Mirtazapine and Posaconazole interaction
Mirtazapine and Posaconazole: 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 Mirtazapine (REMERONSOLTAB) label · effective 2025-08-06
Examples diazepam, alprazolam, alcohol Drugs that Prolong QTc Interval Clinical Impact The concomitant use of other drugs which prolong the QTc interval with REMERON/REMERONSolTab, increase the risk of QT prolongation and/or ventricular arrhythmias (e.g., Torsades de Pointes).
Exercise caution when REMERON/REMERONSolTab is prescribed in patients with known cardiovascular disease or family history of QT prolongation, and in concomitant use with other drugs thought to prolong the QTc interval.
Examples phenytoin, carbamazepine, rifampin Strong CYP3A Inhibitors Clinical Impact The concomitant use of strong CYP3A inhibitors with REMERON/REMERONSolTab may increase the plasma concentration of mirtazapine [see Clinical Pharmacology (12.3) ] .
Intervention Decrease the dose of REMERON/REMERONSolTab if needed with concomitant strong CYP3A inhibitor use.
Conversely, an increase in dosage of REMERON/REMERONSolTab may be needed if the CYP3A inhibitor is discontinued [see Dosage and Administration (2.5) ].
From the Posaconazole (NOXAFIL) label · effective 2026-02-13
Concomitant Use with Midazolam : Noxafil can prolong hypnotic/sedative effects.
Increased plasma midazolam concentrations could potentiate and prolong hypnotic and sedative effects.
Benzodiazepines that are CYP3A4 Substrates Mechanism and Clinical Effect(s) Concomitant use of posaconazole with midazolam increased midazolam plasma concentrations which could potentiate and prolong hypnotic and sedative effects [see Clinical Pharmacology (12.3) ] .
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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.