https://interactions.guidetherapeutiquevih.com/en/interaction-details?id=9906
https://interactions.guidetherapeutiquevih.com/en/interaction-details?id=9906
No pharmaceutical opinion available for this interaction.
Ritonavir may possibly inhibit the metabolism (CYP 2D6 and 3A4) and consequently increase the concentration of Mirtazapine.
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Possible increase of adverse effects.
Increased risk of QT interval prolongation.
Start with the lowest dose possible, or in patients already on treatment, a dose reduction may be necessary.
Monitor closely clinical efficacy and appearance of adverse effects.
In patients already being treated with this combination and tolerating it, if deemed appropriate, keep actual treatment and exercise close monitoring of adverse effects.
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Mirtazapine adverse effects: drowsiness, dry mouth, increased appetite, gain of weight, constipation, dizziness and headaches.
QT interval in patients with possible electrolyte disorders or other risk factors for QT prolongation.
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Ref #2626 : Mirtazapine product monograph recommends caution when co-administered with CYP2D6 inhibitors or strong CYP3A4 inhibitors. Indeed, co-administration of mirtazapine (30 mg single dose) and ketoconazole, a strong CYP 3A4 inhibitor (200 mg BID for 6.5 days) resulted in an increase of approximately 50% and 40%, respectively, in mirtazapine AUC and Cmax.
Ref #2839 : Using a physiologically based pharmacokinetic modelling approach, the interaction with ritonavir resulted in a 52% increase in mirtazapine AUC.