Pharmacokinetics of tenofovir during pregnancy and postpartum.

OBJECTIVES: Tenofovir disoproxil fumarate (TDF) is increasingly used in the highly active antiretroviral therapy (HAART) regimens of pregnant women, but limited data exist on the pregnancy pharmacokinetics of chronically dosed TDF. This study described tenofovir pharmacokinetics during pregnancy and postpartum. METHODS: International Maternal Pediatric and Adolescent AIDS Clinical Trials (IMPAACT) P1026s is a prospective, nonblinded pharmacokinetic study of HIV-infected pregnant women that included a cohort receiving 300 mg TDF once daily. Steady-state 24-hour pharmacokinetic profiles were measured at the second and third trimesters, postpartum, and in maternal and umbilical cord samples collected at delivery. Tenofovir was measured by liquid chromatography-mass spectrometry (LC-MS). The target area under the concentration versus time curve from time 0 to 24 h post dose (AUC) was ≥ 1.99 µg h/mL (nonpregnant historical control 10th percentile). RESULTS: The median tenofovir AUC was decreased during the second (1.9 µg h/mL) and third (2.4 µg h/mL; P = 0.005) trimesters versus postpartum (3.0 µg h/mL). Tenofovir AUC exceeded the target for two of four women (50%) in the second trimester, 27 of 37 women [73%; 95% confidence interval (CI) 56%, 86%] in the third trimester, and 27 of 32 women (84%; 95% CI 67%, 95%) postpartum (P > 0.05). Median second/third-trimester troughs were lower (39/54 ng/mL) than postpartum (61 ng/mL). Median third-trimester weight was greater for subjects below the target AUC versus those above the target (97.9 versus 74.2 kg, respectively; P = 0.006). The median ratio of cord blood to maternal concentrations was 0.88. No infants were HIV infected. CONCLUSIONS: This study found lower tenofovir AUC and troughs during pregnancy. Transplacental passage with chronic TDF use during pregnancy was high. Standard TDF doses appear to be appropriate for most HIV-infected pregnant women but therapeutic drug monitoring with dose adjustment should be considered in pregnant women with high weight (> 90 kg) or inadequate HIV RNA response.

Alteration in cytochrome P450 3A4 activity as measured by a urine cortisol assay in HIV-1-infected pregnant women and relationship to antiretroviral pharmacokinetics.

OBJECTIVES: Pregnancy results in physiological changes altering the pharmacokinetics of drugs metabolized by cytochrome P450 3A4 (CYP3A4). The urinary ratio of 6-ß hydroxycortisol to cortisol (6ßHF : F) is a marker of CYP3A4 induction. We sought to evaluate its change in antiretroviral (ARV)-treated HIV-1-infected women and to relate this change to ARV pharmacokinetics. METHODS: Women receiving various ARVs had pharmacokinetic evaluations during the third trimester of pregnancy (>30 weeks) and postpartum with determination of 6ßHF : F carried out on the same days. The Wilcoxon signed rank test was used to compare the ratio antepartum to postpartum. The relationship between the change in ratio and the change in pharmacokinetics was analysed using Kendall's tau. RESULTS: 6ßHF : F ratios were available for 107 women antepartum, with 54 having postpartum values. The ratio was higher antepartum (P=0.033) (median comparison 1.35; 95% confidence interval 1.01, 1.81). For 71 women taking a protease inhibitor (PI), the antepartum vs. postpartum 6ßHF : F comparison was marginally significant (P=0.058). When the change in the 6ßHF : F ratio was related to the change in the dose-adjusted ARV area under the plasma concentration vs. time curve (AUC) between antepartum and postpartum, the 35 subjects in the lopinavir/ritonavir (LPV/r) arms demonstrated an inverse relationship (P=0.125), albeit this correlation did not reach statistical significance. CONCLUSIONS: A 35% increase in the urinary 6ßHF : F ratio was measured during late pregnancy compared with postpartum, indicating that CYP3A induction occurs during pregnancy. The trend towards an inverse relationship between the change in the 6ßHF : F ratio and the change in the LPV AUC antepartum vs. postpartum suggests that CYP3A induction may be one mechanism behind altered LPV exposure during pregnancy.

Effect of pregnancy on emtricitabine pharmacokinetics.

