If a patient on warfarin reports that a batch of tablets has changed color from brown to blue and notes bruising, what is the safest course of action?

If a patient on warfarin reports that a batch of tablets has changed color from brown to blue and notes bruising, what is the safest course of action?

• A. Continue with current tablets
• B. Switch to brown tablets
• C. Seek advice from a pharmacist by phone
• D. Refer to A&E urgently

Answer: (D)

Warfarin has a narrow therapeutic window, so any signs that a tablet might be tainted or a patient’s bleeding risk is increasing must be treated as an urgent safety issue. A change in the color of the tablets from brown to blue could indicate a different or counterfeit batch, and bruising suggests that the anticoagulant effect may be stronger than intended or that there is active bleeding. Taken together, these signs require immediate clinical assessment rather than routine management. The safest course is urgent evaluation in A&E so clinicians can check the patient’s coagulation status (INR), inspect the medication batch, verify the correct product, and determine whether any action is needed to protect the patient (such as stopping the medication temporarily and adjusting therapy). In the meantime, the patient should avoid taking more of the tablets and bring the packaging and remaining tablets to the hospital to aid verification.

Warfarin has a narrow therapeutic window, so any signs that a tablet might be tainted or a patient’s bleeding risk is increasing must be treated as an urgent safety issue. A change in the color of the tablets from brown to blue could indicate a different or counterfeit batch, and bruising suggests that the anticoagulant effect may be stronger than intended or that there is active bleeding. Taken together, these signs require immediate clinical assessment rather than routine management. The safest course is urgent evaluation in A&E so clinicians can check the patient’s coagulation status (INR), inspect the medication batch, verify the correct product, and determine whether any action is needed to protect the patient (such as stopping the medication temporarily and adjusting therapy). In the meantime, the patient should avoid taking more of the tablets and bring the packaging and remaining tablets to the hospital to aid verification.