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Background: We studied the effect of pregnancy on atazanavir pharmacokinetics in the presence and absence of tenofovir., Methods: This was a non-randomized, open-label, multicentre Phase IV study in HIV-infected pregnant women recruited from European HIV treatment centres. HIV-infected pregnant women treated with boosted atazanavir (300/100 mg or 400/100 mg atazanavir/ritonavir) as part of their combination antiretroviral therapy (cART) were included in the study. 24 h pharmacokinetic curves were recorded in the third trimester and postpartum. Collection of a cord blood and maternal sample at delivery was optional., Results: 31 patients were included in the analysis, 21/31 patients used tenofovir as part of cART. Median (range) gestational age at delivery was 39 weeks (36-42). Approaching delivery 81% (25 patients) had an HIV viral load <50 copies/ml, all <1,000 copies/ml. Least squares means ratios (90% CI) of atazanavir pharmacokinetic parameters third trimester/postpartum were: 0.66 (0.57, 0.75) for AUC0-24h, 0.70 (0.61, 0.80) for Cmax and 0.59 (0.48, 0.72) for C24h. No statistical difference in pharmacokinetic parameters was found between patients using tenofovir versus no tenofovir. None of the patients showed atazanavir concentrations <0.15 mg/l (target for treatment-naive patients). One baby had a congenital abnormality, which was not likely to be related to atazanavir/ritonavir use. None of the children were HIV-infected., Conclusions: Despite 34% lower atazanavir exposure during pregnancy, atazanavir/ritonavir 300/100 mg once daily generates effective concentrations for protease inhibitor (PI)-naive patients, even if co-administered with tenofovir. For treatment-experienced patients (with relevant PI resistance mutations) therapeutic drug monitoring of atazanavir should be considered to adapt the atazanavir/ritonavir dose on an individual basis.
 ClinicalTrials.gov number NCT00825929.

Background: In inflammation and infection, cytochrome P450 (CYP) enzyme activities are down-regulated. Information on possible discrepancies in activities of CYP enzymes and drug transporters between HIV-infected patients and healthy people is limited., Methods: We used midazolam, dextromethorphan and digoxin as in vivo phenotyping probes for CYP3A (CYP3A4/5), CYP2D6 and P-glycoprotein activities, respectively, and compared these activities between 12 healthy Caucasian volunteers and 30 treatment-naive HIV-infected patients., Results: Among the HIV-infected patients, the overall CYP3A activity (apparent oral midazolam clearance) was approximately 50% of the activity observed in healthy volunteers (point estimate 0.490, 90% confidence interval [CI] 0.377-0.638). The CYP2D6 activity (plasma ratio area under the curve [AUC]; AUC(dextromethorphan)/AUC(dextrorphan)) was essentially unchanged (point estimate 1.289, 90% CI 0.778-2.136). P-glycoprotein activity was slightly lower in patients (digoxin maximum concentration point estimate 1.304, 90% CI 1.034-1.644)., Conclusions: The overall CYP3A activity was approximately 50% lower in HIV-infected patients than in healthy volunteers. The CYP2D6 activity was highly variable, but, on average was not different between groups, whereas a marginally lower P-glycoprotein activity was observed in treatment-naive HIV-infected patients.

Background: Pregnancy affects the pharmacokinetics of most protease inhibitors. Saquinavir, when administered in a tablet formulation, has not been studied extensively in this setting., Methods: A pharmacokinetic, prospective, multicentre trial of HIV type-1-infected pregnant women treated with saquinavir (500 mg tablets) boosted with ritonavir at a dose of 1,000/100 mg twice daily plus a nucleoside backbone was conducted. Pharmacokinetic curves were recorded for 12 h in the second trimester (week 20 +/-2), the third trimester (week 33 +/-2) and post-partum (weeks 4-6). Blood was sampled pre-dosing and at 1, 2, 3, 4, 6, 8, 10 and 12 h post-dosing. Pharmacokinetic parameters were calculated using WinNonlin software version 4.1., Results: A total of 37 women were included in the analysis. Mean (+/-sd) values for saquinavir area under the curve (AUC(0-12h)) were 23.47 h*mg/l (11.92) at week 20 (n=16), 23.65 h*mg/l (9.07) at week 33 (n=31) and 25.00 h*mg/l (11.81) post-partum (n=9). There was no significant difference in the saquinavir AUC(0-12h) when comparing the data during pregnancy and post-partum. Subtherapeutic plasma concentrations of saquinavir (defined as <0.10 mg/l) were not observed throughout the study. No major safety concerns were noted., Conclusions: Saquinavir exposure in the new tablet formulation generates adequate saquinavir concentrations throughout the course of pregnancy and is safe to use; therefore, no dose adjustment during pregnancy is needed.

Background: Lopinavir/ritonavir-containing antiretroviral therapy can cause hyperlipidaemia. However, most statins are contraindicated due to drug-drug interactions. Rosuvastatin undergoes minimal metabolism by CYP450, so no CYP450-based interaction with lopinavir/ritonavir is expected. This study explored the lipid-lowering effect of rosuvastatin and assessed the effect of lopinavir/ritonavir on the pharmacokinetics of rosuvastatin and vice versa., Methods: HIV-infected patients on lopinavir/ritonavir (viral load < 400 copies/ml) with total cholesterol (TC) > 6.2 mmol/l were treated with rosuvastatin for 12 weeks, starting on 10 mg once daily. If fasting target values (TC < 5.0 mmol/l, high-density lipoprotein-cholesterol > 1.0 mmol/l, low-density lipoprotein-cholesterol [LDL-c] < 2.6 mmol/l and triglycerides < 2.0 mmol/l) were not reached, rosuvastatin was escalated to 20 mg or 40 mg at week 4 and 8, respectively. Plasma lopinavir/ritonavir trough levels (C(min)) were determined at week 0, 4, 8 and 12 and rosuvastatin C(min), at week 4, 8 and 12., Results: Twenty-two patients completed the study. Mean reductions in TC and LDL-c from baseline to week 4 (on rosuvastatin 10 mg once a day) were 27.6% and 31.8%, respectively. Lopinavir/ritonavir concentrations were not influenced by rosuvastatin (P = 0.44 and 0.26, repeated-measures analysis). Median (interquartile range) rosuvastatin C(min) for 10 mg, 20 mg and 40 mg once daily were 0.97 (0.70-1.5), 2.5 (1.3-3.3) and 5.5 (3.3-8.8) ng/ml, respectively., Conclusions: Rosuvastatin appeared to be an effective statin in hyperlipidaemic HIV-infected patients. Lopinavir/ritonavir levels were not affected by rosuvastatin, but rosuvastatin levels unexpectedly appeared to be increased 1.6-fold compared with data from healthy volunteers. Until safety and efficacy have been confirmed in larger studies, the combination of rosuvastatin and lopinavir/ritonavir should be used with caution.