Buprenorphine and Posaconazole interaction
Buprenorphine 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 Buprenorphine (BELBUCA) label · effective 2026-01-02
Evaluate patients starting CYP3A4 inhibitors or stopping CYP3A4 inducers at frequent intervals for respiratory depression.
The risk of combining buprenorphine with other QT-prolonging agents is not known.
Inhibitors of CYP3A4 Clinical Impact: The concomitant use of BELBUCA and CYP3A4 inhibitors can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when an inhibitor is added after a stable dose of BELBUCA is achieved.
After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the buprenorphine plasma concentration will decrease [see Clinical Pharmacology (12.3) ] , potentially resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to buprenorphine.
If a CYP3A4 inhibitor is discontinued, consider increasing the BELBUCA dosage until stable drug effects are achieved.
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.