Frailty and health-related quality of life among older people living with HIV pre- and post-COVID-19 pandemic onset: A cross-sectional study.

INTRODUCTION: Antiretroviral therapy increased the survival and life expectancy of People living With HIV (PWH). Frailty-related syndromes among older PWH (aged 50+ years) may affect their Health-related Quality of Life (HQoL). Additionally, the COVID-19 pandemic has impacted health-related outcomes. This study aimed to estimate the prevalence of frailty and pre-frailty among older PWH, and to explore associations of HQoL with the study assessment period and frailty status. METHODS: Cross-sectional study conducted pre- (23-Mar-2019 to 5-Mar-2020) and post-COVID-19 pandemic onset (23-Jun-2021 to 5-May-2022), among older PWH at INI-Fiocruz, the largest cohort of PWH in Rio de Janeiro, Brazil. We measured frailty using Fried assessment, consisting of five domains: unintentional weight loss; self-reported exhaustion, weakness, slow walking speed, low physical activity. HQoL was assessed using the ACTG SF-21, which contains 21 questions divided into 8 domains. We used Chi-Square test, Fisher's exact test, Kruskal-Wallis and ranksum test for comparisons. RESULTS: We included 250 older PWH: 109 (43.6 %) pre- and 141 (56.4 %) post-COVID-19 pandemic onset. Median age was 60-years (IQR: 55‒64). Most self-identified as cisgender men 152 (60.8 %), Pardo/Black 146 (58.4 %), with completed secondary education or less 181 (72.7 %) and low income 132 (52.8 %). Overall, prevalence of frailty and pre-frailty were 9.2 % (95 % CI: 8.1‒10.3) and 61.6 % (95 % CI: 54.0‒69.2). Prevalence of frailty in the pre- and pos-COVID-19 pandemic periods were 7.3 % and 10.6 % (p = 0.66). HQoL scores were lower among participants with frailty compared to those with non-frailty and pre-frailty in all eight domains, and among those included in the post-COVID-19 compared to pre-COVID-19 period for four domains. CONCLUSIONS: We observed low prevalence of frailty, but high prevalence of pre-frailty among older PWH. Frailty status did not differ according to the COVID-19 assessment period. Assessment of frailty and HQoL should be incorporated in clinical practice for older PWH. Programs to reverse or prevent frailty should be implemented within the public health system.

Frailty and health-related quality of life among older people living with HIV pre- and post-COVID-19 pandemic onset: A cross-sectional study

ABSTRACT Introduction: Antiretroviral therapy increased the survival and life expectancy of People living With HIV (PWH). Frailty-related syndromes among older PWH (aged 50+ years) may affect their Health-related Quality of Life (HQoL). Additionally, the COVID-19 pandemic has impacted health-related outcomes. This study aimed to estimate the prevalence of frailty and pre-frailty among older PWH, and to explore associations of HQoL with the study assessment period and frailty status. Methods: Cross-sectional study conducted pre- (23-Mar-2019 to 5-Mar-2020) and post-COVID-19 pandemic onset (23-Jun-2021 to 5-May-2022), among older PWH at INI-Fiocruz, the largest cohort of PWH in Rio de Janeiro, Brazil. We measured frailty using Fried assessment, consisting of five domains: unintentional weight loss; self-reported exhaustion, weakness, slow walking speed, low physical activity. HQoL was assessed using the ACTG SF-21, which contains 21 questions divided into 8 domains. We used Chi-Square test, Fisher's exact test, Kruskal-Wallis and ranksum test for comparisons. Results: We included 250 older PWH: 109 (43.6 %) pre- and 141 (56.4 %) post-COVID-19 pandemic onset. Median age was 60-years (IQR: 55‒64). Most self-identified as cisgender men 152 (60.8 %), Pardo/Black 146 (58.4 %), with completed secondary education or less 181 (72.7 %) and low income 132 (52.8 %). Overall, prevalence of frailty and pre-frailty were 9.2 % (95 % CI: 8.1‒10.3) and 61.6 % (95 % CI: 54.0‒69.2). Prevalence of frailty in the pre- and pos-COVID-19 pandemic periods were 7.3 % and 10.6 % (p = 0.66). HQoL scores were lower among participants with frailty compared to those with non-frailty and pre-frailty in all eight domains, and among those included in the post-COVID-19 compared to pre-COVID-19 period for four domains. Conclusions: We observed low prevalence of frailty, but high prevalence of pre-frailty among older PWH. Frailty status did not differ according to the COVID-19 assessment period. Assessment of frailty and HQoL should be incorporated in clinical practice for older PWH. Programs to reverse or prevent frailty should be implemented within the public health system.

