fosamprenavir (Rx)

Brand and Other Names:Lexiva
  • Print

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 700mg

oral suspension

  • 50mg/mL

HIV Infection

Therapy-naive patients

  • 1400 mg PO q12hr (without ritonavir)
  • 1400 mg PO qDay (with ritonavir 100-200 mg qDay)
  • 700 mg PO q12hr (with ritonavir 100 mg q12hr)

Protease inhibitor-experienced patients

  • 700 mg PO q12hr (with ritonavir 100 mg q12hr)

Coadministration with efavirenz

  • 700 mg PO q12hr (with ritonavir 100 mg q12hr) plus 600 mg efavirenz qDay, or
  • 1400 mg PO qDay (with ritonavir 300 mg qDay) plus 600 mg efavirenz qDay

Combination with maraviroc

  • 700 mg PO q12hr (with ritonavir 100 mg q12hr) plus maraviroc 150 mg PO q12hr

Pregnant women on fosamprenavir plus ritonavir

  • Indicated for pregnant women who are already on a stable twice-daily regimen of fosamprenavir/ritonavir 700 mg/100 mg before pregnancy and are virologically suppressed (HIV-1 RNA <50 copies/mL)
  • 700 mg PO q12hr (with ritonavir 100 mg q12hr)
  • Lower exposures of amprenavir (active moiety) observed during pregnancy; therefore, closely monitor viral load to ensure viral suppression is maintained

Hepatic Impairment

Mild (Child-Pugh 5-6): 700 mg PO q12hr without ritonavir (therapy-naive); OR 700 mg q12hr with ritonavir 100 mg qDay (therapy-naive or protease inhibitor-experienced)

Moderate (Child-Pugh 7-9): 700 mg PO q12hr (therapy-naive) without ritonavir; OR 450 mg q12hr with ritonavir 100 mg qDay (therapy-naive or protease inhibitor-experienced)

Severe (Child-Pugh 10-15): 350 mg PO q12hr without ritonavir (therapy-naive); OR 300 mg q12hr with ritonavir 100 mg qD (therapy-naive or protease-inhibitor experienced)

Dosage Forms & Strengths

tablet

  • 700mg

oral suspension

  • 50mg/mL

HIV Infection

Protease inhibitor naïve patients

  • <4 weeks: Safety and efficacy not established
  • Indicated for protease inhibitor-naive pediatric patients aged 4 weeks or older, and for protease inhibitor-experienced children aged 6 months or older
  • For infants, use only in those born at 38 weeks' gestation or greater and who have attained a postnatal age of 28 days
  • <11 kg: 45 mg/kg PO q12hr plus ritonavir 7 mg/kg q12hr
  • 11 to <15 kg: 30 mg/kg PO q12hr plus ritonavir 3 mg/kg q12hr
  • 15 kg to <20 kg: 23 mg/kg PO q12hr plus ritonavir 3 mg/kg q12hr
  • ≥20 kg: 18 mg/kg PO q12hr plus ritonavir 3 mg/kg q12hr
  • NOTE: When dosing with ritonavir, do not exceed adult dose of 700 mg/ritonavir 100 mg q12hr
  • Alternatively, protease inhibitor-naive children aged 2 yr or older may be administered 30 mg/kg PO q12hr (without ritonavir)
  • Unboosted regimen
    • <2 years: Not recommended without ritonavir
    • ≥2 years and <47 kg: 30 mg/kg/dose PO q12hr; not to exceed 1400 mg PO q12hr
    • ≥2 years and ≥47 kg: 1400 mg PO q12hr

Protease inhibitor experienced patients

  • <6 months: Safety and efficacy not established
  • ≥6 months
    • <11 kg: 45 mg/kg/dose PO q12hr; not to exceed 700 mg fosamprenavir/100 mg ritonavir PO q12hr
    • 11-15 kg: 30 mg/kg/dose PO q12hr plus 3 mg/kg/dose ritonavir PO q12hr; not to exceed 700 mg fosamprenavir/100 mg ritonavir PO q12hr
    • 15 to <20 kg: 23 mg/kg/dose PO q12hr plus 3 mg/kg/dose ritonavir PO q12hr; not to exceed 700 mg fosamprenavir/100 mg ritonavir PO q12hr
    • ≥20 kg: 18 mg/kg/dose PO q12hr plus 3 mg/kg/dose ritonavir PO q12hr; not to exceed 700 mg fosamprenavir/100 mg ritonavir PO q12hr
Next:

Interactions

Interaction Checker

and fosamprenavir

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            All Interactions Sort By:
             activity indicator 

            Contraindicated (24)

            • alfuzosin

              fosamprenavir will increase the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • cobimetinib

              fosamprenavir will increase the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Avoid coadministration with strong CYP3A4 inhibitors with (increases cobimetinib systemic exposure by 6.7-fold).

            • conivaptan

              fosamprenavir will increase the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of conivaptan with strong CYP3A4 inhibitors is contraindicated.

            • dihydroergotamine

              fosamprenavir will increase the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • dihydroergotamine intranasal

              fosamprenavir will increase the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • eliglustat

              fosamprenavir will increase the level or effect of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors are contraindicated with eliglustat poor or intermediate metabolizers; reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors

            • elvitegravir/cobicistat/emtricitabine/tenofovir DF

              fosamprenavir, elvitegravir/cobicistat/emtricitabine/tenofovir DF. Other (see comment). Contraindicated. Comment: Elvitegravir/cobicistat/emtricitabine/tenofovir is a complete regimen for HIV and should not be administered with other antiretrovirals.

            • etravirine

              etravirine increases levels of fosamprenavir by decreasing metabolism. Contraindicated. Etravirine should not be co-administered with fosamprenavir, either with or without low-dose ritonavir.

            • flibanserin

              fosamprenavir will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of flibanserin with moderate or strong CYP3A4 inhibitors is contraindicated. Severe hypotension or syncope can occur.

            • irinotecan

              fosamprenavir will increase the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • irinotecan liposomal

              fosamprenavir will increase the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • ivabradine

              fosamprenavir will increase the level or effect of ivabradine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of ivabradine with strong CYP3A4 inhibitors is contraindicated.

            • lomitapide

              fosamprenavir increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increases lomitapide levels several folds.

            • lonafarnib

              fosamprenavir will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is a sensitive CYP3A4 substrate. Coadministration with strong or moderate CYP3A4 inhibitors is contraindicated.

            • lovastatin

              fosamprenavir will increase the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors increase systemic statin exposure and risk of myopathy, including rhabdomyolysis

            • lurasidone

              fosamprenavir increases levels of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of lurasidone and strong CYP3A4 inhibitors is contraindicated.

            • naloxegol

              fosamprenavir will increase the level or effect of naloxegol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of naloxegol with strong CYP3A4 inhibitors can significantly increase naloxegol systemic exposure which may precipitate opioid withdrawal symptoms

            • pimozide

              fosamprenavir increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.

            • regorafenib

              fosamprenavir, regorafenib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors increase regorafenib levels and decrease exposure of the active metabolites M-2 and M-5.

            • rifampin

              rifampin decreases levels of fosamprenavir by increasing metabolism. Contraindicated. Contraindicated. May result in loss of antiviral efficacy and/or development of viral resistance.

            • salmeterol

              fosamprenavir increases levels of salmeterol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potential for increased toxicity. .

            • simvastatin

              fosamprenavir will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Contraindicated. Increased risk for rhabdomyolysis with drugs that increase simvastatin systemic exposure

            • St John's Wort

              St John's Wort will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • venetoclax

              fosamprenavir will increase the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Use of strong CYP3A4 inhibitors is contraindicated with venetoclax during the initial ramp-up dosing phase. If a strong CYP3A inhibitor must be used after the ramp-up phase, reduce the venetoclax dose by at least 75%.

            Serious - Use Alternative (123)

            • abametapir

              abametapir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

            • acalabrutinib

              fosamprenavir will increase the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of acalabrutinib with strong CYP3A inhibitors. If a strong CYP3A inhibitor must be used short-term (eg, up to 7 days), temporarily interrupt treatment with acalabrutinib.

