Warfarin Dosing Service

1. If your patient is a community resident and meets the preconditions outlined here, complete the online “Referring Practitioner’s Warfarin Dosing Application Form” here.
2. If your patient is a RACF resident and meets the preconditions outlined here, then complete the online “Referring Practitioner’s Warfarin Dosing Application Form” here.
3. Upon submission of this “Referring Practitioner’s Warfarin Dosing Application Form”, 4Cyte will automatically send a link via SMS / email to the patient. The patient is then required to complete the “Patient’s Warfarin Dosing Application Form.”
4. Both the doctor-completed “Referring Practitioner’s Warfarin Dosing Application Form” and the patient-completed “Patient’s Warfarin Dosing Application Form” must be received by 4Cyte before a patient can be considered for acceptance into our warfarin dosing service.
5. Once 4Cyte accepts the patient into the lab-dosed warfarin service, 4Cyte will issue that patient with a current warfarin service enrolment number via SMS. This enrolment number should be retained by the patient and quoted at each future INR testing attendance.
6. Once 4Cyte accepts the patient into the lab-dosed warfarin service, 4Cyte will issue the managing general practitioner with written advice to that fact.
7. Dr to issue patient with two pathology request forms:
• A request for “FBC & E/LFT”
• A request for “INR – 4Cyte lab dosing – Rule 3 Exemption”
8. Once patients have had their INR blood collected, the 4Cyte dosing service will send the patient via SMS, their INR result, and dosing recommendations generally within 24 hours but sometimes up to 48 hours post testing. For patients who are residents of RACF, results will be sent to the nominated aged care facility. Results and dosing recommendations will be simultaneously sent to the patient’s general practitioner.

What the dosing service does (and doesn’t do):

• Does: Interprets each INR in context, gives dose instructions and a next-test date, screens for red-flags at each INR collection, sends dose instructions by SMS to the patient (fax to RACF) and by download to the patient’s general practitioner.
• Does not: Replace the general practitioner’s overall clinical care. The general practitioner (or the original referrer) remains responsible for patient management, indication, target INR range, intended duration, and peri-procedural plans etc.

Key Accountabilities:

• 4Cyte’s dosing advice is a laboratory-based recommendation; the general practitioner’s authority remains as overall prescriber/clinician of record.
• You (GP/specialist): clinical ownership, prescriptions, setting/changing range or duration, peri-op decisions, compliance, patient education and awareness, switching therapy (e.g. to DOAC), abnormal results, and handling complex comorbidity. You are responsible for ensuring the patient attends their scheduled next tests dates as recommended by 4Cyte.
• 4Cyte dosing service: protocol-based dose advice + scheduling, recording, patient question and answer at time of collection, timely communication, escalation to managing general practitioner per thresholds.
• Patient/RACF: follow the dose, attend scheduled tests, report medicine/illness/diet changes, keep a record.

Very High INRs:

• For very high INRs, 4Cyte will follow set escalation procedures and alert you by Fax (>4.0) and or SMS (>4.9) according to our established thresholds.

Documentation you will receive from 4Cyte:

• Enrolment confirmation.
• You will receive from 4Cyte for each INR: result, dose, next INR date.
• Notice of discharge of patient into your dosing management when patient discharged from 4Cyte dosing service.

4Cyte dosing service is not suitable for some patients:

• Patients with poor monitoring, access, adherence, high variability and or labile INRs.
• Those patients who cannot be safely catered for with an “electronic” dosing service (continual mobile phone access, SMS/email proficient etc).
• If for reasons as ascertained by 4Cyte, the patient cannot be safely dosed via the 4Cyte warfarin dosing service, then the patient will be discharged by 4Cyte, back into the care of the managing general practitioner.

Under the 4Cyte’s warfarin dosing service, each of the referring practitioner, the patient’s general practitioner, the patient, and if applicable, the nursing home, have continuing responsibilities and obligations. These are outlined below:

1. Referring Practitioner Obligations (often specialist / hospital):
1. Ensure that 4Cyte’s digital warfarin dosing service is suitable for this patient.
2. Ensure that the patient meets the strict requirements as outlined at here.
3. Educate the patient – explaining bleeding risk, monitoring expectations, ensure provision of patient warfarin booklet / record.
4. Define the plan at initiation / referral – completion of the online application form including indication, target INR range, intended duration, any special risks etc.
5. Communicate the plan and the stakeholders’ respective obligations to the patient, and to the patient’s nominated General Practitioner.


2. General Practitioner Obligations:
1. Clinical oversight and prescribing: confirming indication / target INR, prescriptions, and review risk / benefit at each visit.
2. Review each INR result, and dosing recommendation.
3. Ensure patient compliance with dosing and testing scheduling.
4. Ensure patient remains compliant with the enrolment conditions and importantly competent to be managed through a digital warfarin dosing service – competent in SMS and electronic only communication – SMS, Email, Webform.
5. Management of intercurrent issues – assess bleeding / thrombosis symptoms, manage drug / diet / illness changes, update care plan.
6. Management of patient.
7. Ensure patient complies with ongoing documentation of patient-held record – dose tracker etc.
8. Issue the patient with Rule 3 exempt pathology request forms for INR testing.
9. Co-ordinate monitoring and procedures – ensuring the patient attends for scheduled INRs, liaise with specialists and nurses and pre-operative management if needed.
10. Management of escalated INR results and adverse events.