Pharmacotherapeutic profile, polypharmacy and its associated factors in a cohort of people living with HIV in Brazil.

BACKGROUND: The increased survival provided by the access, development, and evolution of antiretroviral drugs (ARV) greatly increased the life expectancy of people living with HIV (PWH). This has also led to an increased occurrence of diseases or morbidities related to aging. In individuals with multiple comorbidities, the simultaneous use of multiple medications, also known as polypharmacy, is common, and rational use of medications is essential. This study aims to describe the pharmacotherapeutic profile, estimate the prevalence of polypharmacy and identify factors associated with polypharmacy in a cohort of adult PWH from a referral unit in Rio de Janeiro, Brazil. METHODS: Cross-sectional study including PWH on ARV who received at least one medical prescription (outpatient/hospitalized) in 2019. We described the proportion of prescribed medications according to ARV and Anatomical Therapeutic Chemical (ATC) classes stratified by age (< 50 vs. ≥50 years). Polypharmacy was defined as ≥ 5 medications prescribed beyond ARV. Logistic regression models assessed demographic and clinical factors associated with polypharmacy. RESULTS: A total of 143,306 prescriptions of 4547 PWH were analyzed. Median age was 44.4 years (IQR:35.4-54.1) and 1615 (35.6%) were ≥ 50 years. A total of 2958 (65.1%) participants self-identified as cisgender man, 1365 (30.0%) as cisgender woman, and 224 (4.9%) as transgender women. Most self-declared Black/Pardo (2582; 65.1%) and 1984 (44.0%) completed elementary education or less. Median time since HIV diagnosis was 10.9 years (IQR:6.2-17.7). Most frequently prescribed concomitant medications were nervous system (64.8%), antiinfectives for systemic use (60.0%), alimentary tract and metabolism (45.9%), cardiovascular system (40.0%) and respiratory system (37.1%). Prevalence of polypharmacy was 50.6% (95%CI: 49.2-52.1). Model results indicated that being older, self-identify as cisgender woman, having less education and longer time since HIV diagnosis increased the odds of polypharmacy. CONCLUSIONS: We found high rates of polypharmacy and concomitant medication use in a cohort of PWH in Brazil. Targeted interventions should be prioritized to prevent interactions and improve treatment, especially among individuals using central nervous system and cardiovascular medications, as well as certain groups such as cisgender women, older individuals and those with lower education. Standardized protocols for continuous review of patients' therapeutic regimens should be implemented.

Pharmacokinetics of Antiretroviral Drugs in Older People Living with HIV: A Systematic Review.

BACKGROUND AND OBJECTIVE: The life expectancy of people living with HIV (PLWHIV) has significantly improved in recent decades, mostly due to antiretroviral (ARV) therapy. Aging can affect the pharmacokinetics of drugs and, as a consequence, increase the risk of drug interactions and toxicity that may impact treatment. The aim of this study was to carry out a systematic review of the literature on the effect of aging on ARV pharmacokinetics. METHODS: Searches were performed in the BVS, EMBASE and PUBMED databases until November 2022. All studies available in English, Spanish and Portuguese investigating the pharmacokinetics of ARV approved by the US Food and Drug Administration (FDA) from 2005 to 2020 were selected. Peer-reviewed publications were included if they met all criteria: adults (≥ 18 years of age) living with or without HIV; report any pharmacokinetic parameter or plasma concentration of at least one of the following ARVs: tenofovir alafenamide fumarate (TAF); doravirine (DOR), rilpivirine (RIL) and etravirine (ETR); darunavir (DRV), tipranavir (TPV) and fostemsavir (FTR); dolutegravir (DTG), raltegravir (RAL), bictegravir (BIC) and elvitegravir (EVG); maraviroc (MVC); ibalizumab (IBA); cobicistat (COBI). Pharmacokinetic parameters were reported stratified per age group: young adults (aged 18-49 years) or older (age ≥ 50 years) and all studies were evaluated for quality. The review protocol was registered in the PROSPERO database (registration number CRD42021236432). RESULTS: Among 97 studies included, 20 reported pharmacokinetic evaluation in older individuals (age ≥ 50 years). Twenty five percent of the articles were phase I randomized clinical trials with HIV-negative participants and non-compartmental pharmacokinetic analysis presenting the parameters area under the curve (AUC) and peak drug concentration (Cmax). Seven age-stratified studies evaluated BIC, ETR, DRV, DTG, DOR and RAL. We found publications with discordant results for ETR and DTG pharmacokinetics in different age groups. DRV exposure was highly variable but modestly increased in aging PLWHIV. In contrast, no influence of age on BIC, DOR and RAL exposure was observed. A variability in pharmacokinetic parameters could be observed for the other ARVs (TAF and MVC) in different age groups. CONCLUSION: Exposure to DRV increases modestly with age, while exposure to BIC, DOR and RAL appears to be unaffected by age. As the available evidence to confirm a potential effect of aging on ARV pharmacokinetics is limited, further studies are necessary.