OBJECTIVES: The aim of the study was to describe emtricitabine pharmacokinetics during pregnancy and postpartum. METHODS: The International Maternal Pediatric and Adolescent AIDS Clinical Trials (IMPAACT), formerly Pediatric AIDS Clinical Trials Group (PACTG), study P1026s is a prospective pharmacokinetic study of HIV-infected pregnant women taking antiretrovirals for clinical indications, including a cohort taking emtricitabine 200 mg once daily. Intensive steady-state 24-hour emtricitabine pharmacokinetic profiles were performed during the third trimester and 6-12 weeks postpartum, and on maternal and umbilical cord blood samples collected at delivery. Emtricitabine was measured by liquid chromatography-mass spectrometry with a quantification limit of 0.0118 mg/L. The target emtricitabine area under the concentration versus time curve, from time 0 to 24 hours post dose (AUC(0-24) ), was ≥7 mg h/L (≤30% reduction from the typical AUC of 10 mg h/L in nonpregnant historical controls). Third-trimester and postpartum pharmacokinetics were compared within subjects. RESULTS: Twenty-six women had pharmacokinetics assessed during the third trimester (median 35 weeks of gestation) and 22 postpartum (median 8 weeks postpartum). Mean [90% confidence interval (CI)] emtricitabine pharmacokinetic parameters during the third trimester vs. postpartum were, respectively: AUC: 8.0 (7.1-8.9) vs. 9.7 (8.6-10.9) mg h/L (P = 0.072); apparent clearance (CL/F): 25.0 (22.6-28.3) vs. 20.6 (18.4-23.2) L/h (P = 0.025); 24 hour post dose concentration (C(24) ): 0.058 (0.037-0.063) vs. 0.085 (0.070-0.010) mg/L (P = 0.006). The mean cord:maternal ratio was 1.2 (90% CI 1.0-1.5). The viral load was <400 HIV-1 RNA copies/mL in 24 of 26 women in the third trimester, in 24 of 26 at delivery, and in 15 of 19 postpartum. Within-subject comparisons demonstrated significantly higher CL/F and significantly lower C(24) during pregnancy; however, the C(24) was well above the inhibitory concentration 50%, or drug concentration that suppresses viral replication by half (IC(50) ) in all subjects. CONCLUSIONS: While we found higher emtricitabine CL/F and lower C(24) and AUC during pregnancy compared with postpartum, these changes were not sufficiently large to warrant dose adjustment during pregnancy. Umbilical cord blood concentrations were similar to maternal concentrations.

Lopinavir protein binding in HIV-1-infected pregnant women.

BACKGROUND: Pregnancy may alter protein binding (PB) of highly bound protease inhibitors due to changes in plasma concentrations of albumin and alpha-1 acid glycoprotein (AAG). Small changes in PB can greatly impact the fraction of drug unbound (FU) exerting pharmacological effect. We report lopinavir (LPV) PB during third trimester (antepartum, AP) compared to > or =1.7 weeks postpartum (PP) to determine if FU changes compensate for reduced total concentrations reported previously. METHODS: P1026s enrolled women receiving LPV/ritonavir, soft gel capsules 400/100 mg or 533/133 mg twice daily. LPV FU, albumin and AAG were determined AP and PP. RESULTS: AP/PP samples were available from 29/25 women respectively with all but one woman receiving the same dose AP/PP. LPV FU was increased 18% AP vs. PP (mean 0.96+/-0.16% AP vs. 0.82+/-0.21% PP, P=0.001). Mean protein concentrations were reduced AP (AAG=477 mg/L; albumin=3.28 mg/dL) vs. PP (AAG=1007 mg/L; albumin=3.85 mg/dL) (P<0.0001 for each comparison). AAG concentration correlated with LPV binding. Total LPV concentration did not correlate with LPV FU AP or PP. However, higher LPV concentration PP was associated with reduced PB and higher FU after adjustment for AAG. CONCLUSIONS: LPV FU was higher and AAG lower AP vs. PP. The 18% increase in LPV FU AP is smaller than the reduction in total LPV concentration reported previously and is not of sufficient magnitude to eliminate the need for an increased dose during pregnancy.

Should antiretroviral therapy for HIV infection be tailored for intracerebral penetration?

The continuous replication of HIV-1 in the central nervous system, in particular the brain, and its potential long-term deleterious effect is the focus of this review. Cognitive deficits are observed in a significant percentage of HIV-1-infected patients. That may occur despite successful peripheral suppression of the HIV-1 replication. Compartmentalisation of HIV-1 in the brain, genetic mutation of HIV-1, age, HCV coinfection and poor intracerebral penetration, as well as possibly a direct toxic effect of antiretroviral drugs, are factors that may account for potential creeping damage of the brain after many years of treatment. Patients with neurological symptoms or cognitive deficits may require another approach to the treatment of their HIV infection.