            • ado-trastuzumab emtansine

              fosamprenavir increases levels of ado-trastuzumab emtansine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. DM1, the cytotoxic component, is metabolized mainly by CYP3A4; strong CYP3A4 inhibitors may increase DM1 exposure and toxicity.

            • amiodarone

              fosamprenavir will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • amitriptyline

              fosamprenavir increases levels of amitriptyline by decreasing metabolism. Avoid or Use Alternate Drug.

            • amoxapine

              fosamprenavir increases levels of amoxapine by decreasing metabolism. Avoid or Use Alternate Drug.

            • apalutamide

              apalutamide will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

            • atorvastatin

              fosamprenavir will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Limit atorvastatin dose to 20 mg/day

            • avanafil

              fosamprenavir will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP3A4 inhibitors may reduce avanafil clearance increasing systemic exposure to avanafil; significantly increased levels may result in significant adverse events including severe hypotension, syncope, visual changes, and priapism. Coadministration with strong CYP3A4 is contraindicated.

            • avapritinib

              fosamprenavir will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of avapritinib with moderate CYP3A4 inhibitors. If unable to avoid, reduce avapritinib starting dose. See drug monograph Dosage Modifications.

            • axitinib

              fosamprenavir increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, reduce axitinib dose by 50%.

            • bedaquiline

              fosamprenavir will increase the level or effect of bedaquiline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of bedaquiline with strong CYP3A4 inhibitors for >14 consecutive days, unless the benefit of treatment outweighs the risk

            • bosentan

              bosentan will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. stop bosentan >36 hours prior to PI initiation and restart 10 days after PI initiation at 62.5 mg once daily or every other day.

            • bosutinib

              fosamprenavir increases levels of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inhibitors increases bosutinib plasma concentration ~5-fold.

            • brigatinib

              fosamprenavir will increase the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a strong CYP3A inhibitor cannot be avoided, reduce the brigatinib once daily dose by about 50% (ie, from 180 mg to 90 mg, or from 90 mg to 60 mg). After discontinuation of a strong CYP3A inhibitor, resume the brigatinib dose that was tolerated prior to initiating the strong CYP3A inhibitor.

            • cabergoline

              fosamprenavir increases levels of cabergoline by decreasing metabolism. Contraindicated.

            • cabotegravir

              fosamprenavir, cabotegravir. Other (see comment). Avoid or Use Alternate Drug. Comment: Cabotegravir plus rilpivirine is a complete regimen. Coadministration with other antiretroviral medications for treating HIV-1 infection is not recommended.

            • cabozantinib

              fosamprenavir will increase the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of cabozantinib with strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor is required, decrease cabozantinib dose by 40 mg/day (Cometriq) or by 20 mg/day (Cabometyx). Resume previous dose 2-3 days after strong CYP3A4 inhibitor discontinued.

            • carbamazepine

              carbamazepine will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ceritinib

              fosamprenavir increases levels of ceritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid if possible; if concomitant use is unavoidable, reduce ceritinib dose by ~33%; after discontinuation of strong CYP3A inhibitor, resume at previous dose.

            • cimetidine

              cimetidine will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • clarithromycin

              clarithromycin will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • clomipramine

              fosamprenavir increases levels of clomipramine by decreasing metabolism. Avoid or Use Alternate Drug.

            • colchicine

              fosamprenavir will increase the level or effect of colchicine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid use of colchicine with strong CYP3A4 inhibitors. If coadministration is necessary, decrease colchicine dose or frequency as recommended in prescribing information. Use of any colchicine product in conjunction with strong CYP3A4 inhibitors is contraindicated in patients with renal or hepatic impairment.

            • copanlisib

              fosamprenavir will increase the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use with strong CYP3A inhibitors cannot be avoided, reduce copanlisib dose to 45 mg.

            • dabrafenib

              fosamprenavir increases levels of dabrafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • desipramine

              fosamprenavir increases levels of desipramine by decreasing metabolism. Avoid or Use Alternate Drug.

            • dolutegravir

              fosamprenavir will decrease the level or effect of dolutegravir by increasing metabolism. Avoid or Use Alternate Drug. Increase dolutegravir dose to 50 mg BID when coadministered with strong UGT1A/CYP3A inducers (eg, fosamprenavir/ritonavir)

            • dosulepin

              fosamprenavir increases levels of dosulepin by decreasing metabolism. Avoid or Use Alternate Drug.

            • doxepin

              fosamprenavir increases levels of doxepin by decreasing metabolism. Avoid or Use Alternate Drug.

            • dronedarone

              fosamprenavir will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • encorafenib

              fosamprenavir will increase the level or effect of encorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a strong CYP3A4 inhibitor is unavoidable, reduce encorafenib dose to one-third of the dose (eg, reduce from 450 mg/day to 150 mg/day). After discontinuing the inhibitor for 3-5 elimination half-lives, resume previous encorafenib dose.

            • entrectinib

              fosamprenavir will increase the level or effect of entrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of moderate CYP3A4 inhibitors with entrectinib, a CYP3A4 substrate. If coadministration unavoidable, reduce dose to 200 mg/day for patients aged 12 y or older with BSA >1.50m2. Resume previous entrectinib dose after discontinuing moderate CYP3A inhibitor for 3-5 elimination half-lives.

            • enzalutamide

              enzalutamide will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erdafitinib

              erdafitinib will increase the level or effect of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

            • ergoloid mesylates

              fosamprenavir increases levels of ergoloid mesylates by decreasing metabolism. Contraindicated.

            • ergotamine

              fosamprenavir will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

              fosamprenavir increases levels of ergotamine by decreasing metabolism. Contraindicated.

            • erythromycin base

              erythromycin base will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              fosamprenavir will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • erythromycin ethylsuccinate

              erythromycin ethylsuccinate will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              fosamprenavir will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • erythromycin lactobionate

              erythromycin lactobionate will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              fosamprenavir will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • erythromycin stearate

              erythromycin stearate will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              fosamprenavir will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • ethinylestradiol

              fosamprenavir, ethinylestradiol. unspecified interaction mechanism. Avoid or Use Alternate Drug. Coadministration may decrease amprenavir AUC, and may lead to loss of virologic response. Coadministration of fosamprenavir with ethinyl estradiol may alter hormone levels. Alternative methods of nonhormonal contraception are recommended.

            • etravirine

              etravirine will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • everolimus

              fosamprenavir will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • fentanyl

              fosamprenavir will increase the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

            • fentanyl intranasal

              fosamprenavir will increase the level or effect of fentanyl intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

            • fentanyl transdermal

              fosamprenavir will increase the level or effect of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

            • fentanyl transmucosal

              fosamprenavir will increase the level or effect of fentanyl transmucosal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

            • fexinidazole

              fexinidazole will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

            • fluticasone intranasal

              fosamprenavir will increase the level or effect of fluticasone intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inhibitors may increase systemic corticosteroid adverse effects; monitor for signs/symptoms of high corticosteroid concentrations including Cushing type signs/symptoms.

            • ibrutinib

              fosamprenavir increases levels of ibrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for =7 days), interrupt ibrutinib therapy until strong CYP3A4 inhibitor is discontinued.

            • idelalisib

              fosamprenavir will increase the level or effect of idelalisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministered with strong CYP3A inhibitors, monitor for signs of idelalisib toxicity; follow recommendations for dosage modifications if adverse reactions occur

              idelalisib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

            • imipramine

              fosamprenavir increases levels of imipramine by decreasing metabolism. Avoid or Use Alternate Drug.

            • infigratinib

              fosamprenavir will increase the level or effect of infigratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • itraconazole

              itraconazole will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Do not exceed itraconazole dose to 200 mg/day in patients receiving fosamprenavir/ritonavir. In patients receiving fosamprenavir alone, dose reductions may be needed for patients receiving itraconazole doses greater than 400 mg/day.

