Summary
Only the single claim explicitly framed as a bleeding-risk warning is supported by the provided prescribing information. The remaining listed food/supplement interaction claims are not supported by the provided label excerpts.
Category Scores
Accurate Statements
Warfarin sodium can cause major or fatal bleeding (WARNING: Bleeding Risk).
Boxed Warning / “Bleeding Risk” and Warnings and Precautions (5.1): “Warfarin sodium can cause major or fatal bleeding.”
Regular INR monitoring is part of minimizing bleeding risk.
Boxed Warning / “Bleeding Risk”: “Perform regular monitoring of INR in all treated patients…” and Warnings and Precautions (5.1): “Perform regular monitoring of INR in all treated patients.”
Patients should be instructed to report signs/symptoms of bleeding.
Boxed Warning / “Bleeding Risk” and 17 Patient Counseling Information: “Instruct patients… and to report signs and symptoms of bleeding.”
Unsupported Statements
Foods rich in vitamin K can counteract the effects of warfarin, leading to reduced efficacy.
The provided label excerpt supports that dietary vitamin K affects INR and advises maintaining a consistent amount of vitamin K, but it does not state that vitamin K-rich foods counteract warfarin to reduce efficacy.
Leafy greens like spinach, broccoli, kale, and collard greens are high in vitamin K and should be limited or avoided with warfarin.
The provided label excerpt does not list these specific foods or recommend limiting/avoiding them.
Cabbage, Brussels sprouts, and cauliflower should be limited or avoided with warfarin due to their vitamin K content.
The provided label excerpt does not list these specific foods or recommend limiting/avoiding them.
Fermented foods like sauerkraut, kimchi, and natto should be limited or avoided with warfarin due to their vitamin K content.
The provided label excerpt does not list these foods or provide a vitamin K-based limitation/avoidance recommendation for them.
Green tea and green coffee should be limited or avoided with warfarin.
No green tea/green coffee interaction or limitation is present in the provided label excerpts.
Vitamin K-fortified foods, such as soy milk and cereals, should be limited or avoided with warfarin.
No specific guidance about soy milk or cereals being limited/avoided appears in the provided label excerpts.
Cranberries and cranberry juice may increase the risk of bleeding with warfarin.
The provided label excerpt does not mention cranberries/cranberry juice.
Grapefruit and grapefruit juice may interact with warfarin and increase bleeding risk.
The provided label excerpt does not mention grapefruit/grapefruit juice.
Raw onions and garlic may increase the risk of bleeding with warfarin.
The provided label excerpt only states that some botanicals may have anticoagulant/antiplatelet/fibrinolytic properties and gives examples (garlic and Ginkgo biloba) but does not support “raw onions” and does not specifically frame garlic as a definitive bleeding-risk increase in the way stated.
High-fat foods may slow the absorption of warfarin.
The provided label excerpts do not mention high-fat foods affecting warfarin absorption.
Red wine may cause stomach ulcers and interact with warfarin.
The provided label excerpt does not mention red wine or ulcer risk.
Unripe or uncooked foods may be high in vitamin K or other compounds that interact with warfarin.
The provided label excerpts do not support this generalized claim.
Warfarin's patent has expired.
The provided prescribing information excerpts contain no patent status information.
Generic and biosimilar versions of warfarin have entered the market due to patent expiry.
The provided prescribing information excerpts contain no patent/generic/biosimilar market-entry statements.
Contradictions
Low
AI Statement
Leafy greens and other vitamin K-containing foods should be limited or avoided with warfarin.
Label Reference
Warnings and Precautions (5.1) / Drug Interactions (7.5): “Patients should avoid drastic changes in dietary habits; eat a normal, balanced diet maintaining a consistent amount of vitamin K.”
Important Omissions
No statement that the label advises maintaining a consistent amount of vitamin K and avoiding drastic dietary changes (while recognizing that dietary vitamin K affects INR).
Importance:
Moderate
Safety Assessment
Potential Patient Risk:
Moderate
Unsupported/overly specific food and supplement avoidance claims could lead to inappropriate dietary restriction. The label instead emphasizes consistent vitamin K intake and regular INR monitoring.
Regulatory Assessment
| On Label |
No |
| Off-label Discussion |
No |
| Promotes Unapproved Use |
No |
| Hallucination Risk |
High |
Recommendation
Needs Revision
Primary Issue
Most listed interaction/avoidance assertions (specific foods/drinks/supplements and patent/market claims) are not supported by the provided FDA label excerpts, and several conflict with the label’s instruction to maintain consistent vitamin K intake rather than avoid specific vitamin K-containing foods.
Suggested Improvement
Limit claims to what the provided label supports: warfarin’s boxed bleeding risk, need for regular INR monitoring, patient reporting of bleeding, and dietary guidance to avoid drastic changes and maintain consistent vitamin K intake; avoid listing specific foods/drinks/supplements unless the label excerpts explicitly mention them.