Pharmacokinetics of new 625 mg nelfinavir formulation during pregnancy and postpartum.

OBJECTIVES: Our objective was to evaluate the pharmacokinetics of nelfinavir (NFV) (625 mg tablets) 1250 mg twice daily during pregnancy and postpartum. METHODS: The participants were HIV-1-infected pregnant women enrolled in P1026s and receiving NFV (625 mg tablets) 1250 mg twice daily as part of routine clinical care. Intensive steady-state 12-h NFV pharmacokinetic profiles were performed during pregnancy and postpartum. The target NFV area under the plasma concentration-time curve (AUC(0-12)) was >or=10th percentile NFV AUC(0-12) in non-pregnant historical controls (18.5 microg h/mL). RESULTS: Of 27 patients receiving NFV, pharmacokinetic data were available for four (second trimester), 27 (third trimester) and 22 (postpartum) patients. The NFV maximum concentration (C(max)), 12-h post-dose concentration (C(12)) and AUC(0-12) were significantly lower during the third trimester compared to postpartum (P

Chronic administration of nevirapine during pregnancy: impact of pregnancy on pharmacokinetics.

OBJECTIVES: To determine the impact of pregnancy on the pharmacokinetics (PK) of nevirapine (NVP) during chronic dosing in HIV-infected women and appropriate NVP dosing in this population. METHODS: Twenty-six pregnant women participating in two open-label Pediatric AIDS Clinical Trials Group studies (P1022 and P1026S) were evaluated. Each patient received 200 mg NVP every 12 h and had PK evaluations during the second or third trimester; these evaluations were repeated postpartum. Paired maternal and cord blood NVP concentrations were collected at delivery in nine patients. Ante- and postpartum comparisons were made using paired t-tests and using a 'bioequivalence' approach to determine confidence interval (CI). RESULTS: The average NVP Area Under the Curve (AUC) was 56 +/- 13 mcg(*)h/mL antepartum and 61 +/- 15 mcg(*)h/mL postpartum. The typical parameters +/- standard error were apparent clearance (CL/F)=3.51 +/- 0.18 L/h and apparent volume of distribution (Vd/F)=121 +/- 19.8 L. There were no significant differences between antepartum and postpartum AUC or pre-dose concentrations. The AUC ratio was 0.90 with a 90% CI of the mean equal to 0.80-1.02. The median (+/- standard deviation) cord blood to maternal NVP concentration ratio was 0.91 +/- 0.90. CONCLUSIONS: Pregnancy does not alter NVP PK and the standard dose (200 mg every 12 h) is appropriate during pregnancy.

[Prophylaxis of nausea and vomiting after thyroid surgery: comparison of oral and intravenous dolasetron with intravenous droperidol and placebo]. / Prophylaxe von Ubelkeit und Erbrechen nach Schilddrüsen-Eingriffen: Vergleich von Dolasetron i.v. und oral mit Dehydrobenzperidol und Placebo.

OBJECTIVE: Postoperative nausea and vomiting (PONV) are among the most common complications in operative medicine. Especially thyroid surgery is frequently associated with PONV. It was the aim of this study to determine the efficacy of oral and intravenous dolasetron in comparison to intravenous droperidol (DHB) and placebo in the prevention of PONV. METHODS: 93 female and 43 male patients undergoing thyroid surgery were stratified according to gender and then randomised to receive double-blind one of four antiemetic regimes: 50 mg dolasetron given orally 45 minutes prior to induction of anaesthesia (group I), 12.5 mg dolasetron given intravenously during induction of anaesthesia (group II), 1.25 mg DHB given intravenously during induction of anaesthesia (group III) or placebo (group IV). General anaesthesia and preoperative management of the patients were standardised: premedication with chloracepate-dipotassium, induction with thiopentone, sufentanil and rocuronium, maintenance with N2O/O2, sevoflurane and repetitive doses of sufentanil and rocuronium, postoperative analgesia with metamizol and piritramide, antiemetic rescue-treatment with dimenhydrinate, metoclopramide and triflupromazine. Number of emetic episodes, the need for additional antiemetics and adverse events were recorded for 24 hours. Efficacy was measured by "complete-response" (CR = 0 emetic episodes or 1 emetic episode after 4 hours and no rescue-treatment) and "total-response" (TR = complete response plus no nausea, i.e., < 5 mm VAS rating of patients maximum nausea). RESULTS: Men: Only Dolasetron given intravenously reduced nausea and vomiting significantly, Dolasetron given orally reduced nausea, but not vomiting, DHB had no significant effects: CR 72.7% (group I), 100% (group II), 80% (group III), 63.6% (group IV); TR 72.7% (group I), 81.8% (group II), 50% (group III), 36.4% (group IV). Women: In all three treatment groups significantly less patients suffered from PONV compared to the placebo group (p < 0.05). There were no differences between the treatment groups: CR 58.3% (group I), 45.8% (group II), 52.2% (group III), 18.1% (group IV); TR 37.5% (group I), 33.3% (group II), 39.1% (group III), 13.6% (group IV). There were no adverse events in any group. CONCLUSIONS: Our results confirm the expected high incidence of PONV after thyroid surgery, especially in female patients. Single doses of oral and intravenous dolasetron and intravenous droperidol reduced PONV effectively in female patients undergoing thyroid surgery. Dolasetron seems to be the more effective substance in male patients. Both substances can be administered safely and are well tolerated.

