Table 3 Comparison of recommendation from drug interaction checkers for frequently occurring antiretroviral (ARV)- associated contraindicated and major potential drug-drug interactions
Drug 1 | Drug 2 | Proposed effect summary – Micromedexa | Scientific evidence; clinical significance – Liverpoolb | Recommended adjustment- Liverpoolb |
|---|---|---|---|---|
Atazanavir | Fluconazole | Increased atazanavir exposure and risk of QT interval prolongation | Low; no interaction expected | No prior dose adjustment necessary |
Efavirenz | Codeine | Decreased opioid efficacy | Very low; potential weak interaction | No prior dose adjustment but monitor analgesic effect |
Efavirenz | Fluconazole | Increased risk of QT interval prolongation | Moderate; no interaction expected | No dose adjustment necessary |
Efavirenz | Haloperidol | Decrease in drug 2 exposure; QT interval prolongation | Very low; potential weak interaction | No prior dose adjustment is recommended |
Efavirenz | Metronidazole | Increased risk of QT interval prolongation | Very low; no interaction expected | No dose adjustment necessary |
Efavirenz | Ondansetron | Increased risk of QT interval prolongation | Very low; no interaction expected | No dose adjustment necessary |
Efavirenz | Rifampin | Decrease in drug 1 serum concentration | High; potential weak interaction | No dose adjustment recommended in patients weighing < 50 kg |
Ritonavir | Fluconazole | Increased ritonavir exposure and risk of QT interval prolongation | Very low; no interaction expected | No prior dose adjustment recommended |
Tenofovir-DF | Atazanavir | Increase in drug 1 exposure and decrease in drug 2 exposure | Moderate; do not co-administer | Avoid co-administration, if necessary, monitor for adverse effects |
Zidovudine | Pyrazinamide | Decrease drug 2 serum concentration | Very low; no interaction expected | No dose adjustment necessary |