What the FDA labels say about taking them together
Fentanyl and nortriptyline
Nortriptyline's FDA label of December 4, 2024 names fentanyl in its warnings section; fentanyl's label does not name nortriptyline itself but warns about its class (Tricyclic antidepressants). The nortriptyline label: “Serotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and SSRIs, including Pamelor, alone but particularly with concomitant use of other serotonergic drugs …”
Check it at the source: the fentanyl FDA label on DailyMed (effective March 6, 2026, Hikma Pharmaceuticals USA Inc.); the nortriptyline FDA label on DailyMed (effective December 4, 2024).
What does the fentanyl label say about nortriptyline?
Fentanyl's label does not name nortriptyline itself; it warns about its class (Tricyclic antidepressants):
Fentanyl label, warnings and precautionsIf a patient is suspected to be experiencing OIH, carefully consider appropriately decreasing the dose of the current opioid analgesic or opioid rotation (safely switching the patient to a different opioid moiety) [see Dosage and Administration (2), Warnings and Precautions (5.7) ] . 5.8 Serotonin Syndrome with Concomitant Use of Serotonergic Drugs Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of fentanyl with serotonergic drugs. …
Fentanyl label, warnings and precautionsSyndrome with Concomitant Use of Serotonergic Drugs Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of fentanyl with serotonergic drugs. Serotonergic drugs include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonergic neurotransmitter system (e.g., mirtazapine, trazadone, tramadol), certain …
Source: FDA drug label (Fentanyl Citrate), Hikma Pharmaceuticals USA Inc., effective March 6, 2026 (SPL set ce5db1c2-feb1-4ad2-847a-d02e865bd47e), via openFDA; the full label on DailyMed
What does the nortriptyline label say about fentanyl?
Nortriptyline label, warningsSerotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and SSRIs, including Pamelor, alone but particularly with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, and St. John’s Wort) and with drugs that impair metabolism of serotonin (in particular, MAOIs, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
Source: FDA drug label (PAMELOR), SpecGx LLC, effective December 4, 2024 (SPL set e17dc299-f52d-414d-ab6e-e809bd6f8acb), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Fentanyl | Nortriptyline | |
|---|---|---|
| Labeled for | Pain | Depression |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $1.79 per mL 100 mcg/2 mL vial | $0.113 per capsule 10 mg capsule |
| Shortage now | In shortage | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once