Isoniazid and Viloxazine interaction
Isoniazid and Viloxazine: the Viloxazine prescribing label flags 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 Viloxazine (QELBREE) label · effective 2025-12-05
Qelbree is contraindicated in patients: receiving concomitant treatment with monoamine oxidase inhibitors (MAOI), or within 14 days following discontinuing an MAOI, because of an increased risk of hypertensive crisis [see Drug Interactions (7.1) ] . receiving concomitant administration of sensitive CYP1A2 substrates or CYP1A2 substrates with a narrow therapeutic…
Concomitant administration of monoamine oxidase inhibitors (MAOI), or dosing within 14 days after discontinuing an MAOI ( 4 , 7.1 )
Drugs Having Clinically Important Interactions with Qelbree Table 3: Clinically Important Drug Interactions with Qelbree Monoamine Oxidase Inhibitors (MAOI) Clinical Impact Concomitant use of Qelbree with an MAOI may lead to a potentially life-threatening hypertensive crisis.
Intervention Concomitant use of Qelbree with an MAOI or within 2 weeks after discontinuing an MAOI is contraindicated [see Contraindications (4) ] .
CYP3A4 Substrates Clinical Impact Viloxazine is a weak inhibitor of CYP3A4 which increases the exposure of CYP3A4 substrates when coadministered [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.