Drug or Class |
Effect or Recommendation |
Antiarrhythmics (amiodarone, bepridil, dronedarone, lidocaine, quinidine) |
Inc concentrations may lead to life-threatening arrhythmias |
Anticonvulsants |
Carbamazepine, phenobarbital, and phenytoin may reduce amprenavir concentrations. Fosamprenavir may lower phenytoin concentrations. |
Azole antifungals |
Inc concentrations of ketoconazole or itraconazole |
Atorvastatin |
May lower amprenavir concentrations |
Benzodiazepines |
Reduction of benzodiazepine dose may be needed |
Bosentan |
Reduced bosentan doses may be necessary |
Calcium channel blockers |
Close monitoring is recommended |
Colchicine |
Fosamprenavir dose reduction is necessary |
Dexamethasone |
May lower amprenavir concentrations |
Efavirenz |
Additional ritonavir is recommended when given with fosamprenavir/ritonavir once daily. No change is needed with twice daily dosing. |
Fluticasone |
Reduced cortisol concentrations; use not recommended |
H2 blockers |
May lower amprenavir concentrations |
Immunosuppressants: cyclosporine, tacrolimus, rapamycin |
Therapeutic drug monitoring recommended |
Macrolide antibiotics (clarithromycin and erythromycin) |
Use with caution, may lower amprenavir concentrations |
Nevirapine |
Not recommended with fosamprenavir alone. No dose change required when dosing fosamprenavir/ritonavir twice daily. |
Oral contraceptives |
Use not recommended; may lead to loss of virologic response |
PDE5 inhibitors: sildenafil, tadalafil, vardenafil used intermittently |
Inc PDE5 inhibitor concentrations; reduced doses of these drugs are recommended |
Paroxetine |
Fosamprenavir/ritonavir may lower paroxetine concentrations |
Rifabutin |
Reduce rifabutin dose by at least 50% and monitor for neutropenia |
Salmeterol |
Inc salmeterol concentrations; use not recommended |
Trazodone |
Inc trazodone concentrations |
Tricyclic antidepressants |
Therapeutic drug monitoring recommended |
Warfarin |
Altered warfarin concentrations; close INR monitoring recommended |
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