Estradiol and Spironolactone Plasma Pharmacokinetics Among Brazilian Transgender Women Using HIV Pre-Exposure Prophylaxis: Analysis of Potential Interactions.

BACKGROUND AND OBJECTIVE: An important barrier to HIV prevention among transgender women (TGW) is the concern that oral pre-exposure prophylaxis (PrEP) negatively affects the efficacy of feminizing hormone therapy (FHT). We aimed to assess the impact of PrEP on FHT pharmacokinetics (PK) among TGW from Brazil. METHODS: We performed a drug-drug interaction sub-study among TGW enrolled in a daily oral PrEP demonstration study (PrEParadas, NCT03220152). Participants had a first PK assessment (PK1) 15 days after FHT (estradiol valerate 2-6 mg plus spironolactone 100-200 mg) initiation and then started PrEP (tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg). A second PK evaluation was performed 12 weeks later (PK2). Blood samples were collected prior and after the directly observed dosing (0, 0.5, 1, 2, 4, 6, 8, and 24 hours). Pharmacokinetic parameters of estradiol, spironolactone, and metabolites were estimated by non-compartmental analysis (Monolix 2021R2, Lixoft®) and compared as geometric mean ratios (GMRs, 90% confidence interval [CI]). RESULTS: Among 19 TGW who completed the substudy, median age was 26 years (interquartile range: 23-27.5). Estradiol area under the plasma concentration-time curve (AUCτ) and trough concentrations did not differ between PK1 and PK2 evaluations (GMR [90% CI]: 0.89 [0.76-1.04] and 1.06 [0.94-1.20], respectively). Spironolactone and canrenone AUCτ were statistically lower at PK2 than PK1 (0.76 [0.65-0.89] and 0.85 [0.78-0.94], respectively). Canrenone maximum concentration was also lower at PK2 than PK1 (0.82 [0.74-0.91]). CONCLUSION: Estradiol PK was not influenced by PrEP concomitant use. The small differences observed in some spironolactone and canrenone PK parameters should not prevent the concomitant use of estradiol-based FHT and PrEP. TRIAL REGISTRATION: This trial (NCT03220152) was registered on July 18, 2017.

Development and validation of liquid chromatography-tandem mass spectrometry method to quantify dasatinib in plasma and its application to a pharmacokinetic study

Abstract Dasatinib, a potent oral multi-targeted kinase inhibitor against Src and Bcr-Abl, can decrease inflammatory response in sepsis. A simple and cost-effective method for determination of an effective dose dasatinib was established. This method was validated in human plasma, with the aim of reducing the number of animals used, thus, avoiding ethical problems. Dasatinib and internal standard lopinavir were extracted from 180 uL of plasma using liquid-liquid extraction with methyl tert-butil ether, followed by liquid chromatography coupled to triple quadrupole mass spectrometry in multiple reaction monitoring mode. For the pharmacokinetic study, 1 mg/kg of dasatinib was administered to mice with and without sepsis. The method was linear over the concentration range of 1-98 ng/mL for DAS in mice and human plasma, with r2>0.99 and presented intra- and interday precision within the range of 2.3 - 6.2 and 4.3 - 7.0%, respectively. Further intra- and interday accuracy was within the range of 88.2 - 105.8 and 90.6 - 101.7%, respectively. The mice with sepsis showed AUC0-t = 2076.06 h*ng/mL and Cmax =102.73 ng/mL and mice without sepsis presented AUC0-t = 2128.46 h*ng/mL. Cmax = 164.5 ng/mL. The described analytical method was successfully employed in pharmacokinetic study of DAS in mice.