Human endogenous retrovirus protein cORF supports cell transformation and associates with the promyelocytic leukemia zinc finger protein.

Human endogenous retrovirus sequences (HERVs) reside in the genomes of primates and humans for several million years. The majority of HERVs is non-coding but a limited set is intact and can express proteins. We have recently identified an almost intact HERV-K(HML-2) provirus on chromosome 7 and have documented that most patients with germ cell tumors (GCTs) display antibodies directed against proteins of HERV-K(HML-2). To address whether these proteins merely represent tumor markers or contribute to neoplastic transformation, we examined the transforming potential of various HERV sequences and studied physical interactions between HERV and cellular proteins by yeast two-hybrid and biochemical assays. cORF, a protein encoded by the C-terminal open reading frame within the env gene, supports tumor growth in nude mice and associates with the promyelocytic leukemia zinc finger protein (PLZF). The interaction domains map between amino acid residues 21 and 87 of cORF, and between residues 245 and 543 of PLZF. PLZF is critical for spermatogenesis in mice. Abnormal spermatogenesis or maturation of gonocytes is thought to predispose humans to the development of germ cell tumors. Thus, cORF of human endogenous retroviruses may contribute to tumor development by interfering with processes during spermatogenesis that involve PLZF.

Evaluation of a home kit blood glucose monitoring device

A blood glucose monitoring device, the *Diascan, is commonly used in Trinidad and Tobago. A prospective study was conducted to examine the accuracy of a Diascan unit in measuring blood glucose levels in or capillary venous blood of patients in a hospital ward. The Diascan measurements were compared to those from two laboratories which independently measured the venous blood or the venous plasma glucose levels. Although there was reasonably good correlation between measurements from the two laboratories (r=0.85) results from the Diascan showed poor correlations with those from the laboratories, with Pearson's correlation coefficients ranging from 0.32 to 0.64. An error grid analysis showed that the Diascan measurements would have resulted in inappropriate decisions relating to treatment regimens in 26 percent of cases. The results suggest that, when crucial deisions have to be made with respect to patients' blood glucose levels, it may be risky to rely solely on measurements from the Diascan.(AU)

Evaluation of a home kit blood glucose monitoring device

A blood glucose monitoring device, the Diascan, is commonly used in Trinidad and Tobago. A prospective study was conducted to examine the accuracy of a Diascan unit in measuring blood glucose levels in or capillary venous blood of patients in a hospital ward. The Diascan measurements were compared to those from two laboratories which independently measured the venous blood or the venous plasma glucose levels. Although there was reasonably good correlation between measurements from the two laboratories (r = 0.85) results from the Diascan showed poor correlations with those from the laboratories, with Pearson's correlation coefficients ranging from 0.32 to 0.64. An error grid analysis showed that the Diascan measurements would have resulted in inappropriate decisions relating to treatment regimens in 26of cases. The results suggest that, when crucial decisions have to be made with respect to patients' blood glucose levels, it may be risky to rely solely on measurements from the Diascan.

The condom: an effective penile dressing.

PIP: An effective penile dressing should support the wound, prevent contamination, and minimize edema and hematoma formation. Traditional penile dressings are cumbersome to apply and hard to secure. This report describes use of a condom to provide support after operations on the adult penis. After surgery, the penis is loosely wrapped with sterile gauze and a condom is rolled down over the dressing to the base of the penis. The tip of the condom is cut off and the ring of latex at its base is divided to prevent constriction. Patients can urinate through the excised tip. In 12 patients who received this regimen, the dressing remained in place for the desired duration and condom removal was painless. The most common indication for use of this dressing has been Nesbit's procedure.^ieng

Evaluation of a home kit blood glucose monitoring device.

