Partial
Partially Aligned
Patient Risk:
Medium
Summary
Several grapefruit/CYP3A4 interaction and increased plasma atorvastatin/extra risk statements are supported, but multiple parts (notably: grapefruit constituent identification/enzymatic inhibition mechanism details and quantitative 40% increase and study assertions) are not supported by the provided FDA label excerpts.
Category Scores
Accurate Statements
Lipitor (atorvastatin) is used in adult patients without clinically evident coronary heart disease but with multiple risk factors for coronary heart disease to reduce risk of myocardial infarction, stroke, and reduce risk for revascularization procedures and angina.
Indications and Usage 1.1 Prevention of Cardiovascular Disease (adult patients with multiple risk factors reduce MI, stroke, revascularization procedures/angina).
Lipitor is metabolized by cytochrome P450 3A4.
Drug Interactions 7.1 Strong Inhibitors of CYP 3A4: "LIPITOR is metabolized by cytochrome P450 3A4."
Grapefruit juice contains components that inhibit CYP3A4 and can increase plasma concentrations of atorvastatin.
Drug Interactions 7.2 Grapefruit Juice: "Contains one or more components that inhibit CYP 3A4 and can increase plasma concentrations of atorvastatin..."
Elevated atorvastatin exposure from grapefruit juice may increase risk of muscle damage/rhabdomyolysis.
Warnings and Precautions 5.1 Skeletal Muscle (myopathy/rhabdomyolysis risk increased with higher doses and strong CYP3A4 inhibitors); Drug Interactions 7.2 (grapefruit can increase plasma concentrations).
Grapefruit juice may interact with other CYP3A4-metabolized drugs/strong CYP3A4 inhibitors, potentially increasing atorvastatin plasma concentrations.
Drug Interactions 7 (risk of myopathy increased with strong CYP3A4 inhibitors); 7.1 (increases plasma concentrations with strong CYP3A4 inhibitors); 7.2 (grapefruit components inhibit CYP3A4 and increase plasma concentrations).
FDA label includes that rare rhabdomyolysis has been reported with Lipitor and that risk increases with concomitant use of strong CYP3A4 inhibitors (and with higher doses).
Warnings and Precautions 5.1 Skeletal Muscle (rhabdomyolysis; increased risk with certain drugs such as cyclosporine and strong CYP3A4 inhibitors; "Atorvastatin... The concomitant use of higher doses... with certain drugs... strong CYP3A4 inhibitors... increases the risk of myopathy/rhabdomyolysis").
Unsupported Statements
Lipitor (atorvastatin) is a statin that works by inhibiting cholesterol production in the liver.
The provided label excerpt describes inhibition of HMG-CoA reductase (mechanism), but does not explicitly state "inhibiting cholesterol production in the liver" or "in the liver" in the included text.
Grapefruit juice contains furanocoumarins, specifically bergamottin and dihydroxybergamottin.
The provided label excerpt (7.2 Grapefruit Juice) does not name furanocoumarins or those specific compounds.
Bergamottin and dihydroxybergamottin in grapefruit juice inhibit the activity of the CYP3A4 enzyme.
The provided label excerpt does not identify these compounds or link them specifically to CYP3A4 inhibition.
CYP3A4 is responsible for metabolizing many medications, including Lipitor (atorvastatin).
The excerpt supports that Lipitor is metabolized by CYP3A4, but does not support the broader statement about CYP3A4 metabolizing many medications.
Consuming grapefruit juice can increase levels of Lipitor (atorvastatin) in the bloodstream.
The label excerpt supports increased plasma concentrations with grapefruit, but the claim wording "in the bloodstream" is not directly stated (label uses "plasma concentrations").
Grapefruit juice may increase the risk of liver damage, particularly in individuals with pre-existing liver conditions.
While the label includes liver dysfunction warnings/contraindications, the provided grapefruit-specific interaction excerpt does not mention liver damage risk or pre-existing liver conditions.
A study reported that consuming grapefruit juice with Lipitor increased atorvastatin levels in the bloodstream by 40%.
No quantitative 40% increase is provided in the supplied excerpts.
A study reported that grapefruit juice reduced the metabolism of Lipitor, leading to increased levels of the medication in the bloodstream.
The supplied excerpts indicate CYP3A4 inhibition and increased plasma concentrations, but do not provide a study statement about "reduced metabolism" or any metabolism-specific study conclusion.
The FDA has warned that consuming grapefruit or grapefruit juice with atorvastatin may increase the risk of muscle damage and liver damage.
Label excerpt explicitly addresses muscle/myopathy risk via increased plasma concentrations with CYP3A4 inhibition; however, liver damage risk specifically tied to grapefruit is not stated in the provided excerpts.
Contradictions
Important Omissions
No mention of the label’s specific caution threshold for grapefruit consumption (>1.2 liters per day).
Importance:
Minor
Safety Assessment
Potential Patient Risk:
Medium
Most grapefruit/CYP3A4 interaction claims are consistent with the label excerpt, but unsupported quantitative and liver-damage-specific statements (and compound-identification/mechanism details not supported) could mislead risk expectations.
Regulatory Assessment
| On Label |
No |
| Off-label Discussion |
No |
| Promotes Unapproved Use |
No |
| Hallucination Risk |
Medium |
Recommendation
Partially Aligned
Primary Issue
Several claims are not supported by the provided label excerpts, including grapefruit constituent identification (bergamottin/dihydroxybergamottin), quantitative "40%" increase, grapefruit-related liver damage risk, and a specific "FDA warned" liver-damage statement tied to grapefruit.
Suggested Improvement
Restrict grapefruit interaction statements to what the label excerpt supports (grapefruit inhibits CYP3A4 and can increase atorvastatin plasma concentrations, especially with excessive intake >1.2 L/day) and remove or qualify unsupported compound-identification, numerical claims, and grapefruit-specific liver-damage assertions not present in the provided excerpts.