Impact of feminizing hormone therapy on tenofovir and emtricitabine plasma pharmacokinetics: a nested drug-drug interaction study in a cohort of Brazilian transgender women using HIV pre-exposure prophylaxis.

OBJECTIVES: Potential interactions between feminizing hormone therapy (FHT) and pre-exposure prophylaxis (PrEP) may be a barrier to PrEP use among transgender women (TGW). We aimed to assess the impact of FHT on PrEP plasma pharmacokinetics (PK) among TGW. METHODS: This was a PK substudy of the effects of FHT on tenofovir disoproxil fumarate/emtricitabine nested to a trans-specific PrEP demonstration study (NCT03220152). Participants were assigned to receive PrEP only (noFHT) or standardized FHT (sFHT; oestradiol valerate 2-6 mg plus spironolactone 100-300 mg) plus PrEP for 12 weeks, after which they could start any FHT (aFHT). Short- and long-term PK assessment occurred at Weeks 12 and 30-48, respectively (plasma samples prior and 0.5, 1, 2, 4, 6, 8 and 24 h after dose). Non-compartmental PK parameters of tenofovir and emtricitabine were compared as geometric mean ratios (GMRs) between noFHT and PrEP and FHT (sFHT at short-term PK; aFHT at long-term PK) participants. RESULTS: No differences in tenofovir and emtricitabine plasma PK parameters were observed between the short-term PK of noFHT (n = 12) and sFHT participants (n = 18), except for emtricitabine Cmax [GMR: 1.15 (95% CI: 1.01-1.32)], or between noFHT short-term PK and aFHT long-term PK (n = 13). Most participants were on oestradiol valerate 2 mg at the short-term PK (56%) and 4 mg at the long-term PK (54%). Median (IQR) oestradiol levels were 56.8 (43.2-65.4) pg/mL at short-term PK (sFHT) and 44.8 (24.70-57.30) pg/mL at long-term PK (aFHT). No participants in this analysis seroconverted during the study. CONCLUSIONS: Our results indicate no interaction of FHT on tenofovir levels, further supporting PrEP use among TGW using FHT.

Low PrEP adherence despite high retention among transgender women in Brazil: the PrEParadas study.

INTRODUCTION: We aimed to evaluate daily oral pre-exposure prophylaxis (PrEP) uptake, retention, and adherence and predictors of study non-attendance and low PrEP adherence in a Brazilian trans-specific 48-week study (PrEParadas). METHODS: We enrolled transgender women (TGW) engaging in high-risk sexual behaviours between August 2017 and December 2018. PrEP adherence was based on tenofovir diphosphate concentrations in dried blood spots (DBS). We used random effects logistic regression models and ordinal models to estimate the odds of having a missed visit and of low PrEP adherence, respectively. Multivariable models were adjusted for variables with p-value<0.10 in the univariate analysis. RESULTS: From the 271 eligible, 130 participants were enrolled in the study (PrEP uptake: 48%), out of which 111 (85.4%) were retained at 48 weeks. Multivariable model for study non-attendance included study visit, age, main sexual partner and stimulant use. The odds of missing a visit increased after the week 24. Participants aged 18-24 (adjusted odds ratio [aOR] = 8.76, 95% CI: 2.09-36.7) and 25-34 years (aOR = 6.79, 95% CI: 1.72-26.8) compared to TGW aged 35+ years had significantly higher odds of having a missed visit. The odds of a missed visit were higher among participants reporting stimulant use (aOR = 4.99, 95% CI: 1.37-18.1) compared to no stimulant use. DBS levels at week 48 showed that 42 (38.5%), 14 (12.8%) and 53 (48.6%) of 109 participants had low, moderate and high PrEP adherence. Multivariable model for low PrEP adherence included study visit, age, schooling, race/colour, housing, binge drinking, stimulant use, feminizing hormone therapy (FHT) use and received text message. Low PrEP adherence was significantly higher among participants with less years of schooling (aOR = 6.71, 95% CI: 1.30-34.5) and had a borderline association with Black colour/race (aOR = 6.72, 95% CI: 0.94-47.8). Participants using the FHT available at the site had decreased odds of low PrEP adherence (aOR = 0.38, 95% CI: 0.16-0.88). No participant seroconverted over the course of the study. CONCLUSIONS: Although high PrEP retention can be achieved in a gender-affirming setting, PrEP adherence may be an important challenge faced among TGW due to social disparities. The scale-up of prevention tools like PrEP will have to address systemic social determinants as these stand as important barriers for TGW's access to health services.

