for Health Care Providers
Updates to the Database of ARV Drug Interactions
The following table summarizes recent additions to the HIV InSite . 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; 2011. | ||||
| Atazanavir | Pitavastatin | Possibly ↑ pitavastatin effects | Start at lowest dosage and titrate to effect | |
| Atazanavir (atazanavir 300 mg QD with ritonavir 100 mg QD) | Rosuvastatin | ↑ rosuvastatin effects | Do not coadminister Alternative agents: pravastatin, atorvastatin | |
| Darunavir | Buprenorphine | Inhibition of CYP450 3A4 by darunavir/ritonavir | No dosage adjustment necessary | |
| Darunavir | Methadone | May ↓ methadone effects (eg, withdrawal) | Monitor for signs and symptoms of methadone withdrawal; some patients may need ↑ in the methadone dosage | |
| Darunavir | Nevirapine | Possibly ↑ darunavir effects; possibly ↑ nevirapine effects | No dosage adjustment necessary | |
| Darunavir | Rifabutin | ↑ darunavir and rifabutin effects | Inhibition of CYP450 3A4 by darunavir | ↓ rifabutin dosage to 150 mg QOD when combined with darunavir/ritonavir |
| Darunavir | Rosuvastatin | No change in lipid-lowering ability within 35-day study period | Avoid coadministration if possible; if used, use caution and start at 5 mg daily | |
| Efavirenz (400 mg QD) | Proguanil (300 mg, single dose) | Possibly ↓ antimalarial effects | Possible inhibition of CYP450 2C19 by efavirenz; possible induction of P-gp by efavirenz | Dosage adjustment not established |
| Efavirenz (600 mg QHS) | Proguanil (100 mg with 250 mg atovaquone, single dose) | ↑ atovaquone glucuronidation; induction of CYP450 3A4 by efavirenz | Dosage adjustment not established | |
| Etravirine (200 mg BID with darunavir/ritonavir 600/100 mg BID) | Maraviroc | ↑ maraviroc effects | Inhibition of CYP450 3A4 by darunavir/ritonavir | ↓ maraviroc to 150 mg BID |
| Etravirine (200 mg BID) | Maraviroc | Induction of CYP450 3A4 by etravirine | ↑ maraviroc to 600 mg BID when used with etravirine | |
| Fosamprenavir | Paroxetine | ↓ paroxetine effects | Titrate paroxetine to effect | |
| Fosamprenavir | Rosuvastatin | No dosage adjustment necessary | ||
| Indinavir | Atovaquone | No dosage adjustment necessary | ||
| Lopinavir/ritonavir | Bupropion | ↑ bupropion effects | Possible induction of CYP450 2B6 and UGT enzymes | |
| Lopinavir/ritonavir | Echinacea | No dosage adjustment necessary | ||
| Lopinavir/ritonavir | Ketoconazole | ↑ ketoconazole effects; ↓ lopinavir/ritonavir effects | Manufacturer recommends against using high dosages of ketoconazole (>200 mg daily) Alternative agents: fluconazole | |
| Lopinavir/ritonavir | Rosuvastatin | ↑ rosuvastatin effects | Do not coadminister Alternative agents: pravastatin, atorvastatin | |
| Maraviroc | Raltegravir | No dosage adjustment necessary | ||
| Raltegravir | Antacids | No dosage adjustment necessary | ||
| Ritonavir | Colchicine | ↑ colchicine effects | Inhibition of CYP450 3A4 by ritonavir | For treatment of gout, ↓ colchicine dosage to 0.6 mg for a single dose, then 0.3 mg 1 hour later; dose not to be repeated earlier than 3 days; for prophylaxis of gout, ↓ colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy or ↓ colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Ritonavir (200 mg BID) | Tadalafil | ↑ tadalafil effects (eg, hypotension, priapism) | Inhibition of CYP450 3A4 by ritonavir | Do not exceed 10 mg tadalafil every 72 hours |
| Ritonavir (500 mg or 600 mg BID) | Tadalafil | ↑ tadalafil effects (eg, hypotension, priapism) | Inhibition of CYP450 3A4 by ritonavir | Do not exceed 10 mg tadalafil every 72 hours |
| Zidovudine | Atovaquone | ↑ zidovudine effects | Inhibition of glucuronidation by atovaquone | No dosage adjustment necessary |
