What the FDA labels say about taking them together
Cyclobenzaprine and sufentanil
Sufentanil's FDA label of June 1, 2026 names cyclobenzaprine in its drug interactions section; the cyclobenzaprine labels PlainMeds reads (3) do not name sufentanil. The sufentanil label: “The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.”
Check it at the source: the cyclobenzaprine FDA label on DailyMed (effective February 21, 2025, Jubilant Cadista Pharmaceuticals Inc.); the sufentanil FDA label on DailyMed (effective June 1, 2026, Hospira, Inc.).
What does the cyclobenzaprine label say about sufentanil?
Cyclobenzaprine's label (effective February 21, 2025) and its 2 other brand-application labels do not name sufentanil in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Cyclobenzaprine Hydrochloride), Jubilant Cadista Pharmaceuticals Inc., effective February 21, 2025 (SPL set 592871f6-0eb2-4624-9e10-bd8bf767c002), via openFDA; the full label on DailyMed
What does the sufentanil label say about cyclobenzaprine?
Sufentanil label, drug interactionsSerotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. … serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
Sufentanil label, warnings and precautionsSerotonergic 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, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), and drugs that impair metabolism of serotonin (including MAO inhibitors, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue) [see Drug Interactions (7) ].
Source: FDA drug label (Sufentanil Citrate), Hospira, Inc., effective June 1, 2026 (SPL set 20293943-46ff-4345-1aa4-929b4e017a25), 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
| Cyclobenzaprine | Sufentanil | |
|---|---|---|
| Labeled for | Muscle spasms and spasticity, Nerve pain and fibromyalgia | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0171 per tablet 10 mg tablet | n/a |
| Shortage now | No current entry | In shortage |
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