Extended stability study of an extemporaneously analgesic solution of clonidine, ropivacaine and fentanyl

Abstract The aim of this work was to perform an extended stability study for the analgesic containing fentanyl, clonidine and ropivacaine in physiological saline solution 0.9% at different infusion sites, such as infusion bags, epidural infusion sets and syringes. The extended stability was assessed by an HPLC system equipped with a photodiode array detector set at 210 nm. The separation was conducted on a C18 column maintained at 40˚C and using an isocratic mobile phase consisted of buffer solution-methanol-acetonitrile (45:45:10, v/v/v). The presence of particulate matter and the pH of each solution were also investigated. Twenty-four hours after the preparation, the formation of one suspected product was observed and for all drugs, in 24 hours it was observed the concentration decrease in different sets (PVC infusion bags, syringes and epidural infusion administration sets). The pH values of each solution varied no more than 5% during the study and no particle was observed. Conclusion: The extended stability study was applied to the analgesic solution and promoted the detection of an unexpected peak in 24 hours. Based on it, further stability studies are necessary to determine the extended stability data.

Pretreatment and non-specific binding in ultrafiltration device: Impact on protease inhibitor quantification.

INTRODUCTION: Ultrafiltration (UF) is used to separate unbound drugs; however, non-specific binding (NSB) may be a limiting factor of this technique. Pretreatment of UF devices has been suggested to reduce NSB. Therefore, the pretreatment methodologies for UF devices were evaluated in order to test their effectiveness in reducing NSB of protease inhibitors (PIs). METHODOLOGY: Two PIs (lopinavir-LPV and ritonavir-RTV) were tested. UF devices were pretreated with ultrapure water, Tween-20 or Tween-80. To evaluate the NSB, after UF devices being pretreated, ultrafiltrate solutions containing the analytes at two concentrations (low and high) were used. Samples were quantified by LC-MS/MS. RESULTS: UF devices pretreated with Tween-5% had the lowest NSB for both analytes. NSB values varied between 7 and 11% at low concentration 16-34% at high LPV concentration, respectively. For RTV, NSB was approximately 6% for low concentration and 18% for high concentration. Failure to completely remove Tween in UF devices could results in an overestimation of NSB. CONCLUSION: Pretreatment of UF device with Tween and subsequent removal proved to be effective in reducing NSB of PI.

Relationship of anti-tuberculosis drug-induced liver injury and genetic polymorphisms in CYP2E1 and GST

ABSTRACT Setting: Treatment of tuberculosis (TB) can result in Drug-Induced Liver Injury (DILI) since hepatotoxic metabolites are formed during the biotransformation of isoniazid (INH).DILI can be related to the genetic profile of the patient. Single nucleotide polymorphisms in the CYP2E1 gene and GSTM1 and GSTT1 deletion polymorphisms have been associated with adverse events caused by INH. Objective: To characterize the genetic polymorphisms of CYP2E1, GSTT1 and GSTM1 in TB carriers. Design: This is an observational prospective cohort study of 45 patients undergoing treatment of TB. PCR-RFLP and multiplex-PCR were used. Results: The distribution of genotypic frequency in the promoter region (CYP2E1 gene) was: 98% wild genotype and 2% heterozygous. Intronic region: 78% wild genotype; 20% heterozygous and 2% homozygous variant. GST enzyme genes: 24% Null GSTM1 and 22% Null GSTT1. Patients with any variant allele of the CYP2E1 gene were grouped in the statistical analyses. Conclusion: Patients with the CYP2E1 variant genotype or Null GSTT1 showed higher risk of presenting DILI (p = 0.09; OR: 4.57; 95% CI: 0.75-27.6). Individuals with both genotypes had no increased risk compared to individuals with one genotype.

Relationship of anti-tuberculosis drug-induced liver injury and genetic polymorphisms in CYP2E1 and GST.

