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What the FDA labels say about taking them together

Fluvoxamine and methadone

Fluvoxamine's FDA label of June 27, 2026 names methadone in its warnings and precautions section, and methadone's label names fluvoxamine too. The methadone label: “Methadone undergoes hepatic N-demethylation by several cytochrome P450 (CYP) isoforms, including CYP3A4, CYP2B6, CYP2C19, CYP2C9, and CYP2D6. …”

Check it at the source: the fluvoxamine FDA label on DailyMed (effective June 27, 2026, Zydus Pharmaceuticals USA Inc.); the methadone FDA label on DailyMed (effective December 8, 2025, Epic Pharma, LLC).

What does the fluvoxamine label say about methadone?

Fluvoxamine label, warnings and precautions

The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and SSRIs, including fluvoxamine maleate extended-release capsules, alone but particularly with concomitant use of serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, meperidine, methadone, lithium, tramadol, tryptophan, buspirone, amphetamines 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).

Fluvoxamine Maleate label (ANI Pharmaceuticals, Inc., August 4, 2025), warnings and precautions

The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, meperidine, methadone, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. John's Wort) and with drugs that impair metabolism of serotonin, i.e., MAOIs [see Contraindications ( 4 ), Drug Interactions ( 7.1 )].

Source: FDA drug label (Fluvoxamine Maleate, NDA021519), ANI Pharmaceuticals, Inc., effective August 4, 2025 (SPL set 7ecd83ec-88f5-4f85-9cc2-9068375d8820), via openFDA

Source: FDA drug label (Fluvoxamine maleate extended-release), Zydus Pharmaceuticals USA Inc., effective June 27, 2026 (SPL set 6c71d4f6-54b5-4d3a-8d2f-b7773c92c32e), via openFDA; the full label on DailyMed

What does the methadone label say about fluvoxamine?

Methadone label, drug interactions

Clinical Impact: The concomitant use of methadone hydrochloride tablets and CYP3A4, CYP2B6, CYP2C19, or CYP2C9 inducers can decrease the plasma concentration of methadone, resulting in decreased efficacy or onset of withdrawal symptoms in patients physically dependent on methadone. … Intervention: If concomitant use is necessary, consider increasing the methadone hydrochloride tablets dosage until stable drug effects are achieved. Assess for signs of opioid withdrawal. …

Diskets label (Hikma Pharmaceuticals USA Inc., December 1, 2025), drug interactions

Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir), fluconazole, fluvoxamine, some selective serotonin reuptake inhibitors (SSRIs) (e.g., sertraline, fluvoxamine).

Methadose label (SpecGx LLC, April 27, 2026), drug interactions

Inhibitors of CYP3A4, CYP2B6, CYP2C19, CYP2C9, or CYP2D6 Clinical Impact: Methadone undergoes hepatic N-demethylation by several cytochrome P450 (CYP) isoforms, including CYP3A4, CYP2B6, CYP2C19, CYP2C9, and CYP2D6. The concomitant use of methadone and CYP3A4, CYP2B6, CYP2C19, CYP2C9, or CYP2D6 inhibitors can increase the plasma concentration of methadone, resulting in increased or prolonged opioid … erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir), fluconazole, fluvoxamine, some selective serotonin reuptake inhibitors (SSRIs) (e.g., sertraline, fluvoxamine)

Source: FDA drug label (Diskets, NDA017058), Hikma Pharmaceuticals USA Inc., effective December 1, 2025 (SPL set e6af84de-cbfc-4a3b-bd73-6bcf77337168), via openFDA

Source: FDA drug label (Methadose, NDA017116), SpecGx LLC, effective April 27, 2026 (SPL set 808a9d0b-720b-4034-a862-5122ff514608), via openFDA

Source: FDA drug label (Methadone Hydrochloride, NDA021624), Mylan Institutional LLC, effective December 31, 2025 (SPL set 092d78eb-6423-495c-bf0d-e6532bea7138), via openFDA

Source: FDA drug label (Methadone Hydrochloride), Epic Pharma, LLC, effective December 8, 2025 (SPL set 6da7501b-b881-4bc7-891a-74214a00a3ac), 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

16Fluvoxamine generic labelers
18Methadone generic labelers
FluvoxamineMethadone
Labeled forn/aPain, Opioid use disorder
Boxed warningYesYes
Pharmacy cost (NADAC)$4.08 per capsule 100 mg capsule$0.177 per tablet 10 mg tablet
Shortage nowNo current entryNo 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?