            • ivosidenib

              fosamprenavir will increase the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP3A4 inhibitors with ivosidenib or replace with alternate therapies. If coadministration of a strong CYP3A4 inhibitor is unavoidable, reduce ivosidenib dose to 250 mg qDay. If the strong inhibitor is discontinued, increase ivosidenib dose (after at least 5 half-lives of the strong CYP3A4 inhibitor) to the recommended dose of 500 mg qDay. Monitor for increased risk of QTc interval prolongation.

              ivosidenib will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

            • ketoconazole

              ketoconazole will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lemborexant

              fosamprenavir will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lemborexant with moderate or strong CYP3A inhibitors.

            • lidocaine

              fosamprenavir increases levels of lidocaine by unspecified interaction mechanism. Avoid or Use Alternate Drug.

            • lofepramine

              fosamprenavir increases levels of lofepramine by decreasing metabolism. Avoid or Use Alternate Drug.

            • lonafarnib

              lonafarnib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

            • lopinavir

              lopinavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lorlatinib

              lorlatinib will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lurbinectedin

              fosamprenavir will increase the level or effect of lurbinectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • macitentan

              fosamprenavir will increase the level or effect of macitentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministering macitentan with strong CYP3A4 inhibitors

            • maprotiline

              fosamprenavir increases levels of maprotiline by decreasing metabolism. Avoid or Use Alternate Drug.

            • mefloquine

              fosamprenavir increases levels of mefloquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Avoid coadministration during and for 15 weeks after discontinuing mefloquine. .

            • methylergonovine

              fosamprenavir increases levels of methylergonovine by decreasing metabolism. Contraindicated.

            • midazolam

              fosamprenavir increases levels of midazolam by decreasing metabolism. Contraindicated.

            • midazolam intranasal

              fosamprenavir will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of moderate CYP3A4 inhibitors with midazolam intranasal causes higher midazolam systemic exposure, which may prolong sedation.

            • midostaurin

              fosamprenavir will increase the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong CYP3A4 inhibitors cannot be avoided, monitor midostaurin for increased risk of adverse reactions, especially during the first week of treatment.

            • mifepristone

              mifepristone will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • mobocertinib

              fosamprenavir will increase the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If use of moderate CYP3A4 inhibitor unavoidable, reduce mobocertinib dose by ~50% (eg, 160 to 80 mg); closely monitor QTc interval.

            • nefazodone

              nefazodone will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • neratinib

              fosamprenavir will increase the level or effect of neratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of neratinib with strong/moderate CYP3A4 inhibitors.

            • nortriptyline

              fosamprenavir increases levels of nortriptyline by decreasing metabolism. Avoid or Use Alternate Drug.

            • olaparib

              fosamprenavir will increase the level or effect of olaparib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with moderate CYP3A inhibitors cannot be avoided, reduce olaparib dose to 200 mg (capsule) or 150 mg (tablet) PO BID. Do not substitute tablets with capsules.

            • osimertinib

              fosamprenavir will increase the level or effect of osimertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of osimertinib with strong CYP3A4 inhibitors. If no other alternative treatment exists, monitor patient more closely for adverse effects.

            • oxycodone

              fosamprenavir increases levels of oxycodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Oxycodone dose reduction may be warranted when coadministered with strong CYP3A4 inhibitors .

            • palbociclib

              fosamprenavir will increase the level or effect of palbociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of palbociclib with strong CYP3A inhibitors. If unable to avoid, reduce palbociclib dose to 75 mg/day.

            • pazopanib

              fosamprenavir will increase the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with strong CYP3A4 inhibitors if possible; if must coadminister, decrease pazopanib dose to 400 mg/day

            • pemigatinib

              fosamprenavir will increase the level or effect of pemigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.

            • pexidartinib

              fosamprenavir will increase the level or effect of pexidartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pexidartinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pexidartinib dose.

            • pimavanserin

              fosamprenavir will increase the level or effect of pimavanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Decrease dose to 17 mg/day if pimavanserin is coadministered with strong CYP3A4 inhibitors.

            • pomalidomide

              fosamprenavir increases levels of pomalidomide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ponatinib

              fosamprenavir increases levels of ponatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Decrease ponatinib starting dose to 30 mg qDay if coadministration with strong CYP3A4 inhibitors cannot be avoided.

            • protriptyline

              fosamprenavir increases levels of protriptyline by decreasing metabolism. Avoid or Use Alternate Drug.

            • quinidine

              fosamprenavir increases levels of quinidine by unspecified interaction mechanism. Avoid or Use Alternate Drug.

            • ranolazine

              fosamprenavir will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • red yeast rice

              fosamprenavir will increase the level or effect of red yeast rice by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. May increase creatine kinase levels and increase risk of myopathy or rhabdomyolysis; red yeast rice contains monocolin K (reportedly identical to lovastatin)

            • ribociclib

              fosamprenavir will increase the level or effect of ribociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If a strong CYP3A inhibitor must be coadministered with ribociclib, reduce the ribociclib starting dose to 400 mg/day.

            • rifabutin

              rifabutin will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • rifampin

              rifampin will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • rifapentine

              rifapentine decreases levels of fosamprenavir by increasing metabolism. Contraindicated.

            • riociguat

              fosamprenavir will increase the level or effect of riociguat by Other (see comment). Avoid or Use Alternate Drug. Coadministration of riociguat (an ABCG2 [BCRP] substrate) with strong ABCG2 inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if needed

            • ritonavir

              ritonavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • romidepsin

              fosamprenavir will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong 3A4 inhibitors should be avoided if possible.

            • ruxolitinib

              fosamprenavir will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/L

            • ruxolitinib topical

              fosamprenavir will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/L

            • selumetinib

              fosamprenavir will increase the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.

            • silodosin

              fosamprenavir will increase the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • siponimod

              fosamprenavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

            • sirolimus

              fosamprenavir will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • sonidegib

              fosamprenavir will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sonidegib with strong CYP3A4 inhibitors.

            • St John's Wort

              St John's Wort decreases levels of fosamprenavir by increasing metabolism. Contraindicated.

            • suvorexant

              fosamprenavir increases levels of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Suvorexant not recommended with use of strong CYP3A4 inhibitors.

            • tadalafil

              fosamprenavir will increase the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Stop tadalafil >24 hours prior to protease inhibitor (PI) initiation, restart 7 days after PI initiation at 20 mg once daily, and increase to 40 mg once daily based on tolerability.

            • tamoxifen

              fosamprenavir, tamoxifen. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP3A4 inhibition decreases metabolism of tamoxifen to N-desmethyl tamoxifen (active metabolite with similar biologic activity).

            • tamsulosin

              fosamprenavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tazemetostat

              fosamprenavir will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of tazemetostat with moderate CYP3A4 inhibitors. If coadministration is unavoidable, reduce tazemetostat current dose (see drug monograph Dosage Modifications).

            • tipranavir

              tipranavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tofacitinib

              fosamprenavir increases levels of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce tofacitinib dose to 5 mg qDay when coadministered with potent CYP3A4 inhibitors.

            • tolvaptan

              fosamprenavir will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • trabectedin

              fosamprenavir will increase the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If strong CYP3A inhibitor must be used, short-term (eg, less than 14 days), administer strong CYP3A inhibitor 1 week after trabectedin infusion, and discontinue the day prior to next trabectedin infusion

            • trazodone

              fosamprenavir increases levels of trazodone by decreasing metabolism. Avoid or Use Alternate Drug.

            • triazolam

              fosamprenavir increases levels of triazolam by decreasing metabolism. Contraindicated.

            • trimipramine

              fosamprenavir increases levels of trimipramine by decreasing metabolism. Avoid or Use Alternate Drug.

            • tucatinib

              tucatinib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

            • vemurafenib

              fosamprenavir increases levels of vemurafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • vilazodone

              fosamprenavir increases levels of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If intolerable adverse effects occur when coadministered with moderate CYP3A4 inhibitors, reduce daily dose to 20 mg.

            • vorapaxar

              fosamprenavir increases levels of vorapaxar by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • voriconazole

              voriconazole, fosamprenavir. Either increases levels of the other by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • voxelotor

              voxelotor will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

            Monitor Closely (276)

            • abacavir

              fosamprenavir and abacavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • abemaciclib

              fosamprenavir will increase the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A4 inhibitors increase plasma levels of abemaciclib and its metabolites. Abemaciclib dose reduction required. If a strong CYP3A4 inhibitor is discontinued, increase abemaciclib to the dose prior to initiating the strong inhibitor.