SETTING: Treatment of tuberculosis (TB) can result in Drug-Induced Liver Injury (DILI) since hepatotoxic metabolites are formed during the biotransformation of isoniazid (INH). DILI can be related to the genetic profile of the patient. Single nucleotide polymorphisms in the CYP2E1 gene and GSTM1 and GSTT1 deletion polymorphisms have been associated with adverse events caused by INH. OBJECTIVE: To characterize the genetic polymorphisms of CYP2E1, GSTT1 and GSTM1 in TB carriers. DESIGN: This is an observational prospective cohort study of 45 patients undergoing treatment of TB. PCR-RFLP and multiplex-PCR were used. RESULTS: The distribution of genotypic frequency in the promoter region (CYP2E1 gene) was: 98% wild genotype and 2% heterozygous. Intronic region: 78% wild genotype; 20% heterozygous and 2% homozygous variant. GST enzyme genes: 24% Null GSTM1 and 22% Null GSTT1. Patients with any variant allele of the CYP2E1 gene were grouped in the statistical analyses. CONCLUSION: Patients with the CYP2E1 variant genotype or Null GSTT1 showed higher risk of presenting DILI (p=0.09; OR: 4.57; 95% CI: 0.75-27.6). Individuals with both genotypes had no increased risk compared to individuals with one genotype.

A novel and simple LC-MS/MS quantitative method for dextromethorphan and dextrorphan in oral fluid.

Aim: To develop and validate a simple method using LC-MS/MS for determination of dextromethorphan (DXM) and dextrorphan (DT) in human oral fluid. Results: Following protein precipitation, chromatographic separation used a phenyl column with isocratic elution (1 ml/min) of 10 mM ammonium-formate buffer and acetonitrile (65:35; v/v) with 0.1% formic acid. Retention times were 2.6 min for DT and 5 min for DXM. Total run time was 7 min. The intra- and inter-assay deviations (accuracy) for DT (1-100 ng/ml) and DXM (5-1000 ng/ml) ranged from -13.6 to 8.8% and -9.6 to 5.7%, respectively. Precision variations were ≤7.5%. Matrix effect was ≤11.8%. Conclusion: This method may prove helpful for quantification of DT and DXM in oral fluid for either clinical or toxicological purposes.

A Rapid and Simple HPLC Method for Therapeutic Monitoring of Vancomycin.

Therapeutic monitoring of the antibiotic vancomycin is important to achieve specific plasma concentration and prevent toxic effects. Several assays have been described for vancomycin determination in clinical practice, but high-performance liquid chromatography is still considered the gold standard for the quantification of vancomycin. In this study, we developed a new and rapid high-performance liquid chromatography method requiring 50 µL of plasma for the quantification of vancomycin. Acetonitrile was used for processing plasma by protein precipitation (1:2.5). Isocratic chromatographic analysis was carried out on a C18 silica-based (2.7 µm) column with the mobile phase containing 20 mM ammonium acetate/formic acid buffer (pH 4.0):methanol 88:12 (v/v). A diode array detector was used for UV detection at 240 nm. This method was validated according to the Brazilian Health Surveillance Agency legislation and International Conference on Harmonization guidelines. The measurement range was 1-100 µg/mL, analysis time was 8 min, and intermediate precision was <12%, supporting the present method as a fast, simple, and effective alternative for therapeutic monitoring of vancomycin.

Randomized clinical trial comparing the pharmacokinetics of standard- and increased-dosage lopinavir-ritonavir coformulation tablets in HIV-positive pregnant women.

A lopinavir-ritonavir (LPV/r)-based regimen is recommended during pregnancy to reduce the risk of HIV mother-to-child transmission, but the appropriate dose is controversial. We compared the pharmacokinetics of standard and increased LPV/r doses during pregnancy. This randomized, open-label prospective study enrolled 60 pregnant women between gestational weeks 14 and 30. The participants received either the standard dose (400/100 mg twice a day [BID]) or increased dose (600/150 mg BID) of LPV/r tablets during pregnancy and the standard dose for 6 weeks after childbirth. Pharmacokinetics analysis was performed using a high-performance liquid chromatography-tandem mass spectrometry method. Adherent participants who received the standard dose presented minimum LPV concentrations of 4.4, 4.3, and 6.1 µg/ml in the second and third trimesters and postpartum, respectively. The increased-dose group exhibited values of 7.9, 6.9, and 9.2 µg/ml at the same three time points. Although LPV exposure was significantly higher in the increased-dose group, the standard dose produced therapeutic levels of LPV against wild-type virus in all adherent participants, except one patient in the third trimester; 50%, 37.5%, and 25%, and 0%, 15%, and 0% of the participants in the standard- and increased-dose groups failed to achieve therapeutic levels against resistant viruses during the second and third trimesters and after childbirth, respectively. After 12 weeks of treatment and after childbirth, all adherent participants achieved undetectable HIV viral loads, and their babies (49/54) were uninfected. No serious drug-related adverse events were observed. We conclude that the standard dose is appropriate for use during pregnancy and that an increased dose may be necessary for women harboring resistant HIV. (This study has been registered at ClinicalTrials.gov under registration no. NCT00605098.).

