What should be done if a patient taking atorvastatin (a statin) for hyperlipidemia is mistakenly given warfarin (an anticoagulant)?

Inform the Patient Directly of the Medication Error

You must personally inform the patient of the medication error and explain its potential complications immediately. This is both an ethical obligation and a standard of care requirement in modern medical practice.

Ethical and Legal Obligations

• Direct physician-to-patient disclosure is the standard of care for medication errors, regardless of whether harm occurred 1, 2, 3
• The patient is alert and fully oriented, making them the appropriate recipient of this information—not family members or intermediaries
• Delegating disclosure to risk management is inappropriate; the treating physician bears primary responsibility for transparent communication with their patient

Why Each Alternative is Incorrect

• Option A is ethically and legally indefensible: The absence of immediate harm does not eliminate the disclosure obligation. A single 5 mg dose of warfarin in a patient not previously on anticoagulation creates potential bleeding risk, particularly given the rhabdomyolysis context where renal function may be compromised
• Option B inappropriately delegates responsibility: While risk management should be notified, they should not be the primary communicators. The physician-patient relationship requires direct disclosure
• Option C violates patient autonomy: Informing a relative instead of the competent, alert patient bypasses the patient's right to their own medical information

Clinical Considerations for This Specific Error

• A single 5 mg warfarin dose in a warfarin-naïve patient typically produces minimal anticoagulation effect, with INR elevation usually appearing 24-48 hours post-dose and peaking at 36-72 hours 4
• The actual bleeding risk from this single dose is low but not zero, particularly if the patient has compromised renal function from rhabdomyolysis, which could affect warfarin metabolism 1, 3
• Atorvastatin and warfarin do not have a clinically significant interaction—atorvastatin does not alter warfarin's anticoagulant activity 5—so the substitution itself doesn't create a dangerous drug interaction

Recommended Disclosure Approach

• Inform the patient promptly and directly about what happened: "You were mistakenly given warfarin, a blood thinner, instead of your cholesterol medication atorvastatin"
• Explain potential complications: "Warfarin can increase bleeding risk. From a single dose, this risk is small but we need to monitor you"
• Express appropriate regret without excessive self-flagellation: "I regret this error occurred and we are taking steps to prevent it from happening again"
• Outline the monitoring plan: Check INR at 24 and 48 hours post-dose; observe for any signs of bleeding (bruising, blood in urine/stool, unusual bleeding from any site) 1, 3

Follow-Up Actions

• Document the error, disclosure, and monitoring plan thoroughly in the medical record
• Notify risk management and pharmacy for system-level review and prevention strategies
• No reversal with vitamin K is needed for a single 5 mg dose in the absence of bleeding or elevated INR 1, 3
• Continue the patient's atorvastatin as prescribed for the hyperlipidemia