for Health Care Providers
Updates to the Database of ARV Drug Interactions
The following table summarizes recent additions to the HIV InSite Database of Antiretroviral Drug Interactions
. For a full description of the updates, including references to the studies from which the data were derived, go to the database, click on a specific drug name, and search for the interacting agent.
| Drug One | Drug Two | Clinical Effects | Mechanisms | Management |
|---|---|---|---|---|
| Source: McNicholl I. HIV InSite Database of Antiretroviral Drug Interactions. University of California San Francisco: Center for HIV Information; 2010 | ||||
| Atazanavir | Atovaquone | Potentially compromised antimalarial activity | ↑ atovaquone glucuronidation; induction of CYP450 3A4 by atazanavir/ritonavir | Dosage adjustment not established |
| Atazanavir | Darunavir | No dosage adjustment necessary | ||
| Atazanavir (300 mg once daily) | Posaconazole (400 mg BID) | ↑ atazanavir effects | Inhibition of CYP450 3A4 by posaconazole | Dosage adjustment not established; monitor closely for adverse effects during coadministration |
| Atazanavir (300 mg once daily with 100 mg ritonavir once daily) | Posaconazole (400 mg BID) | ↑ atazanavir effects | Inhibition of CYP450 3A4 by posaconazole | Dosage adjustment not established; monitor closely for adverse effects during coadministration |
| Atazanavir | Proguanil | Potentially compromised antimalarial activity | ↑ atovaquone glucuronidation; induction of CYP450 3A4 by atazanavir/ritonavir | Dosage adjustment not established |
| Atazanavir | Raltegravir | Dosage adjustment not established | ||
| Atazanavir | Voriconazole | ↓ voriconazole effects | Possible induction of CYP450 by ritonavir | Do not coadminister |
| Darunavir | Rosuvastatin | No change in lipid-lowering ability within 35-day study period | No dosage adjustment necessary | |
| Darunavir | Voriconazole | ↓ voriconazole effects | Possible induction of CYP450 by ritonavir | Do not coadminister |
| Efavirenz | Atovaquone | Potentially compromised antimalarial activity | ↑ atovaquone glucuronidation; induction of CYP450 3A4 by efavirenz | Dosage adjustment not established |
| Efavirenz | Posaconazole | ↓ posaconazole effects | Induction of UDP-glucuronosyltransferase (UGT) by efavirenz | Dosage adjustment not established |
| Efavirenz | Proguanil | ↑ atovaquone glucuronidation; induction of CYP450 3A4 by efavirenz | Dosage adjustment not established | |
| Efavirenz (300 mg QHS for 7 days) | Voriconazole (400 mg Q12H on days 2-7) | No dosage adjustment necessary | ||
| Efavirenz 400 mg once daily for 9 days | Voriconazole (400 mg PO Q12H on day 1, then 200 mg Q12H on days 2-8) | ↑ efavirenz effects and ↓ voriconazole effects | Inhibition of CYP450 3A4 by voriconazole and induction of CYP450 3A4 by efavirenz | Do not coadminister at standard dosages; ↑ voriconazole to 400 mg Q12H and ↓ efavirenz to 300 mg QHS |
| Efavirenz (300 mg QHS for 7 days) | Voriconazole (300 mg Q12H on days 2-7) | ↓ voriconazole effects | Induction of CYP450 3A4 by efavirenz | Do not coadminister at standard dosages; ↑ voriconazole to 400 mg Q12H and ↓ efavirenz to 300 mg QHS |
| Etravirine | Itraconazole | ↓ itraconazole effects | ||
| Etravirine | Posaconazole | |||
| Indinavir | Itraconazole | ↑ indinavir effects | Inhibition of CYP450 3A4 by itraconazole | ↓ indinavir to 600 mg Q8H; do not exceed itraconazole 200 mg BID |
| Indinavir | Voriconazole | No dosage adjustment necessary | ||
| Lamivudine | Chlorpropamide | Potentially ↑ serum glucose concentrations | Consider alternative agents: Glyburide, glipizide, metformin | |
| Lopinavir/ritonavir | Atovaquone | Potentially compromised antimalarial activity | ↑ atovaquone glucuronidation; induction of CYP450 3A4 by lopinavir/ritonavir | Dosage adjustment not established |
| Lopinavir/ritonavir | Bosentan | ↑ bosentan effects | Inhibition of CYP450 3A4 by lopinavir/ritonavir | Start low and titrate bosentan to effect |
| Lopinavir/ritonavir | Gemfibrozil | ↓ gemfibrozil effects | Reduced gemfibrozil absorption owing to lopinavir/ritonavir | Potential option includes utilizing alternative antiretrovirals; unknown whether fenofibrate has same interaction as gemfibrozil |
| Lopinavir/ritonavir | Proguanil | Potentially compromised antimalarial activity | ↑ atovaquone glucuronidation; induction of CYP450 3A4 by lopinavir/ritonavir | Dosage adjustment not established |
| Lopinavir/ritonavir | Rifampin | ↓ lopinavir effects at lower dosages | Induction of CYP450 3A4 by rifampin | Lopinavir/ritonavir dosage of 800/200 mg Q12H appears to compensate for rifampin-induced 3A4 induction |
| Nevirapine | Chlorpropamide | |||
| Raltegravir | Pravastatin | No dosage adjustment necessary | ||
| Ritonavir | Posaconazole | Possibly ↑ ritonavir effects | Inhibition of CYP450 3A4 by posaconazole; potential inhibition of UGT 1A1 by atazanavir | Dosage adjustment not necessary |
| Ritonavir (100 mg Q12H for 9 days) | Voriconazole (400 mg Q12H) | ↓ voriconazole effects | Induction of CYP450 3A4 by ritonavir | Avoid coadministration; consider use of non-ritonavir-containing antiretroviral regimens |
| Ritonavir (400 mg Q12H for 9 days) | Voriconazole (400 mg Q12H) | ↓ voriconazole effects | Induction of CYP450 3A4 by ritonavir | Do not coadminister |
| Saquinavir | Itraconazole | ↑ itraconazole effects; ↑ saquinavir effects | Inhibition of CYP450 3A4 by itraconazole and saquinavir and ritonavir | Consider reducing itraconazole to 100 mg BID |
| Saquinavir | Ketoconazole | ↑ saquinavir effects | Inhibition of CYP450 3A4 by ketoconazole | Dosage adjustment not established |
| Saquinavir | Methadone | ↓ methadone effects (eg, withdrawal) | Monitor for signs and symptoms of methadone withdrawal; some patients may need ↑ in methadone dosage | |
| Stavudine | Chlorpropamide | Potentially ↑ serum glucose concentrations | Consider alternative agents: Glyburide, glipizide, metformin | |
| Tenofovir | Saquinavir | No dosage adjustment necessary | ||