            • acarbose

              fosamprenavir decreases effects of acarbose by pharmacodynamic antagonism. Use Caution/Monitor. New onset or exacerbation of diabetes mellitus and hyperglycemia have been reported with protease inhibitors.

            • albiglutide

              fosamprenavir decreases effects of albiglutide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • almotriptan

              fosamprenavir will increase the level or effect of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • alprazolam

              fosamprenavir will increase the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • aluminum hydroxide

              aluminum hydroxide will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • amitriptyline

              fosamprenavir will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • amlodipine

              fosamprenavir will increase the level or effect of amlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • amobarbital

              amobarbital will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • apalutamide

              fosamprenavir will increase the level or effect of apalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of apalutamide with strong CYP3A4 or CYP2C8 inhibitors does not require initial dosage modification; however, dose reduction may be needed based on tolerability.

            • aprepitant

              aprepitant will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • aripiprazole

              fosamprenavir will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • armodafinil

              armodafinil will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • artemether/lumefantrine

              fosamprenavir will increase the level or effect of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • atazanavir

              atazanavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              atazanavir and fosamprenavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • atogepant

              fosamprenavir will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • bazedoxifene/conjugated estrogens

              fosamprenavir will increase the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • belzutifan

              belzutifan will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information.

            • benzhydrocodone/acetaminophen

              fosamprenavir will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with strong CYP3A4 inhibitors may increase hydrocodone (benzhydrocodone is prodrug of hydrocodone) plasma concentrations and can result in potentially fatal respiratory depression.

            • bexarotene

              fosamprenavir will increase the level or effect of bexarotene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • bortezomib

              fosamprenavir will increase the level or effect of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • bosutinib

              bosutinib increases levels of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • brentuximab vedotin

              fosamprenavir increases levels of brentuximab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor patients for adverse reactions. .

            • brexpiprazole

              fosamprenavir will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.

            • bromocriptine

              fosamprenavir increases levels of bromocriptine by decreasing metabolism. Use Caution/Monitor. Increased levels possibly due to CYP3A4 inhibition.

            • budesonide

              fosamprenavir will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              budesonide will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • buprenorphine

              fosamprenavir increases levels of buprenorphine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. .

            • buprenorphine buccal

              fosamprenavir increases levels of buprenorphine buccal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. .

            • buprenorphine subdermal implant

              fosamprenavir will increase the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inhibitors for signs and symptoms of overmedication. If the dose of the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inhibitor is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for withdrawal.

            • buprenorphine, long-acting injection

              fosamprenavir will increase the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inhibitors should be monitored to ensure buprenorphine plasma levels are adequate. Within 2 weeks, if signs and symptoms of buprenorphine toxicity or overdose occur and the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.

            • buspirone

              fosamprenavir will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • butabarbital

              butabarbital will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • butalbital

              butalbital will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cabazitaxel

              fosamprenavir increases levels of cabazitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Avoid coadministration.

            • calcifediol

              fosamprenavir, calcifediol. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. CYP450 inhibitors may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1). This may alter serum levels of calcifediol and decrease the conversion of calcifediol to calcitriol. Dose adjustment of calcifediol may be required, and serum 25­hydroxyvitamin D, intact PTH, and serum calcium concentrations should be closely monitored when initiating or discontinuing a strong CYP3A4 inhibitor.

            • calcium carbonate

              calcium carbonate will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • cannabidiol

              fosamprenavir will increase the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a strong CYP3A4 inhibitor.

            • carbamazepine

              fosamprenavir will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor plasma levels when used concomitantly

            • cariprazine

              fosamprenavir will increase the level or effect of cariprazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with strong CYP3A4 inhibitors requires cariprazine dose reduction. See Dosage Modification section in drug monograph.

            • cenobamate

              cenobamate will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

            • chlordiazepoxide

              fosamprenavir increases levels of chlordiazepoxide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Consider lowering benzodiazepine dose.

            • chlorpropamide

              fosamprenavir, chlorpropamide. Other (see comment). Use Caution/Monitor. Comment: Fosamprenavir may increase or decrease levels of chlorpropamide. Use alternatives if available. Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • ciclesonide inhaled

              fosamprenavir increases levels of ciclesonide inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of Cushing's syndrome or adrenal suppression.

            • cilostazol

              fosamprenavir will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cimetidine

              cimetidine will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • cinacalcet

              fosamprenavir will increase the level or effect of cinacalcet by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • citalopram

              fosamprenavir increases levels of citalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • clomipramine

              fosamprenavir will increase the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • clonazepam

              fosamprenavir increases levels of clonazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Consider lowering benzodiazepine dose.

            • clopidogrel

              fosamprenavir will decrease the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Inhibition of CYP3A4 will reduce clopidogrel bioactivation

            • clorazepate

              fosamprenavir increases levels of clorazepate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

            • clozapine

              fosamprenavir will increase the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • conivaptan

              conivaptan will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • conjugated estrogens

              fosamprenavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • conjugated estrogens, vaginal

              fosamprenavir will increase the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cortisone

              fosamprenavir will increase the level or effect of cortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              cortisone will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • crizotinib

              fosamprenavir increases levels of crizotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Concomitant use of strong CYP3A inhibitors should be avoided. .

              crizotinib increases levels of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • crofelemer

              crofelemer increases levels of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

            • cyclosporine

              cyclosporine will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir will increase the level or effect of cyclosporine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dabrafenib

              dabrafenib will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • daridorexant

              fosamprenavir will increase the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Daridorexant dose should not exceed 25 mg per night when coadministered with moderate CYP3A4 inhibitors.

            • darifenacin

              darifenacin will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • darunavir

              darunavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              darunavir and fosamprenavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • dasatinib

              dasatinib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • deferasirox

              deferasirox will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • deflazacort

              fosamprenavir will increase the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease deflazacort dose to one-third of the recommended dose if coadministered with moderate or strong CYP3A4 inhibitors.

            • desipramine

              fosamprenavir will increase the level or effect of desipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • desvenlafaxine

              fosamprenavir increases levels of desvenlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • dexamethasone

              fosamprenavir will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              dexamethasone will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dexlansoprazole

              dexlansoprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • DHEA, herbal

              DHEA, herbal will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • diazepam

              fosamprenavir increases levels of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available.

            • diazepam intranasal

              fosamprenavir will increase the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.

            • diazoxide

              fosamprenavir increases effects of diazoxide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • didanosine

              didanosine will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Applies to didanosine chewable tablets and powder for oral solution;dminister 2 hr before or several hours after didanosine oral solution or chewable tablet administration

            • dienogest/estradiol valerate

              fosamprenavir will increase the level or effect of dienogest/estradiol valerate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Significant changes (increase or decrease) in plasma levels of estrogen and progestin have been seen when HIV protease inhibitors are administered. Monitor for potential adverse effects such as nausea, irregular uterine bleeding, breast tenderness and headache.

            • diltiazem

              diltiazem will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Protease Inhibitors may decrease metabolism of diltiazem. Increased serum concentrations of diltiazem may increase risk of AV nodal blockade.

              fosamprenavir will increase the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dofetilide

              fosamprenavir increases levels of dofetilide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.

            • doravirine

              fosamprenavir will increase the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of doravirine and CYP3A4 inhibitors may increase plasma concentrations and toxicities of doravirine.

            • doxorubicin

              fosamprenavir will increase the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • doxorubicin liposomal

              fosamprenavir will increase the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dronabinol

              fosamprenavir will increase the level or effect of dronabinol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dronabinol is a CYP3A4 substrate.

            • dronedarone

              dronedarone will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • efavirenz

              efavirenz will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir and efavirenz both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • elagolix

              elagolix decreases levels of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

            • eletriptan

              fosamprenavir will increase the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • eliglustat

              eliglustat increases levels of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.

            • elvitegravir

              fosamprenavir, elvitegravir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Elvitegravir is a CYP3A4 substrate; unknown if fosamprenavir will elevate levels; there are no data available to alter current dosing recommendations; recommended dose is elvitegravir 150 mg PO once daily with fosamprenavir/ritonavir 700/100 mg PO BID.

