Atazanavir dosing

Efavirenz - In treatment-naive patients who receive efavirenz and atazanavir, the recommended dose is atazanavir 300 mg with ritonavir 100 mg and efavirenz 600 mg (all once daily). 

Tenofovir disoproxil fumarate - It is recommended that atazanavir 300 mg be given with ritonavir 100 mg and tenofovir 300 mg (all as a single daily dose with food). Atazanavir without ritonavir should not be coadministered with tenofovir. 

Metabolism/Excretion- Atazanavir is extensively metabolized and eliminated primarily by the liver. Following a single 400 mg dose of atazanavir, 79% and 13% was recovered in the feces and urine, respectively. Unchanged drug accounted for approximately 20% and 7% of the administered dose in the... 

HIV-1 infection concurrent therapy withe favirenz) PO 300 mg atazanavir, 100 mg ritonavir, and 600 mg efavirenzas a single daily dose with food. 

Atazanavir PI2 400 mg daily or 300 mg daily with ritonavir 100 daily. Adjust dose in hepatic insufficiency Take with food. Separate dosing from ddl or antacids by 1 h. Separate dosing from cimetidine and other acid-reducing agents by 12 h Nausea, vomiting, diarrhea, abdominal pain, headache, peripheral neuropathy, skin rash, indirect hyperbilirubinemia, prolonged PR and/or QTC interval See footnote 4 for contraindicated medications. Also avoid indinavir, irinotecan, and omeprazole. Avoid in severe hepatic insufficiency... 

Atazanavir is an azapeptide PI with a pharmacokinetic profile that allows once-daily dosing. It should be taken with a light meal to enhance bioavailability. Atazanavir requires an acidic medium for absorption and exhibits pH-dependent aqueous solubility therefore, separation of ingestion from acid-reducing agents by at least 12 hours is recommended. Atazanavir is able to penetrate both the cerebrospinal and seminal fluids. The plasma half-life is 6-7 hours, which increases to approximately 11 hours when -administered with ritonavir. The primary route of elimination is biliary atazanavir should not be given to patients with severe hepatic insufficiency. 

Sunirinib (Sutent) [Kinase Inhibitor] Uses Advanced GI stromal tumor refractory/intolerant of imatinib advanced RCC Action Kinase inhibitor Dose Adults. 50 mg PO daily x 4 wk, followed by 2 wk holiday = 1 cycle 4- to 37.5 mg w/ CYP3A4 inhibitors (Table VI-8), to T 87.5 mg w/ CYP3A4 inducers Contra w/ atazanavir Caution [D, -] Multiple interactions require dose modification (eg, St. John s wort) Disp Caps SE -l WBC pit, bleeding, T BP, -l ejection fraction, T QT interval, pancreatitis, DVT, Sz, adrenal insuff, N/V/D, skin discoloration, oral ulcers, taste perversion, hypothyroidism Interactions Multiple interactions require dose modification (eg, St. John s wort) EMS Monitor ECG for T QT interval grapefruit juice may T adverse effects may affect potassium level (hypo-/hyperkalemia) monitor for S/Sxs of heart failure drug can 4- ejection fraction OD May cause abd pain, muscle weakness, and chills symptomatic and supportive... 

CLARITHROMYCIN, ERYTHROMYCIN PROTEASE INHIBITORS Possibly t adverse effects of macrolide with atazanavir, ritonavir (with or without lopinavir) and saquinavir Inhibition of CYP3A4- and possibly CYP1 A2-mediated metabolism. Altered transport via P-gp may be involved. Amprenavir and indinavir are also possibly t by erythromycin Consider alternatives unless there is Mycobacterium avium intracellulare infection if combined, 1 dose by 50% (75% in the presence of renal failure with a creatinine clearance of <30mL/min)... 

RIFABUTIN PROTEASE INHIBITORS t efficacy and t adverse effects of rifabutin Inhibition of CYP3A4-mediated metabolism. Nelfinavir also competitively inhibits 2C19 1 rifabutin dose by at least 50% when given with amprenavir, indinavir or nelfinavir, and by 75% with atazanavir, ritonavir (with or without lopinavir) or tipranavir... 

