Ritonavir, a potent inhibitor of cytochrome P450 3A4 (CYP3A4) and CYP2D6, can cause clinically significant increases in serum levels of other protease inhibitors (PIs). Pharmacokinetic enhancement of certain PIs with low-dose ritonavir can increase drug concentrations of these PIs while allowing a reduction in pill burden, dosing frequency, and food restrictions. The following table shows evidence-based possibilities for adult dosages of ritonavir-boosted PIs. Not all are approved by the U.S. Food and Drug Administration. For more information, see the Database of Antiretroviral Drug Interactions. | Protease Inhibitor | Adult Dosing Options |
|---|
Abbreviations: BID = 2 times per day; QD = once daily * When used in combination with efavirenz or nevirapine, may require dosage adjustment. See Dosage Adjustments for ARV-ARV Drug Interactions. # Once-daily dosing of darunavir, fosamprenavir, lopinavir, or saquinavir is not recommended for PI-experienced patients. § Once-daily lopinavir/ritonavir should not be used in combination with efavirenz, nevirapine, amprenavir, fosamprenavir, or nelfinavir (dosage adjustment not established). Once-daily dosing of lopinavir/ritonavir should not be used for pregnant women, patients receiving hemodialysis, or patients with ≥3 mutations associated with resistance to lopinavir/ritonavir. ** When used in combination with efavirenz; when used in combination with tenofovir and an H2 receptor antagonist. | | Atazanavir | Atazanavir 300 mg QD + ritonavir 100 mg QD | | Atazanavir 400 mg QD + ritonavir 100 mg QD** | | Darunavir | Darunavir 600 mg BID + ritonavir 100 mg BID | | Darunavir 800 mg QD + ritonavir 100 mg QD # | | Fosamprenavir | Fosamprenavir 700 mg BID + ritonavir 100 mg BID* | | Fosamprenavir 1,400 mg QD + ritonavir 200 mg QD* # | | Fosamprenavir 1,400 mg QD + ritonavir 100 mg QD* # | | Indinavir | Indinavir 800 mg BID + ritonavir 100 mg BID* | | Indinavir 800 mg BID + ritonavir 200 mg BID* | | Indinavir 400 mg BID + ritonavir 400 mg BID* | | Lopinavir | Lopinavir 400 mg + ritonavir 100 mg BID (coformulated as Kaletra)* | | Lopinavir 800 mg + ritonavir 200 mg QD (coformulated as Kaletra)# § | | Saquinavir | Saquinavir 1,000 mg BID + ritonavir 100 mg BID | | Saquinavir 1,600 mg QD + ritonavir 100 mg QD# | | Saquinavir 400 mg BID + ritonavir 400 mg BID | | Tipranavir | Tipranavir 500 mg BID + ritonavir 200 mg BID |
|
HIV InSite is a project of the UCSF Center for HIV Information. Copyright 2013, Regents of the University of California.