Implementation of vancomycin dosing nomogram in an electronic prescribing system: an innovative tool in antibiotic stewardship

Vancomycin (VAN) is the gold standard therapy for Methicillin-resistant Staphylococcus aureus (MRSA) infections such as bacteremia and endocarditis. However, VAN suboptimal dosing for serious infections caused by S. aureus isolates that have elevated minimum inhibitory concentration (MIC), could be associated with poor outcome. Better understanding of VAN pharmacokinetics and pharmacodynamics (PK/PD) has led to the creation of new recommendations with optimized dosing regimens for the treatment of MRSA infections. For severe infectious, such as pneumonia and endocarditis, a VAN serum trough concentration of 15-20 mg/L at the steady state should be targeted. The aim of this study was to show how a nomogram with updated VAN dosing was devised and how it was implemented in the electronic prescribing (e-prescribing) system of a teaching hospital. VAN loading dose and maintenance doses were calculated from a pharmacokinetic equation using basic parameters: weight, estimated creatinine clearance, as well as peak and trough serum concentrations. The implementation of the VAN dosing nomogram in the hospital e-prescribing system definitively changed the long-standing medical prescription fallacy of "same dose fits all". Finally, this computer-based electronic program has allowed a wide-ranging intervention and should be recognized as a powerful tool for implementation in antimicrobial stewardship programs.

Vancomicina (VAN) é utilizada como primeira escolha na terapia de infecções causadas por Staphylococcus aureus resistentes à meticilina (MRSA), como bacteremia e endocardite. Entretanto, o aumento na concentração inibitória mínima (CIM) de isolados de S. aureus e doses subterapêuticas de VAN podem estar associados à falha terapêutica. Para o melhor entendimento sobre o perfil farmacocinético e farmacodinâmico (PK/PD) da VAN foram elaboradas novas recomendações para terapia de infecções causadas por MRSA. Para terapia de infecções graves, como pneumonia e endocardite, a concentração sérica do vale de VAN de 15-20 mg/L no estado de equilíbrio dinâmico deve ser o alvo. O objetivo do estudo foi desenvolver um nomograma com doses atualizadas de VAN e demonstrar como ele foi implementado no sistema de prescrição eletrônica em um Hospital Universitário. As doses de ataque e manutenção foram calculadas a partir de equações farmacocinéticas, utilizando parâmetros fundamentais: peso, depuração de creatinina, concentrações séricas do pico e do vale. A implementação de um nomograma de doses de VAN em um sistema de prescrição eletrônica modificou definitivamente o inadequado hábito de que "a mesma dose cabe em todos". Finalmente, esta abrangente ferramenta tecnológica deve ser considerada como uma robusta estratégia num programa de uso racional de antibióticos.

The impact of SLCO1B1 polymorphisms on the plasma concentration of lopinavir and ritonavir in HIV-infected men.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: * There is large interindividual variability in the pharmacokinetics of protease inhibitors (PIs) among human immunodeficiency virus (HIV)-infected individuals under highly active antiretroviral therapy. * Protease inhibitor have been recently reported to be substrates of the SLCO1B1/OATP1 drug transporter. * A single nucleotide polymorphism (SNP) in the SLCO1B1 gene (521T-->C) was associated with plasma levels of lopinavir in HIV-infected individuals. WHAT THIS STUDY ADDS: * Data on the impact of three SLCO1B1 SNPs (521T-->C, 388A-->G, 463C-->A) on the trough plasma concentration of lopinavir and ritonavir in a cohort of 99 adult HIV-infected Brazilian men under stable highly active antiretroviral therapy. * Evidence that carriers of the 521C allele display significantly higher lopinavir, but not ritonavir plasma concentrations relative to the wild-type TT genotype. * No effect of either 388A-->G or 463C-->A SNPs on lopinavir or ritonavir plasma concentrations. * Further studies are required to confirm the clinical significance of the association between the SLCO1B1521T-->C polymorphism and lopinavir pharmacokinetics. AIMS: To investigate possible associations between three SLCO1B1 single nucleotide polymorphisms (388A-->G, 463C-->A, 521T-->C) and lopinavir/ritonavir plasma concentrations. METHODS: The study included 99 human immunodeficiency virus-infected men on stable highly active antiretroviral therapy containing lopinavir/ritonavir. Trough concentrations of lopinavir and ritonavir in plasma were quantified using liquid chromatography-tandem mass spectrometry. Genotyping of SLCO1B1388A-->G, 463C-->A and 521T-->C polymorphisms was performed by allelic discrimination using real-time polymerase chain reaction. RESULTS: The trough concentration of lopinavir in plasma is significantly associated with SLCO1B1521T-->C genotypes (P= 0.03). There is a significant trend for increasing concentrations of lopinavir from TT to TC to CC genotypes (P= 0.02). Carriers of the 521C allele display significantly higher lopinavir plasma concentrations relative to the wild-type TT genotype (P= 0.03). CONCLUSIONS: Reduced uptake of lopinavir by hepatocytes in carriers of the 521C allele may account for these results, but further studies to confirm the clinical importance of SLCO1B1 polymorphisms in lopinavir pharmacokinetics are warranted.