EFAVIRENZ ATAZANAVIR i efficacy of efavirenz t CYP3A4-mediated metabolism of efavirenz Recommended dose of atazanavir is 400 mg when given with efavirenz 600 mg. Optimal suggested treatment is this combination plus ritonavir 100 mg daily... 

DIDANOSINE (BUFFERED) PROTEASE INHIBITORS l efficacy of amprenavir, atazanavir and indinavir Absorption of these protease inhibitors may be affected by the buffered didanosine formulation, which t gastric pH Separate doses by at least 1 hour. Alternatively, consider using the enteric-coated formulation of didanosine... 

AMPRENAVIR, ATAZANAVIR H2 RECEPTOR BLOCKERS-CIMETIDINE i efficacy of amprenavir possible t levels of cimetidine L absorption of amprenavir and atazanavir. Uncertain mechanism of action on cimetidine Amprenavir separate doses by at least 1 hour. Take atazanavir at least 2 hours before or 10 hours after the H2 blocker. In both cases, monitor viral load closely... 

PROTEASE INHIBITORS PROGESTOGENS -NORETHISTERONE t adverse effects with amprenavir and atazanavir. Possibly 1 efficacy and risk of contraceptive failure with nelfinavir and ritonavir (with or without lopinavir) Uncertain Advise patients to use additional contraception for the period of intake and for 1 month after stopping coadministration with these drugs. Barrier methods are necessary to prevent transmission of infection from patients with HIV. Watch for early features of toxicity of amprenavir and atazanavir, and adjust the dose accordingly... 

NORETHISTERONE ANTIVIRALS - PROTEASE INHIBITORS t adverse effects with amprenavir and atazanavir Uncertain Watch for early features of toxicity of amprenavir and atazanavir, and adjust the dose accordingly... 

Although tenofovir is not known to induce CYPs, it has been reported to reduce the atazanavir AUC by approximately 26%. In addition, low-dose ritonavir (100 mg twice daily) increases the tenofovir AUC by 34%, and atazanavir increases the tenofovir AUC by 25%. The mechanism of these interactions is unknown. 

Atazanavir Atazanavir is a peptide protease inhibitor that is active against both HlV-1 and HlV-2. Absorption is increased by food and it is recommended that the drug be administered with a meal. Absorption may be pH dependent, because proton pump inhibitors substantially reduce drug concentration after oral dosing. Like indinavir, atazanavir frequently causes unconjugated hyperbilirubinemia. The drug may be less likely than other HIV protease inhibitors to cause lipodystrophy. 

Atazanavir is dosed orally onoe daily, thus reducing pill burden, and it appears to have minimal impact on lipid parameters but does increase total bilirubin. The drug is well absorbed when administered orally... 

One report deseribes 3 HIV-positive patients who experienced increased buprenorphine adverse effeets (e.g. daytime sleepiness, dizziness, and reduced mental function) within about 2 days of starting to take atazanavir boosted by low-dose ritonavir. When the dose of buprenorphine was reduced there was a reduction in sedative symptoms within a week. ... 

The AUC of erlotinib has been found to be increased by 66% when given with ketoconazole 200 mg twice daily for 5 days. The manufacturers advise caution with concurrent use, and recommend that the dose of erlotinib should be reduced if severe adverse reactions occur when given with strong CYP3A4 inhibitors. They specifically name atazanavir, clarithromycin, erythromycin, grapefruit and grapefruit juice, indinavir, itraconazole, ketoconazole, nefazodone, neltinavir, ritonavir, saquinavir, telithromycin, troleandomycin and voriconazole. ... 

Atazanavir, atazanavir/ritonavir, lopinavir/ritonavir and saquinavir markedly increased the AUC of maraviroc by about three to fivefold in healthy subjects. Ritonavir-boosted saquinavir had an even greater effect (alraut tenfold). In contrast, tiprana-vir/ritonavir had no effect. Ketoconazole caused a fivefold increase. The manufacturer su ests that the dose of maraviroc should be halved when used with protease inhibitors. 

Atazanavir 400 mg daily inereased the AUC and maximum level of maraviroe by 257% and 109%, respeetively. Atazanavir/ritonavir 300/100 mg inereased the AUC of maraviroe by almost fivefold. In a study in HIV-positive patients, the AUC of a single 300-mg oral dose of... 

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