            • emtricitabine

              fosamprenavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • encorafenib

              encorafenib, fosamprenavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

            • enfuvirtide

              fosamprenavir and enfuvirtide both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • erlotinib

              fosamprenavir will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • escitalopram

              fosamprenavir increases levels of escitalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of serotonin syndrome.

            • eslicarbazepine acetate

              eslicarbazepine acetate will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • esomeprazole

              esomeprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • estradiol

              fosamprenavir will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estradiol vaginal

              fosamprenavir will increase the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with CYP3A4 inhibitors may increase plasma concentrations of estrogens and toxicities.

            • estrogens conjugated synthetic

              fosamprenavir will increase the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estrogens esterified

              fosamprenavir will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estropipate

              fosamprenavir will increase the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • eszopiclone

              fosamprenavir increases levels of eszopiclone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce eszopiclone starting dose to 1 mg/day.

            • ethosuximide

              fosamprenavir increases levels of ethosuximide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • etonogestrel

              fosamprenavir will increase the level or effect of etonogestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • etoposide

              fosamprenavir will increase the level or effect of etoposide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • etravirine

              fosamprenavir will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • exenatide injectable solution

              fosamprenavir decreases effects of exenatide injectable solution by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • exenatide injectable suspension

              fosamprenavir decreases effects of exenatide injectable suspension by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors.

            • famotidine

              famotidine will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • fedratinib

              fedratinib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

            • felodipine

              fosamprenavir will increase the level or effect of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fesoterodine

              fosamprenavir will increase the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • finerenone

              fosamprenavir will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or moderate CYP3A4 inhibitors. Adjust finererone dosage as needed.

            • fluconazole

              fluconazole will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fludrocortisone

              fosamprenavir will increase the level or effect of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fludrocortisone will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • flurazepam

              fosamprenavir increases levels of flurazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

            • fluticasone furoate

              fosamprenavir will increase the level or effect of fluticasone furoate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposure

            • fluticasone inhaled

              fosamprenavir will increase the level or effect of fluticasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposure

            • fluvoxamine

              fluvoxamine will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fosphenytoin

              fosphenytoin, fosamprenavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of fosphenytoin and fosamprenavir alone may decrease the concentration of amprenavir, the active metabolite; when given with the combination of fosamprenavir and ritonavir an increased concentration of amprenavir is observed.

            • fostamatinib

              fosamprenavir will increase the level or effect of fostamatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A4 inhibitors may increase exposure to R406 (fostamatinib major active metabolite). Monitor for toxicities that may require fostamatinib dose reduction.

              fostamatinib will increase the level or effect of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Concomitant use of fostamatinib may increase concentrations of P-gp substrates. Monitor for toxicities of the P-gp substrate drug that may require dosage reduction when given concurrently with fostamatinib.

            • garlic

              garlic decreases levels of fosamprenavir by unknown mechanism. Use Caution/Monitor.

            • gefitinib

              fosamprenavir increases levels of gefitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of strong CYP3A4 inhibitors may increase risk for gefitinib adverse effects.

            • glecaprevir/pibrentasvir

              fosamprenavir will increase the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • glimepiride

              fosamprenavir decreases effects of glimepiride by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • glipizide

              fosamprenavir, glipizide. Other (see comment). Use Caution/Monitor. Comment: Fosamprenavir may increase or decrease levels of glipizide. Use alternatives if available. Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • glyburide

              fosamprenavir decreases effects of glyburide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • grapefruit

              grapefruit will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • griseofulvin

              griseofulvin will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • guanfacine

              fosamprenavir will increase the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations. FDA-approved labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the recommended dose. Specific recommendations for immediate-release (IR) guanfacine are not available.

            • hydrocodone

              fosamprenavir will increase the level or effect of hydrocodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with CYP3A4 inhibitors may increase hydrocodone plasma concentrations and can result in potentially fatal respiratory depression

            • hydrocortisone

              fosamprenavir will increase the level or effect of hydrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              hydrocortisone will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • hydroxyprogesterone caproate

              fosamprenavir will increase the level or effect of hydroxyprogesterone caproate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ibuprofen/famotidine

              ibuprofen/famotidine will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • ifosfamide

              fosamprenavir will decrease the level or effect of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inhibitors may decrease the metabolism of ifosfamide to its active alkylating metabolites, perhaps decreasing the effectiveness of ifosfamide treatment.

            • iloperidone

              fosamprenavir will increase the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              iloperidone increases levels of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

            • imipramine

              fosamprenavir will increase the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • indinavir

              fosamprenavir will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              indinavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir and indinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • insulin aspart

              fosamprenavir decreases effects of insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • insulin degludec

              fosamprenavir decreases effects of insulin degludec by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

            • insulin degludec/insulin aspart

              fosamprenavir decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

            • insulin detemir

              fosamprenavir decreases effects of insulin detemir by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • insulin glargine

              fosamprenavir decreases effects of insulin glargine by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • insulin glulisine

              fosamprenavir decreases effects of insulin glulisine by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • insulin inhaled

              fosamprenavir decreases effects of insulin inhaled by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

            • insulin lispro

              fosamprenavir decreases effects of insulin lispro by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • insulin NPH

              fosamprenavir decreases effects of insulin NPH by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • insulin regular human

              fosamprenavir decreases effects of insulin regular human by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • isavuconazonium sulfate

              fosamprenavir will decrease the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • isoniazid

              isoniazid will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • istradefylline

              istradefylline will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

            • ivacaftor

              fosamprenavir will increase the level or effect of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce ivacaftor dose if coadministered with moderate CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.

              ivacaftor increases levels of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.

            • ixabepilone

              fosamprenavir will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ketamine

              fosamprenavir will decrease the level or effect of ketamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lacosamide

              fosamprenavir increases levels of lacosamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider decreasing lacosamide dose when coadministered with strong CYP3A4 inhibitors.

            • lamivudine

              fosamprenavir and lamivudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • lansoprazole

              lansoprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • lapatinib

              fosamprenavir will increase the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lefamulin

              fosamprenavir will increase the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for adverse effects if lefamulin is coadministered with moderate CYP3A inhibitors.

            • levamlodipine

              fosamprenavir will increase the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with moderate and strong CYP3A inhibitors results in increased systemic exposure to amlodipine and may require dose reduction. Monitor for symptoms of hypotension and edema when amlodipine is coadministered with CYP3A inhibitors to determine the need for dose adjustment.

            • levomilnacipran

              fosamprenavir will increase the level or effect of levomilnacipran by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed 80 mg/day of levomilnacipran when coadministered with strong CYP3A4 inhibitors

            • levonorgestrel oral/ethinylestradiol/ferrous bisglycinate

              fosamprenavir will increase the level or effect of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with CYP3A4 inhibitors may increase the plasma hormone concentrations. Use of a nonhormonal contraceptive is recommended.

            • linagliptin

              fosamprenavir decreases effects of linagliptin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • liraglutide

              fosamprenavir decreases effects of liraglutide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • lomitapide

              lomitapide increases levels of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

            • lopinavir

              fosamprenavir will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • loratadine

              fosamprenavir will increase the level or effect of loratadine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lumacaftor/ivacaftor

              fosamprenavir increases levels of lumacaftor/ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A inhibitors do not impact lumacaftor exposure, but increased ivacaftor exposure by 4.3-fold. Due to the induction effect of lumacaftor on CYP3A, at steady-state the net exposure of ivacaftor is not expected to exceed that when given in the absence of lumacaftor at a dose of 150 mg q12hr (the approved dose of ivacaftor monotherapy). Therefore, no dose adjustment is necessary when CYP3A inhibitors are initiated in patients currently taking lumacaftor/ivacaftor. However, when initiating lumacaftor/ivacaftor in patients taking strong CYP3A inhibitors, reduce the dose to 1 tablet daily (lumacaftor 200 mg/ivacaftor 125 mg total daily dose) for the first week of treatment to allow for the steady-state induction effect of lumacaftor. Following this period, continue with the recommended daily dose. No dose adjustment is required for moderate or weak CYP3A4 inhibitors.

