Record ID: MS-N074 · Family: Food–drug interaction / oral cancer therapy · Clinical question: Can grapefruit change exposure to oral anticancer medicines?

Evidence label: Confirmed pharmacokinetic interactions for several drugs, but direction and size are drug-specific; clinical outcome effects are usually unknown.

Evidence at a glance

• Benefit: Grapefruit is not a strategy to improve cancer treatment.
• Certainty: Moderate that interactions occur for selected CYP3A/P-glycoprotein substrates; low for most clinical outcome consequences.
• Risk: Exposure may rise or fall depending on the drug, dose, timing and intestinal transport/metabolism.
• Cancer control: Drug concentrations were studied; tumor response and survival generally were not.

What was studied

In a randomized crossover pilot, six patients received etoposide 50 mg intravenously, etoposide 50 mg orally, and oral etoposide after 100 mL grapefruit juice. Other small studies tested nilotinib or sunitinib with grapefruit juice, including healthy volunteers.

These are pharmacokinetic studies. A grapefruit interaction with one drug cannot be assumed for every oral anticancer medicine.

What the results show

With oral etoposide, grapefruit juice reduced area under the concentration–time curve by 26.2%; median oral bioavailability was 52.4% with grapefruit versus 73.2% without, with large variability.

By contrast, 240 mL grapefruit juice increased nilotinib exposure in healthy volunteers (AUC about 29% and peak concentration about 60%), while the sunitinib change was described as marginal. These opposite directions illustrate why a generic “grapefruit effect” is unsafe.

Important limits

• Studies were small and often used one juice volume and one product batch.
• Several involved healthy volunteers rather than people with cancer.
• Pharmacokinetic changes do not automatically establish toxicity, loss of efficacy or a need for dose adjustment.
• The prescribing information for the exact drug takes priority; funding and conflicts were not re-extracted for this record.

Safety and practical context

Until an oncology pharmacist checks the exact drug, avoid grapefruit and related products named in the medicine’s label. Seville oranges, pomelos and tangelos can share relevant compounds, but advice varies. Do not compensate by changing the anticancer dose.

Questions for the care team

• Does the current drug label prohibit grapefruit or related citrus?
• How much and how often is the fruit or juice consumed?
• Is the medicine also affected by acid-suppressing drugs, food timing or herbal CYP3A modifiers?

Sources checked

• Reif et al., randomized crossover etoposide pilot, 2002 (PMID 12389073).
• NCI PDQ: Cancer Therapy Interactions With Foods and Dietary Supplements — health-professional summary.
• Nilotinib–grapefruit pharmacokinetic study (PMID 19948946).
• Sunitinib–grapefruit pharmacokinetic study (PMID 20512335).

Last literature search: October 19, 2026 · Record appraisal: October 19, 2026

Educational information only. This record is not a prescription and does not replace advice from the oncology team or oncology pharmacist.