Updates to the Database of ARV Drug Interactions

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Updates to the Database of ARV Drug Interactions

HIV Meds Quarterly Reference Table, Spring/Summer 2010

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.

New ARV Interactions (April 2010-August 2010)

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