Citalopram and Phentermine and topiramate interaction
Citalopram and Phentermine and topiramate: the Citalopram prescribing label flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Citalopram label · effective 2025-10-07
Avoid use of Citalopram Capsules in CYP2C19 poor metabolizers, patients receiving concomitant cimetidine or another CYP2C19 inhibitor, patients with hepatic impairment, and patients who are greater than 60 years of age, because Citalopram Capsules are only available in a 30 mg dose strength and dosage adjustments are not possible [see Drug Interactions ( 7 ),…
CYP2C19 inhibitors and CYP2C19 poor metabolizers: Avoid concomitant use.
Intervention: Avoid concomitant use of Citalopram Capsules with CYP2C19 inhibitors [see Warnings and Precautions ( 5.2 )].
The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St.
CYP2C19 Inhibitors Clinical Impact: Concomitant use of citalopram with CYP2C19 inhibitors increases the risk of QT prolongation and/or ventricular arrhythmias compared to the use of citalopram alone [see Clinical Pharmacology ( 12.3 )].
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.