 on two consecutive days.
§ Monitoring of Warfarin
§ Monitor PT/INR initially weekly for 1 month.
§ Monitor PT/INR fortnightly for the entire course of pregnancy.
§ In case of Bleeding than to repeat PT/INR Urgently Immediately
§ Continue Warfarin till 36 weeks of gestation
§ OMIT warfarin and start LMWH Injection Clexane or Injection Fraxiparine as mentioned above.
§ Management of Labour
§ IN CASE OF EMERGENCY LABOUR.
§ INR < 1.2
§ Patient fit for Labour / LSCS
§ Restart inj LMWH Injection Clexane 0.6 ml SC BD 12 hrs post Delivery
§ Restart oral Warfarin once patient started on oral feeds
§ Restart Warfarin 5 mg once daily.
§ Measure PT/INR after 4 day on day 5
§ If PT/INR > 3.0 decrease dose of Warfarin
§ If PT / INR < 2.5 increase dose of Warfarin
§ Target INR to be achieved and maintained at 2.5 to 3.0.
§ Cease LMWH Clexane when the PT/INR has been greater than or equal to 2.5 on two consecutive days.
§ IN CASE OF PLANNED LABOUR OR SURGERY
§ Omit LMWH 24 hrs prior to induction of Labour
§ Omit LMWH IMMEDIATELY
§ Injection Protamine of Not great help to revert effect of LMWH
§ Measure Coagulation Profile IMMEDIATELY
§ Keep FFP (Fresh Frozen Plasma) arranged in case of unexpected Bleed.
§ STOP inj Clexane 24 hrs before surgery.
§ SURGERY
§ Restart inj LMWH Injection Clexane 0.6 ml SC BD 12 hrs post surgery
§ Restart oral Warfarin once patient started on oral feeds
§ Restart Warfarin 5 mg once daily.
§ Measure PT/INR after 4 day on day 5
§ If PT/INR > 3.0 decrease dose of Warfarin
§ If PT / INR < 2.5 increase dose of Warfarin
§ Target INR to be achieved and maintained at 2.5 to 3.0.
§ Cease LMWH Clexane when the PT/INR has been greater than or equal to 2.5 on two consecutive days.
§ IN CASE OF EMERGENCY SURGERY / LABOUR in Second / Third Trimester while patient on Warfarin
§ Omit Warfarin IMMEDIATELY
§ Measure PT/INR 1 IMMEDIATELY
§ INR < 1.2
§ Patient fit for surgery
§ If PT / INR > 1.2;
§ INR < 1.2 Patient fit for surgery / Induction of Labour
§ SURGERY / LSCS / Induction of Labour
§ Restart inj LMWH Injection Clexane 0.6 ml SC BD 12 hrs post surgery
§ Restart oral Warfarin once patient started on oral feeds
§ Restart Warfarin 5 mg once daily.
§ Measure PT/INR after 4 day on day 5
§ If PT/INR > 3.0 decrease dose of Warfarin
§ If PT / INR < 2.5 increase dose of Warfarin
§ Target INR to be achieved and maintained at 2.5 to 3.0.
§ Cease LMWH Clexane when the PT/INR has been greater than or equal to 2.5 on two consecutive days.
§ Please watch for bleeding, bruises.
please read about details on Warfarin before starting warfarin in any patient.
patient information is available at www.coumadin.com
Do Not Hesitate to Discuss the use of warfarin with your patient so that an untoward reaction can be prevented.
In case of any Bleed to CONTACT DOCTOR IMMEDIATELY.
Be Particular about Diet & vitamin K intake while patient is on Warfarin
In case any new Drug is added than BEWARE of DRUG INTERACTION with Warfarin.
If any PATIENT NEEDS MORE THAN > 15 mg Warfarin think of DRUG RESISTANCE.
IN CASE OF OTHER ANALOGUES OF Warfarin SIMILAR MONITORING IS NECESSARY.
GENETIC CAUSES OF POLYMORPHISM IN VKOR ENZYME RESULT IN VARIABILITY OF RESPONSE TO WARFARIN.
DONOT TAKE WARFARIN ADMINISTRATION TO PATIENT CASUALLY.
IN CASE OF NEED FOR REVERSAL WITH VTAMIN K THE DOSE OF VITAMIN K IS 0.5 mg to 1.0 mg I.V. in a Drip of 100 cc of Normal Saline over 20 to 30 minutes.
Vitakin K action is seen with in 8 to 12 hrs and a PT shoud be repeated at That TIME.