            • lumefantrine

              fosamprenavir will increase the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • maraviroc

              fosamprenavir will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Decrease maraviroc dose to 150 mg BID when coadministered with strong CYP3A4 inhibitors; maraviroc decreases the conversion of fosamprenavir to the active amprenavir moiety

            • marijuana

              marijuana will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • medroxyprogesterone

              fosamprenavir will increase the level or effect of medroxyprogesterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • meperidine

              fosamprenavir increases levels of meperidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • mestranol

              fosamprenavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir, mestranol. unspecified interaction mechanism. Use Caution/Monitor. Variable effect on estradiol. Use non-hormonal contraception.

            • metformin

              fosamprenavir decreases effects of metformin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • methadone

              fosamprenavir will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • methylprednisolone

              fosamprenavir will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              methylprednisolone will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • metronidazole

              metronidazole will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • miconazole vaginal

              miconazole vaginal will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • midazolam

              fosamprenavir will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • mifepristone

              fosamprenavir, mifepristone. Either increases levels of the other by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Do not exceed mifepristone 300 mg/day for Cushing syndrome when coadministered with strong CYP3A4 inhibitors.

            • miglitol

              fosamprenavir decreases effects of miglitol by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • mipomersen

              mipomersen, fosamprenavir. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

            • mirtazapine

              fosamprenavir increases levels of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • mitotane

              mitotane decreases levels of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

            • modafinil

              modafinil will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • mometasone inhaled

              fosamprenavir increases levels of mometasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of Cushing's syndrome or adrenal suppression.

            • nafcillin

              nafcillin will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • naldemedine

              fosamprenavir increases levels of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with strong or moderate CYP3A4 inhibitors.

            • nateglinide

              fosamprenavir decreases effects of nateglinide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • nelfinavir

              fosamprenavir will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              nelfinavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir and nelfinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • netupitant/palonosetron

              fosamprenavir will increase the level or effect of netupitant/palonosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Netupitant is mainly metabolized by CYP3A4; no dosage adjustment is required

            • nevirapine

              nevirapine will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir and nevirapine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • nicardipine

              fosamprenavir will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nifedipine

              nifedipine will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nilotinib

              fosamprenavir will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nisoldipine

              fosamprenavir will increase the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nizatidine

              nizatidine will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • norethindrone

              fosamprenavir, norethindrone. unspecified interaction mechanism. Use Caution/Monitor. Variable effect on norethindrone. Use non-hormonal contraception.

            • oliceridine

              fosamprenavir will increase the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.

            • omeprazole

              omeprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • ondansetron

              fosamprenavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

            • orlistat

              orlistat will decrease the level or effect of fosamprenavir by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Loss of virological control reported in HIV-infected patients taking orlistat concomitantly. Exact mechanism is unclear, but may include a drug-drug interaction that inhibits systemic absorption of the antiretroviral drug. Monitor HIV RNA levels frequently and if increased HIV viral load confirmed, discontinue orlistat.

            • ospemifene

              fosamprenavir increases levels of ospemifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • oxcarbazepine

              oxcarbazepine will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • panobinostat

              fosamprenavir increases levels of panobinostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce panobinostat starting dose to 10 mg if coadministered with strong CYP3A4 inhibitors.

            • pantoprazole

              pantoprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • paricalcitol

              fosamprenavir increases levels of paricalcitol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • paroxetine

              fosamprenavir will decrease the level or effect of paroxetine by increasing elimination. Use Caution/Monitor. Monitor response to paroxetine therapy closely

            • pentobarbital

              pentobarbital will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • phenobarbital

              phenobarbital will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • phenytoin

              phenytoin, fosamprenavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of phenytoin and fosamprenavir alone may decrease the concentration of amprenavir, the active metabolite; when given with the combination of fosamprenavir and ritonavir an increased concentration of amprenavir is observed.

            • ponatinib

              ponatinib increases levels of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • posaconazole

              fosamprenavir decreases levels of posaconazole by unknown mechanism. Modify Therapy/Monitor Closely. Combination may decrease posaconazole plasma concentrations. If administered concomitantly, monitor closely for breakthrough fungal infections.

            • pramlintide

              fosamprenavir decreases effects of pramlintide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • prednisone

              fosamprenavir will increase the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              prednisone will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • primidone

              primidone will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • quetiapine

              fosamprenavir will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • quinidine

              fosamprenavir will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • quinupristin/dalfopristin

              quinupristin/dalfopristin will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rabeprazole

              rabeprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • raltegravir

              fosamprenavir will decrease the level or effect of raltegravir by unknown mechanism. Use Caution/Monitor.

            • repaglinide

              fosamprenavir will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ribociclib

              ribociclib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rifapentine

              rifapentine will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rilpivirine

              fosamprenavir increases effects of rilpivirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Rilpivirine is not expected to affect the plasma concentrations of co-administered protease inhibitors. .

            • rimegepant

              fosamprenavir will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid repeating rimegepant dose within 48 hr if coadministered with a moderate CYP3A4 inhibitor.

            • ritonavir

              fosamprenavir will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir and ritonavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • rosiglitazone

              fosamprenavir decreases effects of rosiglitazone by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • rucaparib

              rucaparib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

            • rufinamide

              rufinamide will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • saquinavir

              fosamprenavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

              saquinavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • saxagliptin

              fosamprenavir will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Limit saxagliptin dose to 2.5 mg/day when coadministered with strong CYP3A4 inhibitors

            • secobarbital

              secobarbital will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • sertraline

              fosamprenavir increases levels of sertraline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • sildenafil

              fosamprenavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • sitagliptin

              fosamprenavir decreases effects of sitagliptin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • sodium bicarbonate

              sodium bicarbonate will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • sodium citrate/citric acid

              sodium citrate/citric acid will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • sodium zirconium cyclosilicate

              sodium zirconium cyclosilicate will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Check specific recommendations for drugs that exhibit pH-dependent solubility that may affect their systemic exposure and efficacy. In general, administer drugs at least 2 hr before or after sodium zirconium cyclosilicate.

            • solifenacin

              fosamprenavir will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • stavudine

              fosamprenavir and stavudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • stiripentol

              stiripentol, fosamprenavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.

            • sufentanil SL

              fosamprenavir will increase the level or effect of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of sufentanil SL with any CYP3A4 inhibitor may increase sufentanil plasma concentration, and, thereby increase or prolonged adverse effects, including potentially fatal respiratory depression.

            • sunitinib

              fosamprenavir will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tacrolimus

              fosamprenavir will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tasimelteon

              fosamprenavir will increase the level or effect of tasimelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tazemetostat

              tazemetostat will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tecovirimat

              tecovirimat will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

            • temsirolimus

              fosamprenavir will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tenofovir DF

              fosamprenavir and tenofovir DF both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • tezacaftor

              fosamprenavir will increase the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust tezacaftor dosage regimen if coadministered with a strong CYP3A inhibitor.

            • theophylline

              fosamprenavir will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ticagrelor

              fosamprenavir increases levels of ticagrelor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Ticagrelor is metabolized by CYP3A4/5. Avoid use with strong CYP3A inhibitors.

            • tinidazole

              fosamprenavir will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tipranavir

              fosamprenavir will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosamprenavir and tipranavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • tolazamide

              fosamprenavir, tolazamide. Other (see comment). Use Caution/Monitor. Comment: Fosamprenavir may increase or decrease levels of tolazamide. Use alternatives if available. Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • tolbutamide

              fosamprenavir, tolbutamide. Other (see comment). Use Caution/Monitor. Comment: Fosamprenavir may increase or decrease levels of tolbutamide. Use alternatives if available. Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

            • tolterodine

              fosamprenavir will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • topiramate

              topiramate will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • toremifene

              fosamprenavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • trazodone

              fosamprenavir will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • triamcinolone acetonide injectable suspension

              fosamprenavir will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • triazolam

              fosamprenavir will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • umeclidinium bromide/vilanterol inhaled

              fosamprenavir will increase the level or effect of umeclidinium bromide/vilanterol inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vilanterol is a CYP3A4 substrate; coadministration with potent CYP3A4 inhibitors may increase systemic exposure

            • valbenazine

              fosamprenavir will increase the level or effect of valbenazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce valbenazine dose to 40 mg once daily when coadministered with a strong CYP3A4 inhibitor.

