Duloxetine and Palonosetron interaction
Duloxetine and Palonosetron: both prescribing labels 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 Duloxetine label · effective 2026-03-02
Serotonin Syndrome: Increased risk when co-administered with other serotonergic agents but also when taken alone.
If concomitant use of Duloxetine Delayed-Release Capsules with other serotonergic drugs is clinically warranted, inform patients of the increased risk for serotonin syndrome and monitor for symptoms.
Other Serotonergic Drugs Prevention or Management Monitor for symptoms of serotonin syndrome when Duloxetine Delayed-Release Capsules is used concomitantly with other drugs that may affect the serotonergic neurotransmitter systems.
Mechanism and Clinical Effect(s) Concomitant use of Duloxetine Delayed-Release Capsules with other serotonergic drugs increases the risk of serotonin syndrome.
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.
From the Palonosetron (posfrea) label · effective 2025-04-29
Serotonin syndrome : reported with 5-HT 3 receptor antagonists alone, but particularly with concomitant use of serotonergic drugs.
Patients should be monitored for the emergence of serotonin syndrome, especially with concomitant use of POSFREA and other serotonergic drugs.
Patients should be informed of the increased risk of serotonin syndrome, especially if POSFREA is used concomitantly with other serotonergic drugs [see Drug Interactions (7.1) ] .
Serotonergic Drugs: Monitor for serotonin syndrome; if symptoms occur, discontinue POSFREA and initiate supportive treatment ( 7.1 )
Serotonergic Drugs Serotonin syndrome (including altered mental status, autonomic instability, and neuromuscular symptoms) has been described following the concomitant use of 5-HT 3 receptor antagonists and other serotonergic drugs, including selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs).
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.