Food and medicine interaction
Grapefruit and grapefruit juice and buspirone (BuSpar), an anti-anxiety medicine
EstablishedEvidence level: established. Shown in drug labeling or in controlled studies in people.
Last reviewed
What can happen
Grapefruit juice can sharply raise the amount of buspirone in the blood. In a controlled study in 10 healthy volunteers, double-strength grapefruit juice raised average peak buspirone levels 4.3-fold and total exposure 9.2-fold; that may mean more side effects such as dizziness or fatigue.
- Why it happens
- Grapefruit blocks CYP3A4 in the gut wall, the enzyme that normally breaks down most of a buspirone dose before it reaches the blood.
- At ordinary food amounts
- MedlinePlus advises avoiding large amounts of grapefruit juice and large amounts of grapefruit with buspirone. The study used large amounts of strong juice, so an occasional small serving is a question for your pharmacist, not a rule.
What to do
Ask your pharmacist or prescriber how much grapefruit, if any, is safe with your buspirone dose. Do not stop buspirone or change how you take it without talking to your prescriber first.
Never stop or change a prescribed medicine without talking to the prescriber.
Common questions
Can I have grapefruit and grapefruit juice while taking anti-anxiety medicines?
Ask your pharmacist or prescriber how much grapefruit, if any, is safe with your buspirone dose. Do not stop buspirone or change how you take it without talking to your prescriber first. MedlinePlus advises avoiding large amounts of grapefruit juice and large amounts of grapefruit with buspirone. The study used large amounts of strong juice, so an occasional small serving is a question for your pharmacist, not a rule.
Sources
- U.S. Food and Drug Administration. Grapefruit Juice and Some Drugs Don't Mix (consumer update).
- MedlinePlus (U.S. National Library of Medicine). Buspirone: drug information.
- Lilja JJ, et al. Grapefruit juice substantially increases plasma concentrations of buspirone. Clin Pharmacol Ther. 1998. PMID 9871430.
Related
- RemedyGrapefruit: the full evidence pageA healthy fruit with one serious catch: it changes how the body handles certain medicines. It is the best-documented food-drug interaction there is. The fat-burning claims are not supported.
- Interaction · EstablishedGrapefruit and grapefruit juice and some statins, such as simvastatin (Zocor) and atorvastatin (Lipitor)
- Interaction · EstablishedGrapefruit and grapefruit juice and some calcium channel blockers for blood pressure, such as felodipine and nifedipine
- Interaction · EstablishedGrapefruit and grapefruit juice and cyclosporine (Neoral, Sandimmune) and tacrolimus (Prograf)
- Interaction · EstablishedGrapefruit and grapefruit juice and oral budesonide (Entocort EC, Uceris) for Crohn's disease or ulcerative colitis
- Interaction · EstablishedGrapefruit juice and amiodarone (Pacerone, Cordarone), a heart rhythm medicine
- Interaction · EstablishedOrange, apple and grapefruit juice and fexofenadine (Allegra), an allergy medicine