            • vardenafil

              fosamprenavir will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • vemurafenib

              vemurafenib increases levels of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • verapamil

              fosamprenavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • vilanterol/fluticasone furoate inhaled

              fosamprenavir will increase the level or effect of vilanterol/fluticasone furoate inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Fluticasone furoate and vilanterol are both CYP3A4 substrates; coadministration with potent CYP3A4 inhibitors may increase systemic exposure

            • voclosporin

              fosamprenavir will increase the level or effect of voclosporin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce voclosporin daily dosage to 15.8 mg PO in AM and 7.9 mg PO in PM.

            • warfarin

              fosamprenavir will increase the level or effect of warfarin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • zafirlukast

              zafirlukast will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • zanubrutinib

              fosamprenavir will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib dose when coadministered with a moderate CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib. See zanubrutinib Dosage Modifications for precise recommendation.

            • zidovudine

              fosamprenavir and zidovudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

            • zileuton

              fosamprenavir increases levels of zileuton by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            Minor (44)

            • alfentanil

              fosamprenavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • aliskiren

              fosamprenavir will increase the level or effect of aliskiren by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • alosetron

              fosamprenavir will increase the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • armodafinil

              fosamprenavir will increase the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • atazanavir

              fosamprenavir will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • bosentan

              fosamprenavir will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • cevimeline

              fosamprenavir will increase the level or effect of cevimeline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • clarithromycin

              fosamprenavir will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • dapsone

              fosamprenavir will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • disopyramide

              fosamprenavir will increase the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • docetaxel

              fosamprenavir will increase the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • donepezil

              fosamprenavir will increase the level or effect of donepezil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • dutasteride

              fosamprenavir will increase the level or effect of dutasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • efavirenz

              fosamprenavir will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • eplerenone

              fosamprenavir will increase the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • eucalyptus

              fosamprenavir will increase the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • finasteride

              fosamprenavir will increase the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • galantamine

              fosamprenavir will increase the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • imatinib

              fosamprenavir will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • isradipine

              fosamprenavir will increase the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ixazomib

              fosamprenavir, ixazomib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. In clinical trials, coadministration of ixazomib with strong CYP3A inhibitors did not result in a clinically meaningful change in the systemic exposure of ixazomib.

            • ketoconazole

              fosamprenavir will increase the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • montelukast

              fosamprenavir will increase the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nifedipine

              fosamprenavir will increase the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nimodipine

              fosamprenavir will increase the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nitrendipine

              fosamprenavir will increase the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • oxybutynin

              fosamprenavir will increase the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • paclitaxel

              fosamprenavir will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • paclitaxel protein bound

              fosamprenavir will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • parecoxib

              fosamprenavir will increase the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • pimozide

              fosamprenavir will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • pioglitazone

              fosamprenavir will increase the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • propafenone

              fosamprenavir will increase the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • quinine

              fosamprenavir will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ramelteon

              fosamprenavir will increase the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • sufentanil

              fosamprenavir will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vinblastine

              fosamprenavir will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vincristine

              fosamprenavir will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vincristine liposomal

              fosamprenavir will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vinorelbine

              fosamprenavir will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zaleplon

              fosamprenavir will increase the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ziprasidone

              fosamprenavir will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zolpidem

              fosamprenavir will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zonisamide

              fosamprenavir will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            Previous
            Next:

            Adverse Effects

            >10%

            Nausea (30-50%)

            Rash (16-20%)

            Fatigue (11-15%)

            Diarrhea (5-13%)

            Increased triglycerides (11%)

            1-10%

            Increased serum lipase, ALT, AST (5-10%) in pts. treatment with concomitant ritonavir

            Vomiting (2-6%)

            Headache (2-4%)

            Pruritus (7-8%)

            Nausea (3-7%)

            Abdominal pain (≤ 2%)

            Increased hepatic transaminases (4-8%)

            <1%

            Stevens-Johnson syndrome

            Angioedema

            Myocardial infarction

            QT prolongation

            Nephrolithiasis

            Hypercholesterolemia

            Frequency Not Defined

            Spontaenous bleeding

            Acute hemolytic anemia

            Immune reconstitution syndrome

            Diabetes Mellitus

            Increase of body fat

            Previous
            Next:

            Warnings

            Contraindications

            Hypersensitivity (eg, Stevens-Johnson syndrome) to fosamprenavir, amprenavir, or other component

            Concomitant use of drugs that depend heavily on CYP3A4 for clearance; metabolite amprenavir is a strong CYP3A4 inhibitor; use with ritonavir another strong CYP3A4 inhibitor may have additive inhibitory effects; check Drug Interactions

            Drugs that are contraindicated with fosamprenavir (with or without ritonavir) include lipid modifying agents (eg, lomitapide, lovastatin, simvastatin), alpha1-adrenoreptor agonists (eg, alfuzosin), antiarrhythmics (flecainide, propafenone), rifampin, ergot derivatives (dihydroergotamine, ergonovine, ergotamine, methylergonovine), cisapride, St. John’s wort, lurasidone, pimozide, sildenafil (when used for PAH), midazolam, and triazolam

            Cautions

            New onset DM, exacerbation of pre-existing DM & hyperglycemia reported with unknown frequency/unknown causal relationship

            Sulfonamide allergy

            Monitor labs prior to and during treatment with Hepatitis B or C, or elevated transaminases

            Few reports of spontaneous bleeding in patients. with Hemophilia A and B

            During initial treatment, inflammatory response to indolent or residual opportunistic infections may occur and require treatment

            Fat redistribution with "cushingoid appearance" and "buffalo hump" may occur

            Increased risk for myocardial infarction (thought to be caused by protease inhibitors increasing risk of hyperlipidemia)

            Monitor triglycerides and cholesterol levels before initiating, then periodically; initiate clinical management of lipid disorders as required

            Combination treatment with ritonavir may lead to increased triglyceride level

            Unknown effect on activity of subsequently administered protease inhibitors

            Risk of immune reconstitution syndrome if used in combination with other antiretroviral drugs; autoimmune disorders (eg Graves disease, polymyositis, and Guillain-Barré syndrome) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable, and can occur many months after initiation of treatment

            Vomiting more common in children

            Cases of nephrolithiasis reported with fosamprenavir

            Acute hemolytic anemia reported with amprenavir

            Discontinue therapy if severe skin reactions including Stevens-Johnson syndrome occur

            Previous
            Next:

            Pregnancy & Lactation

            Pregnancy

            Pregnancy Registry: to monitor maternal-fetal outcomes of pregnant women exposed to antiretroviral medications call 1-800-258-4263 or visit www.APRegistry.com

            There are insufficient prospective pregnancy data from Antiretroviral Pregnancy Registry (APR) to adequately assess risk of adverse developmental outcomes; fosamprenavir use during pregnancy has been evaluated in a limited number of women as reported by the APR; available data from the APR show 2 birth defects in 109 first trimester exposures and 2 birth defects in 36 second and third trimester exposures compared with background rate for major birth defects of 2.7% in a U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP)

            Limited data are available for use in pregnancy; fosamprenavir 700 mg BID with ritonavir 100 mg BID should only be considered in pregnant patients who are already on a stable fosamprenavir/ritonavir regimen prior to pregnancy, and who are virologically suppressed (HIV-1 RNA <50 copies/mL)

            Contraception

            • Fosamprenavir may reduce the efficacy of combined hormonal contraceptives; advise patients to use an effective alternative contraceptive method or an additional barrier method of contraception

            Lactation

            There is no information available on presence of amprenavir in human milk, the effects of the drug on breastfed infant, or effects of drug on milk production

            The CDC recommends that HIV1-infected mothers in the United States not breastfeed their infants to avoid risking postnatal transmission of HIV-1 infection

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

            Previous
            Next:

            Pharmacology

            Mechanism of Action

            Prodrug converted to amprenavir (protease inhibitor) by cellular phosphatases in vivo; 700 mg fosamprenavir equivalent to 600 mg amprenavir

