Poor
Not Aligned
Patient Risk:
Moderate
Summary
Only the grapefruit juice interaction is supported by the provided FDA label (7.2). Many mechanistic and extension claims (furanocoumarins, CYP3A4 gut inhibition, atorvastatin side effects causality, and non-grapefruit citrus/quantity attenuation) are not supported by the supplied label text, resulting in substantial misalignment.
Category Scores
Accurate Statements
The interaction is most pronounced with grapefruit.
Supported in spirit by 7.2 (grapefruit juice components inhibit CYP3A4 and can increase atorvastatin concentrations), and consistent with the label's focus on grapefruit juice as the relevant citrus interaction.
Increased side effects can include muscle weakness.
Consistent with 5.1 where myopathy is described as muscle aches or muscle weakness.
Increased side effects can include kidney problems.
Consistent with 5.1 describing rhabdomyolysis with acute renal failure secondary to myoglobinuria.
Unsupported Statements
Grapefruit juice contains furanocoumarins.
Not supported by the provided label text; 7.2 states grapefruit juice contains components that inhibit CYP3A4 but does not mention furanocoumarins.
Furanocoumarins inhibit the enzyme CYP3A4 in the gut wall.
Mechanism and location (gut wall) are not stated in the provided label excerpts.
CYP3A4 is responsible for breaking down various medications, including Lipitor, in the liver.
The provided excerpts do not support this broad statement about CYP3A4 'breaking down various medications' or explicitly 'in the liver' for that claim.
CYP3A4 is the primary enzyme responsible for metabolizing atorvastatin, the active ingredient in Lipitor.
The provided label excerpt (12.3) suggests importance of CYP3A4 metabolism, but the label support provided does not establish CYP3A4 as 'primary' using the exact strength/wording.
Inhibition of CYP3A4 by furanocoumarins in grapefruit juice allows for higher levels of atorvastatin to build up in the body.
7.2 supports increased plasma concentrations with grapefruit juice, but the specific mechanistic chain using furanocoumarins is not supported by the provided excerpts.
Increased atorvastatin levels can lead to increased side effects.
Causal relationship between increased atorvastatin levels and 'side effects' is not explicitly stated in the provided label excerpts.
Increased side effects can include potentially life-threatening interactions with other medications.
The provided label excerpts discuss myopathy/rhabdomyolysis risk with certain drugs, but do not support the specific statement about 'life-threatening interactions with other medications' in the manner claimed, nor is any boxed warning cited.
Other citrus juices, like orange and tangerine, may contain smaller amounts of furanocoumarins.
Not supported by the provided label excerpts; 7.2 addresses grapefruit juice specifically and does not mention oranges/tangerines or furanocoumarins.
Furanocoumarins in citrus juice could inhibit CYP3A4.
Not supported by provided label text.
The interaction is thought to occur when furanocoumarins in citrus juice are ingested alongside Lipitor.
Uncited mechanistic detail not present in provided label excerpts.
The interaction is to a lesser extent seen with other citrus fruits like oranges and tangerines.
Not supported by the provided label excerpts.
The interaction may be less significant when consuming moderate amounts of these fruits.
The provided label text specifies thresholds for grapefruit juice consumption (>1.2 liters/day) but does not support 'moderate amounts' for oranges/tangerines or generalization beyond grapefruit.
The interaction may be less significant when consuming these fruits without Lipitor.
Not stated as a labeled guidance statement in the provided excerpts; also relies on an unsupported generalization beyond grapefruit.
Contradictions
Important Omissions
Grapefruit juice interaction is tied to 'excessive grapefruit juice consumption (>1.2 liters per day)' per 7.2, but the response does not include this labeled quantity threshold.
Importance:
Moderate
No explicit label framing that grapefruit juice can increase plasma concentrations of atorvastatin (7.2) without adding unsupported mechanistic details (e.g., furanocoumarins).
Importance:
Moderate
Safety Assessment
Potential Patient Risk:
Moderate
Unlabeled mechanistic/extension claims may cause patients to incorrectly generalize grapefruit juice interaction risk to other citrus (orange/tangerine) and to rely on unlabelled 'moderate amount' reassurances, while omitting the label's excessive grapefruit juice threshold (>1.2 L/day).
Regulatory Assessment
| On Label |
No |
| Off-label Discussion |
No |
| Promotes Unapproved Use |
No |
| Hallucination Risk |
High |
Recommendation
Not Aligned
Primary Issue
Mechanistic and scope expansions beyond grapefruit juice (furanocoumarins; CYP3A4 gut-wall inhibition; oranges/tangerines; dose attenuation) are not supported by the provided label excerpts, and the label's grapefruit juice excess threshold is omitted.
Suggested Improvement
Restrict interaction discussion to what the provided label supports: grapefruit juice (7.2) increases plasma concentrations of atorvastatin, especially with excessive consumption (>1.2 liters/day). Avoid stating furanocoumarins/CYP3A4-gut mechanisms and avoid claiming interactions for oranges/tangerines or 'moderate amounts' unless supported by the full label text.