A blood glucose monitoring device, the Diascan, is commonly used in Trinidad and Tobago. A prospective study was conducted to examine the accuracy of a Diascan unit in measuring blood glucose levels in or capillary venous blood of patients in a hospital ward. The Diascan measurements were compared to those from two laboratories which independently measured the venous blood or the venous plasma glucose levels. Although there was reasonably good correlation between measurements from the two laboratories (r = 0.85) results from the Diascan showed poor correlations with those from the laboratories, with Pearson's correlation coefficients ranging from 0.32 to 0.64. An error grid analysis showed that the Diascan measurements would have resulted in inappropriate decisions relating to treatment regimens in 26% of cases. The results suggest that, when crucial decisions have to be made with respect to patients' blood glucose levels, it may be risky to rely solely on measurements from the Diascan.

Specificity of antibodies directed against Env protein of human endogenous retroviruses in patients with germ cell tumors.

We report here that 85% of the patients with germ cell tumors (GCTs) produce antibodies directed against Env protein of human endogenous retroviruses. Individuals that received antitumor treatment showed a decrease with time in their antibody titers. Importantly, of the rare cases of non-GCT individuals with Env-antibodies (n= 15, 0.8%), none produced antibodies directed against the transmembrane domain (TM), whereas all tested Env-positive GCT patients (n= 49) generated such antibodies at high titers. TM is required for Env to be expressed at the cell surface. Thus, anti-TM antibodies constitute highly specific markers for GCT and may hint at a function of Env during tumorigenesis.

Characterization of the human endogenous retrovirus K proteinase.

The proteinase of the human endogenous retrovirus K (HERV-K) shows similarity to retrovirus aspartic proteinases. It is translated from a transcript composed of gag and prt. The proteinase was expressed either as full-length native protein or as truncated protein in Escherichia coli. Functional protein was demonstrated by its autocatalytic cleavage into an 18 kDa fragment recognized by a polyclonal antiserum. This autocatalytic cleavage was specifically inhibited by a human immunodeficiency virus type 1 proteinase inhibitor. The HERV-K proteinase expressed in E. coli was capable of cleaving HERV-K Gag translated in vitro. Major protein fragments of 39 and 30 kDa, and minor protein fragments of 26, 22 and 21 kDa were obtained. Similar fragments are also observed in the human teratocarcinoma cell line Tera1. Our data suggest that the HERV-K proteinase is functionally equivalent to other retrovirus proteinases and thus probably functions in the processing of Gag precursor protein.

Human endogenous retrovirus K10: expression of Gag protein and detection of antibodies in patients with seminomas.

The human endogenous retrovirus K10 (HERV-K10) has been identified in the human genome by its homology to retroviruses of other vertebrates (M. Ono, T. Yasunaga, T. Miyata, and H. Ushikubo, J. Virol. 60:589-598, 1986). Using PCR amplification, DNA cloning, sequencing, and procaryotic expression, we were able to demonstrate that HERV-K10 encodes a 73-kDa protein which was processed by a HERV-K10-encoded protease to yield proteins p22/p26, p30, and p15/16. Analysis of the teratocarcinoma cell line Tera 1 or tumor tissues by immunoblotting demonstrated that the 80-kDa polyprotein of HERV-K10 gag and a processed protein of 39 kDa were expressed. In addition, a major protein of 39 kDa and additional species of 30, 22, 19, and 17 kDa could be detected in the supernatant of Tera 1 cells, suggesting that HERV-K10 Gag proteins are either secreted or processed to probably incomplete viral particles. In addition, the gag gene of HERV-K10 was expressed in the baculovirus system. Using this recombinant system to test antisera from patients with different diseases and healthy individuals, we were able to detect antibodies against the N-terminal part of HERV-K10 Gag in 2 to 4% of groups of tumor patients with titers ranging between 1:80 and 1:640, while approximately 0.1 to 0.5% of healthy individuals exhibited antibodies with lower titers. In contrast, patients with seminoma had antibody titers in the range of 1:2,560 at the time when the tumor was detected. Immunohistochemistry using specific rabbit sera or monoclonal antibodies against HERV-K10 Gag revealed that the Gag protein is expressed in the cytoplasm of the tumor cells. Furthermore, an 80-kDa protein corresponding to the HERV-K10 Gag polyprotein could be detected in tumor biopsies. For the first time, these data indicate that HERV-K10 Gag proteins are synthesized in seminoma cells and tumors exhibit relatively high antibody titers against Gag. So far, no information on which role HERV-K10 plays in the development of this tumor exists.