No pharmaceutical opinion available for this interaction.
Atazanavir / ritonavir may possibly inhibit the metabolism (CYP 3A4) and consequently increase the plasma concentration of Alprazolam.
3A4, P-gp/3A4 > 2D6, P-gp
Ritonavir: 1A2, 2C9, 2C19, UGT, 2B6, 3A4 (auto-induction)
3A4, UGT1A1, P-gp E et 2C8/3A4 > 2D6 > 2A6, 2E1, P-gp, MRP2
Increased risk of CNS toxicity.
Risk of prolonged sedation and respiratory depression.
Start at a low dose then increase gradually according to efficacy and tolerance.
If patient already on hypnotics/sedatives and antiretroviral therapy is started, reduce the dose and gradually increase depending on efficacy and safety.
In patients already being treated with this combination and tolerating it, if deemed appropriate, keep actual treatment and exercise close monitoring of adverse effects and clinical effectiveness.
Lorazepam (Ativan), temazepam (Restoril), oxazepam (Serax)
Benzodiazepine toxicity: drowsiness, dizziness, ataxia, problem of coordination, confusion, decrease of reflexes, excessive sedation, respiratory depression and coma.
Ref #1307 : In a short-term study, co-administration of alprazolam 1mg with 4 doses of ritonavir 200 mg BID increased alprazolam AUC by 2.5-fold.
Ref #169 : But in this study with steady-state ritonavir, co-administration of alprazolam 1mg with ritonavir 500 mg BID for 10 days decreased alprazolam AUC by 12%.