Availability of Warfarin

Further to DrugAlert volume 858, HPS Pharmacies wish to advise that Viatris is continuing to experience a supply interruption for Coumadin^® tablets as follows:

Coumadin^® Tablets
Warfarin sodium 5mg
ARTG 42279

Normal supplies of Coumadin^® 5mg tablets are expected to resume by end-July 2023.

The supply of other strengths of warfarin tablets has improved, although some strengths of Coumadin^® and Marevan^® tablets are experiencing a short-term supply interruption.

The Therapeutic Goods Administration (TGA) has made a Serious Scarcity Substitution Instrument (SSSI) to help manage this situation. The SSSI allows pharmacists to substitute a lower strength Coumadin^® tablet if the 5mg tablet is unavailable.

This SSSI is in force until 7 August 2023 unless revoked earlier by the TGA. Points to consider include:

• Either Coumadin^® 1mg tablet OR Coumadin^® 2mg tablet can be offered as a substitute. A combination of 1mg and 2mg tablets cannot be dispensed as a substitute for Coumadin^® 5mg tablets;
• The patient should receive sufficient substitutable medicine to ensure an equivalent dosage regimen and duration to that prescribed for Coumadin^® 5mg tablets. Information on Pharmaceutical Benefits Scheme (PBS) subsidy arrangements can be found on the PBS website;
• The SSSI may not be used to substitute medicines if the prescriber has indicated on the prescription that substitution is not permitted;
• The patient, or the person acting on their behalf, must consent to the substitution;
• The patient, or person acting on their behalf, must be advised of the number of tablets that must be taken to be equivalent to the prescribed dose; and
• If the tablet requires splitting, appropriate instructions must be provided to obtain the correct dose of substitutable medicine.

Warfarin is a high-risk medication. The patient’s health literacy and capacity to understand this substitution must be carefully assessed. If a patient is considered unsuitable to receive the substitutable medicine, the sponsor (Viatris) should be contacted to enquire about emergency stock of Coumadin^® 5mg tablets.

Retain this notice in a prominent position, including in other related business units until supplies return to normal. Report any problems identified with medicines, vaccines or medical devices to the TGA.

Should you require further information regarding this matter, please contact Viatris on 1800 314 527 or your pharmacist at HPS Pharmacies.

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