ABCB1 polymorphisms and the concentrations of lopinavir and ritonavir in blood, semen and saliva of HIV-infected men under antiretroviral therapy.

INTRODUCTION: Lopinavir and ritonavir are frequently included in highly active antiretroviral therapy (HAART) regimens for HIV infection. These drugs are substrates, and may also inhibit and/or induce the P-glycoprotein (ABCB1) transporter, encoded by the polymorphic ABCB1 gene. We investigated the impact of three common exonic ABCB1 polymorphisms on the concentrations of lopinavir and ritonavir in blood, semen and saliva of HIV-infected men under stable HAART containing ritonavir-boosted lopinavir. MATERIALS & METHODS: Blood, semen and saliva samples were collected from 113 subjects, 30-35 minutes before the scheduled morning dose of lopinavir/ritonavir, and trough drug concentrations were measured using LC/MS/MS. The 1236C>T, 2677G>T/A and 3435C>T polymorphisms were genotyped using the single base extension-termination method and ABCB1 haplotypes were statistically inferred. RESULTS: Median (25th-75th percentile) trough concentrations (ng/ml) of lopinavir in plasma, semen and saliva were 6326 (4070-8617), 286.0 (128.4-475.5) and 72.7 (38.0-119.6), respectively. The corresponding concentrations (ng/ml) for ritonavir were 261.8 (172.2-398.6), 17.7 (9.2-27.6) and 5.3 (3.2-9.0), respectively. Univariate and multivariate regression analysis revealed no influence of ABCB1 genotypes or haplotypes on the concentrations of lopinavir and ritonavir in plasma, semen and saliva of HIV-infected men under stable HAART treatment. CONCLUSION: The ABCB1 1236C>T, 2667G>T/A and 3435C>T genotypes and haplotypes are not predictors of lopinavir and ritonavir concentrations in blood plasma, semen or saliva of HIV-infected men under stable HAART treatment. The concentrations of lopinavir and ritonavir in saliva are not reliable predictors of the concentration of these drugs in semen.

Determination of lopinavir and ritonavir in blood plasma, seminal plasma, saliva and plasma ultra-filtrate by liquid chromatography/tandem mass spectrometry detection.

A method based on liquid-liquid extraction followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometry (ESI-MS/MS) detection was developed for the simultaneous determination of lopinavir (LPV) and ritonavir (RTV) in human blood, semen and saliva samples. The acquisition was performed in multiple reaction monitoring (MRM) mode, monitoring the transitions: m/z 629 > 447.1 for LPV, 721.18 > 268.02 for RTV and m/z 747.22 > 322.03 for the internal standard (IS). The limit of quantification was 1 ng/mL for both analytes in all matrices. The method was linear in the studied range (1-2000 ng/mL for LPV and 1-200 ng/mL for RTV), with r2 > 0.99 for each drug, and the run time was 4.5 min. The intra-assay precisions (%) were in the ranges of 0.1-14.2 (LPV) and 0.4-12.7 (RTV), the inter-assay precisions were in the ranges of 2.8-15.3 (LPV) and 1.1-12.8 (RTV) and the intra-and inter-assay recoveries were >85% for both drugs. The extraction efficiencies were 73.5-118.4% for LPV and 74.4-126.2% for RTV. The analytical method was applied to measure LPV and RTV concentrations in blood plasma (total and unbound fraction), saliva and semen of six HIV+ individuals under stable treatment with Kaletra soft gel capsules. The results were consistent with previously published data.