3. 4Cyte dosing service Obligations:
1. Responsibility for dosing commences with acceptance by 4Cyte into the service upon receipt of and consideration by 4Cyte of the enrolment forms “Referring Practitioner’s Warfarin Dosing Application Form” + “Patient’s Warfarin Dosing Application Form” completed by both the Referring Practitioner and the Patient.
2. Responsibility for dosing only remains with 4Cyte as long as the patient continues to remain enrolled by 4Cyte. If 4Cyte discharges the patient from the dosing service, the responsibility for dosing will revert to the patient’s general practitioner.
3. Interpret each INR in context (recent doses etc) recommend next doses and next test date.
4. Communicate (by download) each INR, recommended dose and next test date to the referring general practitioner.
5. Escalate by fax any INR >4.0 to the patient’s general practitioner if fax number held on file.
6. Escalate by SMS any INR >4.9 to the patient’s general practitioner cascade mobile number if held on file.
7. Communicate (by download) each INR, dose and next test date to the nursing home where the patient is a resident of a RACF.


4. Nursing Home Obligations (for RACF patients only):
1. Keep a current, accurate medication chart that reflects the latest prescribed warfarin dose and target INR, with clear directions and prescriber identity.
2. Use charting practices suitable for variable-dose medicines; ensure dose changes are promptly transcribed and double-checked to minimise known error risks.
3. Standardise administration time so doses can be adjusted against day’s INR and to reduce after-hours errors.
4. Receive dose instructions and administer exactly as prescribed.
5. Before giving warfarin, screen for red flags (bleeding, missed doses, new meds, illness) and hold/escalate per protocol if safety concerns arise.
6. Ensure staff have access to resident information and education materials about warfarin (booklet/record).
7. Operate a recall / diary system for INRs and book 4Cyte collections for due date.
8. Clear and timely communication with the patient’s general practitioner in terms of dosing, triggers for escalation (eg bleeding, high INR, surgery, overdose etc).


5. Patient's Dosing Obligations:

For a complete outline of obligations see here

1. Adherence and Testing:
• take the exact dose at same time daily
• attend INR tests as scheduled
2. Report changes to their GP promptly:
• changes to diet / alcohol
• any illnesses
• planned leave or hospital procedures etc
• changes to medicine and herbal medicine regime
3. Know and be alert to:
• symptoms such as bleeding, bruising, black stools, headaches etc and seek urgent care

4Cyte’s warfarin dosing service is only suitable to optimise care for a subset of patients.

For patients residing in the community, to qualify for enrolment, the referring doctor and general practitioner MUST assess the patient as complying with each of the below criteria:

1. be taking warfarin
2. have direct and continual access to a personal mobile phone
3. be competent in digital-based communications, including:
• be able to electronically receive, comprehend and acknowledge SMS dosing instructions
• be able to follow English and SMS dose instructions
• be able to correspond proficiently via email, webforms etc
4. be a resident of Victoria, Far Northen NSW or Queensland
5. have a managing GP who routinely refers their patients to 4Cyte Pathology
6. have a managing GP who has provided their cascade and after hours contact details to 4Cyte Pathology
7. have a minimum enrolment period of one month
8. be able to attend for testing on scheduled dates
9. not have been discharged from any warfarin dosing service due to non-compliance
10. not require a narrow target range (less than one unit)
11. not require daily INR levels
12. not require acute care

For patients residing in aged care RACF, the referring doctor and general practitioner MUST assess the patient as complying with each of the below criteria:

1. be a resident of a RACF where the RACF acknowledges its obligations as outlined here
2. be taking warfarin
3. be a resident of Victoria, Far Northen NSW or Queensland
4. have a managing GP who routinely refers their patients to 4Cyte Pathology
5. have a managing GP who has provided their cascade and after hours contact details to 4Cyte Pathology
6. have a minimum enrolment period of one month
7. be able to attend for testing on scheduled dates
8. not have been discharged from any warfarin dosing service due to non-compliance
9. not require a narrow target range (less than one unit)
10. not require daily INR levels
11. not require acute care

If the patient does not meet all of the above criteria for enrolment, then care for this patient’s care cannot be optimised under the 4Cyte dosing service and the referring doctor / general practitioner must NOT apply to enrol the patient in the 4Cyte warfarin dosing service.

It is the patient and the patient’s general practitioner responsibility to make arrangements for warfarin dosing, INR testing and warfarin dosing when the patient is unable to attend a 4Cyte collection service as scheduled.

These circumstances include:

• Travel
• Vacations
• Hospital admission
• Perioperative

It is a requirement that upon discharge from hospital, the discharging specialist or the patient’s general practitioner submits the discharge form here. This enables 4Cyte to recommence dosing the patient with updated information on the care of the patient.

There are various circumstances when the patient’s general practitioner or the 4Cyte warfarin dosing service have the responsibility of withdrawing the patient from the 4Cyte warfarin dosing service. Upon withdrawal, responsibility for any dosing requirements henceforth will return to the patient’s general practitioner.

These circumstances include any clinical safety events:

• Bleeding event
• Urgent reversal/haemostatic support
• Very high/unstable INRs
• Serious intercurrent illness (e.g., acute hepatic failure, sepsis),
• Suspected overdose
• Inability to safely continue community dosing
• Transitioning off warfarin

These circumstances include any governance/operational events:

• Repeated non-attendance
• Refusal of testing
• Non-adherence to dosing instructions
• Failure of patient to confirm receipt and acknowledgement of SMS dose instructions

And any events / failure of the patient to adhere to the ongoing criteria for continued enrolment as outlined here.

To withdraw the patient from the program and notify the relevant parties, the following form must be completed here.

To review the terms and conditions and FAQs as provided by the 4Cyte warfarin dosing service to the patient click here.