Selective serotonin reuptake inhibitor (SSRI)
Citalopram and grapefruit: a real interaction?
Grapefruit is famous as the juice that interacts with medications, and the warning is real for a number of drugs. Whether it matters specifically for Citalopram (Citalopram) at 10mg, 20mg, 40mg depends on whether the active ingredient Citalopram is metabolised by CYP3A4 in the gut wall and how much that pathway contributes to first-pass metabolism.
The CYP3A4 mechanism
Grapefruit (and its juice) inhibits CYP3A4 enzymes in the gut wall, increasing the absorbed dose of medications metabolised by that enzyme. For drugs in the Selective serotonin reuptake inhibitor (SSRI) class that go through CYP3A4 first-pass metabolism, regular grapefruit consumption can raise plasma levels of Citalopram by a clinically meaningful margin and amplify side effects.
What to do with Citalopram
According to the prescribing information for Citalopram, if grapefruit is flagged as an interaction, the safest practice is to avoid grapefruit entirely or to discuss timing with the prescriber. Citalopram selectively inhibits the serotonin reuptake transporter, increasing synaptic serotonin availability with limited affinity for noradrenaline transporters or other receptors. A small occasional serving may be tolerable; daily large servings around the time of Citalopram dosing are not recommended at 10mg, 20mg, 40mg.
Frequently asked questions
Can I eat grapefruit while on Citalopram? ▾
For some Selective serotonin reuptake inhibitor (SSRI) medications, grapefruit is best avoided or limited because of CYP3A4 inhibition. Whether Citalopram specifically is affected depends on Citalopram; the prescribing information lists this. When in doubt, ask the pharmacist or check the patient leaflet.
How much grapefruit is too much with Citalopram? ▾
For drugs where the interaction matters, even modest daily grapefruit intake (one whole grapefruit or one large glass of juice) can shift drug levels noticeably. For Citalopram at 10mg, 20mg, 40mg, individual tolerance varies; the cautious choice is to avoid grapefruit if any interaction is mentioned.
Products containing Citalopram
More on Citalopram
- With alcoholCitalopram and alcohol — is it safe to drink?
- With foodShould Citalopram be taken with food?
- Side effectsCitalopram side effects: common, rare and warning signs
- Dosage guideCitalopram dosage guide: how much to take and when
- OnsetHow fast does Citalopram start working?
- DurationHow long does Citalopram last?
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