Ritocom Drug Interactions

See also Contraindications and Pharmacology: Pharmacokinetics under Actions.
Potential for Lopinavir and Ritonavir to Affect Other Drugs: Lopinavir/ritonavir is an inhibitor of CYP3A and may increase plasma concentrations of agents that are primarily metabolized by CYP3A. Agents that are extensively metabolized by CYP3A and have high first pass metabolism appear to be the most susceptible to large increases in AUC (> 3-fold) when co-administered with lopinavir and ritonavir. Thus, co-administration of lopinavir and ritonavir with drugs highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events is contraindicated. Co-administration with other CYP3A substrates may require a dose adjustment or additional monitoring as shown in Table 17.
Additionally, lopinavir and ritonavir induces glucuronidation.
Potential For Other Drugs To Affect Lopinavir: Lopinavir/ritonavir is a CYP3A substrate; therefore, drugs that induce CYP3A may decrease lopinavir plasma concentrations and reduce lopinavir and ritonavir's therapeutic effect. Although not observed in the lopinavir and ritonavir/ketoconazole drug interaction study, co-administration of lopinavir and ritonavir and other drugs that inhibit CYP3A may increase lopinavir plasma concentrations.
Established and Other Potentially Significant Drug Interactions: Table 17 provides a listing of established or potentially clinically significant drug interactions. Alteration in dose or regimen may be recommended based on drug interaction studies or predicted interaction. (See Pharmacology: Pharmacokinetics under Actions for magnitude of interaction). (See Table 17a, Table 17b and Table 17c.)

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Drugs with No Observed or Predicted Interactions with Lopinavir and Ritonavir: Drug interaction studies reveal no clinically significant interaction between lopinavir and ritonavir and desipramine (CYP2D6 probe), pravastatin, stavudine, lamivudine, omeprazole or ranitidine.
Based on known metabolic profiles, clinically significant drug interactions are not expected between lopinavir and ritonavir and fluvastatin, dapsone, trimethoprim/sulfamethoxazole, azithromycin, erythromycin, or fluconazole.