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; 2011 | ||||
| Atazanavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by atazanavir/ritonavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Atazanavir | Telaprevir | No dosage adjustment necessary | ||
| Darunavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by darunavir/ritonavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Darunavir | Maraviroc | Inhibition of CYP450 3A4 by darunavir/ritonavir | No dosage adjustment necessary | |
| Darunavir | Rilpivirine | Increased rilpivirine effects | No dosage adjustment necessary | |
| Darunavir 600 mg BID with ritonavir 100 mg BID x 20 days | Telaprevir 750 mg Q8H x 10 days | Decreased telaprevir effects; decreased darunavir effects | Do not coadminister Alternative agents: Atazanavir/ritonavir | |
| Darunavir 600 mg BID with ritonavir 100 mg BID x 24 days | Telaprevir 1,125 mg Q12H x 4 days | Possible telaprevir effects; decreased darunavir effects | Do not coadminister Alternative agents: Atazanavir/ritonavir | |
| Didanosine | Rilpivirine | No dosage adjustment necessary; administer didanosine on an empty stomach and at least 2 hours before or at least 4 hours after rilpivirine (which must be administered with a meal) | ||
| Efavirenz 600 mg QD x 16 days | Boceprevir 800 mg TID x 6 days | Possible decreased boceprevir effects | Do not coadminister Alternative agents: Telaprevir | |
| Efavirenz | Cisapride | Increased cisapride effects (eg, cardiac arrhythmias) | Do not coadminister Alternative agents: Metoclopramide | |
| Efavirenz | Clarithromycin | Induction of CYP450 3A4 by efavirenz | Dosage adjustment not established | |
| Efavirenz 600 mg QD x 7 days, administered with tenofovir 300 mg QD x 7 days | Telaprevir 1,125 mg Q8H x 7 days | No dosage adjustment necessary | ||
| Efavirenz 600 mg QD x 20 days | Telaprevir 750 mg Q8H x 10 days | Decreased telaprevir effects | Induction of CYP450 3A4 by efavirenz | Increase telaprevir dosage to 1,125 mg Q8H |
| Fosamprenavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by fosamprenavir/ritonavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Fosamprenavir 700 mg with ritonavir 100 mg BID x 20 days | Telaprevir 750 mg Q8H x 10 days | Decreased telaprevir effects; decreased amprenavir effects | Do not coadminister Alternative agents: Atazanavir/ritonavir | |
| Fosamprenavir 700 mg with ritonavir 100 mg BID x 24 days | Telaprevir 1,125 mg Q12H x 4 days | Do not coadminister Alternative agents: Atazanavir/ritonavir | ||
| Indinavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by indinavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Lopinavir/ritonavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by lopinavir/ritonavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Lopinavir/ritonavir | Rilpivirine | Increased rilpivirine effects | No dosage adjustment necessary | |
| Lopinavir/ritonavir | Telaprevir | Decreased telaprevir effects | Do not coadminister Alternative agents: Atazanavir/ritonavir | |
| Nelfinavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by nelfinavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Rilpivirine | Acetaminophen | No dosage adjustment necessary | ||
| Rilpivirine | Antacids | Possible decreased rilpivirine effects | Decreased gastric acidity, leading to impaired drug solubility and absorption | Administer antacids at least 2 hours before or at least 4 hours after rilpivirine |
| Rilpivirine | Atorvastatin | No dosage adjustment necessary | ||
| Rilpivirine | Chlorzoxazone | No dosage adjustment necessary | ||
| Rilpivirine | Ethinyl estradiol/norethindrone acetate | No dosage adjustment necessary | ||
| Rilpivirine 150 mg x 1 | Famotidine 40 mg x 1 taken 2 hours before rilpivirine | Decreased rilpivirine effects | Decreased gastric acidity, leading to impaired drug solubility and absorption | Administer H2 antagonist at least 12 hours before or at least 4 hours after rilpivirine |
| Rilpivirine 150 mg x 1 | Famotidine 40 mg x 1 taken 4 hours after rilpivirine | No dosage adjustment necessary | ||
| Rilpivirine 150 mg x 1 | Famotidine 40 mg x 1 taken 12 hours before rilpivirine | No dosage adjustment necessary | ||
| Rilpivirine | Ketoconazole | Decreased ketoconazole effects | No dosage adjustment necessary, but monitor for failure of antifungal therapy | |
| Rilpivirine | Methadone | Possible decreased methadone effects (eg, withdrawal) | Monitor for signs and symptoms of methadone withdrawal; some patients may need an increase in the methadone dosage | |
| Rilpivirine | Omeprazole | Decreased rilpivirine effects | Decreased gastric acidity, leading to impaired drug solubility and absorption | Do not coadminister Alternative agents: H2 antagonists, if administered at least 12 hours before or at least 4 hours after rilpivirine |
| Rilpivirine | Rifabutin | Decreased rilpivirine effects | Do not coadminister | |
| Rilpivirine | Rifampin | Decreased rilpivirine effects | Induction of CYP450 3A4 by rifampin | Do not coadminister |
| Rilpivirine | Sildenafil | No dosage adjustment necessary | ||
| Rilpivirine | Tenofovir | Possible increased tenofovir effects | No dosage adjustment necessary | |
| Ritonavir | Boceprevir | Possible decreased boceprevir effects; effect on ritonavir concentrations unknown | Clinical significance unknown, especially when combined with other PIs | |
| Ritonavir | Quinine | Increased quinine effects | Possible competitive displacement from CYP450 3A4 and inhibition of 2D6 | Avoid combination if possible; if combination must be used a potential 4-fold reduction in quinine dosage may be needed |
| Ritonavir 100 mg x 1 | Telaprevir 750 mg x 1 | Dosage adjustment not established | ||
| Ritonavir 100 mg Q12H x 14 days | Telaprevir 750 mg Q12H x 14 days | Dosage adjustment not established | ||
| Saquinavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by saquinavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
| Telaprevir 750 mg Q8H x 7 days | Tenofovir 300 mg QD x 7 days | Possible increased tenofovir effects | Dosage adjustment not established | |
| Telaprevir 1,125 mg Q8H x 7 days | Tenofovir 300 mg QD administered with efavirenz 600 mg QD x 7 days | Possible increased tenofovir effects | No dosage adjustment necessary | |
| Telaprevir 1,500 mg Q12H x 7 days | Tenofovir 300 mg QD administered with efavirenz 600 mg QD x 7 days | Possible decreased telaprevir effects | Adjust telaprevir dosage to 1,125 mg Q8H when used with efavirenz | |
| Tenofovir | Boceprevir | No dosage adjustment necessary | ||
| Tipranavir | Colchicine | Increased colchicine effects | Inhibition of CYP450 3A4 by tipranavir/ritonavir | For treatment of gout, reduce colchicine dosage to 0.6 mg x 1 then 0.3 mg 1 hour later; do not repeat dosing earlier than 3 days thereafter For prophylaxis of gout, reduce colchicine dosage to 0.3 mg QD if on 0.6 mg BID prior to PI therapy, or reduce colchicine dosage to 0.3 mg QOD if on 0.6 mg QD prior to PI therapy |