            Binds to active site of HIV-1 protease and thereby prevents processing of viral Gag and Gag-Pol polyprotein precursors, resulting in the formation of immature noninfectious viral particle

            Pharmacokinetics

            Half-Life: 7.7 hr

            Peak Plasma Time: 1.5-4 hr

            Protein Bound: 90%

            Absorption: 63%

            Metabolism: hepatic CYP3A4

            Enzymes inhibited: CYP3A4

            Metabolite: Amprenavir

            Excretion: Feces (75%); urine (15%)

            Previous
            Next:

            Administration

            Oral Administration

            Tablet: Take with meals if boosted with ritonavir; take without regard to meals if not boosted with ritonavir

            Oral suspension: Adults should take without food; children should take with food

            If vomiting occurs within 30 min, repeat dose

            Adult dosage tablet use in children

            • ≥47 kg: May use adult dosage with tabs (without ritonavir)
            • ≥39 kg: May use adult dosage with tabs (with ritonavir) q12hr
            Previous
            Next:

            Images

            BRAND FORM. UNIT PRICE PILL IMAGE
            Lexiva oral
            -
            50 mg/mL suspension
            Lexiva oral
            -
            700 mg tablet

            Copyright © 2010 First DataBank, Inc.

            Previous
            Next:

            Patient Handout

            Patient Education
            fosamprenavir oral

            FOSAMPRENAVIR - ORAL

            (fos-am-PREN-uh-veer)

            COMMON BRAND NAME(S): Lexiva

            USES: This drug is used with other HIV medications to help control HIV infection. It helps to decrease the amount of HIV in your body so your immune system can work better. This lowers your chance of getting HIV complications (such as new infections, cancer) and improves your quality of life.Fosamprenavir belongs to a class of drugs known as protease inhibitors. It may be given with ritonavir, another protease inhibitor, to increase ("boost") the levels of fosamprenavir. This helps fosamprenavir work better.Fosamprenavir is not a cure for HIV infection. To decrease your risk of spreading HIV disease to others, continue to take all HIV medications exactly as prescribed by your doctor. Use an effective barrier method (latex or polyurethane condoms/dental dams) during sexual activity as directed by your doctor. Do not share personal items (such as needles/syringes, toothbrushes, and razors) that may have contacted blood or other body fluids. Consult your doctor or pharmacist for more details.

            HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start taking fosamprenavir and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth as directed by your doctor, usually once or twice daily.Fosamprenavir tablets may be taken with or without food.If you are taking fosamprenavir suspension, shake the bottle well before each dose. Carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose. Adults should take the suspension without food. Children should take the suspension with food. If vomiting occurs less than 30 minutes after taking a dose, repeat the dose.The dosage is based on your medical condition, response to treatment, other medications you may be taking, and if you have taken protease inhibitors to treat HIV before. For children, the dosage is also based on age and weight. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). If you are directed to take ritonavir with this medication, take them both at the same time(s).For the best effect, take this medication at evenly spaced times. To help you remember, take this medication at the same time(s) every day.It is very important to continue taking this medication (and other HIV medications) exactly as prescribed by your doctor. Do not skip any doses. Do not take more or less of this drug than prescribed or stop taking it (or other HIV medicines) even for a short time unless directed to do so by your doctor. Doing so may cause the amount of virus to increase, make the infection more difficult to treat (resistant), or worsen side effects.

            SIDE EFFECTS: Diarrhea, nausea, vomiting, and headache may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.As your immune system gets stronger, it can begin to fight off infections you already had, possibly causing disease symptoms to come back. You could also have symptoms if your immune system becomes overactive. This reaction may happen at any time (soon after starting HIV treatment or many months later). Get medical help right away if you have any serious symptoms, including: unexplained weight loss, severe tiredness, muscle aches/weakness that doesn't go away, headaches that are severe or don't go away, joint pain, numbness/tingling of the hands/feet/arms/legs, vision changes, signs of infection (such as fever, chills, swollen lymph nodes, trouble breathing, cough, non-healing skin sores), signs of an overactive thyroid (such as irritability, nervousness, heat intolerance, fast/pounding/irregular heartbeat, bulging eyes, unusual growth in the neck/thyroid known as a goiter), signs of a certain nerve problem known as Guillain-Barre syndrome (such as unsteadiness, loss of coordination, trouble swallowing/speaking/chewing, trouble moving your eyes), signs of liver disease (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine).Tell your doctor right away if you have any serious side effects, including: increased thirst/urination, signs of a kidney stone (such as pain in side/back/abdomen, painful urination, blood in the urine).Changes in body fat may occur while you are taking this medication (such as increased fat in the upper back and stomach areas, decreased fat in the arms and legs). The cause and long-term effects of these changes are unknown. Discuss the risks and benefits of treatment with your doctor, as well as the possible use of exercise to reduce this side effect.Get medical help right away if you have any very serious side effects, including: signs of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating).Fosamprenavir can commonly cause a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Get medical help right away if you develop any rash.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

            PRECAUTIONS: Before taking fosamprenavir, tell your doctor or pharmacist if you are allergic to it or to amprenavir; or if you have any other allergies. This product may contain inactive ingredients (such as propylene glycol in the suspension), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver problems (including hepatitis B or C infections), kidney problems (including kidney stones), heart problems (such as coronary artery disease, heart attack), diabetes, a certain bleeding problem (hemophilia).Fosamprenavir may increase the level of cholesterol and fats (triglycerides) in your blood. HIV infection can also cause this effect. This could increase your risk for heart problems such as a heart attack. Discuss the risks and benefits of treatment with your doctor and ways to lower your risk of heart disease. Tell your doctor if you have heart problems, if you smoke, or if you have other conditions that increase your risk of heart disease such as high blood pressure, diabetes, or high cholesterol/triglyceride levels.Before having surgery, tell your doctors or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Children may be more sensitive to the side effects of this drug, especially vomiting and signs of infection (such as fever, persistent sore throat).During pregnancy, this medication should be used only when clearly needed. Treatment can lower the risk of passing HIV infection to your baby, and fosamprenavir may be part of that treatment. Discuss the risks and benefits with your doctor.It is unknown if fosamprenavir passes into breast milk. Because breast milk can transmit HIV, do not breast-feed.

            DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: certain HIV protease inhibitors (such as lopinavir, tipranavir), boceprevir, orlistat, simeprevir, telaprevir.Other medications can affect the removal of fosamprenavir from your body, which may affect how fosamprenavir works. Examples include apalutamide, etravirine, rifampin, St. John's wort, among others.Fosamprenavir can speed up or slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include alpha blockers (such as alfuzosin), certain benzodiazepines (midazolam, triazolam), delavirdine, ergot alkaloids (such as dihydroergotamine, ergotamine), fluticasone, pimozide, ranolazine, rivaroxaban, drugs to treat erectile dysfunction-ED or pulmonary hypertension (such as sildenafil, vardenafil), certain drugs to treat irregular heartbeat (such as flecainide, propafenone), certain "statin" cholesterol drugs (lovastatin, simvastatin), salmeterol, among others.This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Talk to your doctor about additional or alternative reliable forms of birth control, and use an effective barrier method (latex or polyurethane condoms/dental dams) during sexual activity to decrease the risk of spreading HIV to others. Tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your hormonal birth control is not working well.

            OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

            NOTES: Do not share this medication with others.Laboratory and/or medical tests (such as viral load, T-cell counts, liver tests, cholesterol/triglyceride levels, blood sugar levels) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

            MISSED DOSE: It is important not to miss doses of this drug. If you miss a dose by less than 4 hours, take it as soon as you remember. However, if you miss a dose by more than 4 hours, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

            STORAGE: Store the tablets in a tightly closed container at room temperature away from light and moisture.Store the suspension in a tightly closed container at room temperature or in the refrigerator. Refrigeration may improve the taste of the suspension. Do not freeze.Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

            Information last revised December 2021. Copyright(c) 2021 First Databank, Inc.

            IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

            Previous
            Next:

            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
            Additional Offers
            Email to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Email Forms to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Previous
            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.