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What the FDA labels say about taking them together

Mirtazapine and naloxone/pentazocine

Naloxone/pentazocine's FDA label of August 28, 2025 names mirtazapine in its drug interactions section; the mirtazapine label PlainMeds reads does not name naloxone/pentazocine. The naloxone/pentazocine label: “Serotonergic Drugs The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system, such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake …”

Check it at the source: the mirtazapine FDA label on DailyMed (effective August 6, 2025, Organon LLC); the naloxone/pentazocine FDA label on DailyMed (effective August 28, 2025, Lupin Pharmaceuticals,Inc.).

What does the mirtazapine label say about naloxone/pentazocine?

Mirtazapine's label (effective August 6, 2025) does not name naloxone/pentazocine in these sections. A label lists what its studies and reports found; it is not a complete list.

Source: FDA drug label (REMERON), Organon LLC, effective August 6, 2025 (SPL set 98ad1917-a094-44f5-a28f-a64a8cfcd887), via openFDA; the full label on DailyMed

What does the naloxone/pentazocine label say about mirtazapine?

Naloxone/pentazocine label, drug interactions

Serotonergic Drugs The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system, such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue), has resulted in serotonin syndrome. [see PRECAUTIONS;

Source: FDA drug label (PENTAZOCINE HYDROCHLORIDE AND NALOXONE HYDROCHLORIDE), Lupin Pharmaceuticals,Inc., effective August 28, 2025 (SPL set 017ef042-40aa-44c9-baa8-037f06356845), 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

36Mirtazapine generic labelers
3Naloxone/pentazocine generic labelers
MirtazapineNaloxone/pentazocine
Labeled forDepressionPain
Boxed warningYesYes
Pharmacy cost (NADAC)$0.063 per tablet 15 mg tablet$2.06 per tablet Pentazocine-naloxone 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)

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