Urine tenofovir and dried blood spot tenofovir diphosphate concentrations and viraemia in people taking efavirenz and dolutegravir-based antiretroviral therapy.

OBJECTIVE: We aimed to determine whether urine tenofovir (TFV) and dried blood spot (DBS) tenofovir diphosphate (TFV-DP) concentrations are associated with concurrent HIV viraemia. DESIGN: Cross-sectional study among people with HIV (PWH) receiving tenofovir disoproxil fumarate (TDF)-based antiretroviral therapy (ART). METHODS: We used dual tandem liquid chromatography and mass spectrometry to measure urine TFV and DBS TFV-DP concentrations, and evaluated their associations with concurrent viraemia at least 1000 copies/ml using logistic regression models. In exploratory analyses, we used receiver operating curves (ROCs) to estimate optimal urine TFV and DBS TFV-DP thresholds to predict concurrent viraemia. RESULTS: Among 124 participants, 68 (54.8%) were women, median age was 39 years [interquartile range (IQR) 34-45] and 74 (59.7%) were receiving efavirenz versus 50 (40.3%) receiving dolutegravir. Higher concentrations of urine TFV [1000 ng/ml increase, odds ratio (OR) 0.97 95% CI 0.94-0.99, P  = 0.005] and DBS TFV-DP (100 fmol/punch increase, OR 0.76, 95% CI 0.67-0.86, P  < 0.001) were associated with lower odds of viraemia. There was evidence that these associations were stronger among people receiving dolutegravir than among people receiving efavirenz (urine TFV, P  = 0.072; DBS TFV-DP, P  = 0.003). Nagelkerke pseudo- R2 for the DBS TFV-DP models was higher for the urine TFV models, demonstrating a stronger relationship between DBS TFV-DP and viraemia. Among people receiving dolutegravir, a DBS TFV-DP concentration of 483 fmol/punch had 88% sensitivity and 85% specificity to predict concurrent viraemia ≥1000 copies/ml. CONCLUSION: Among PWH receiving TDF-based ART, urine TFV concentrations, and in particular DBS TFV-DP concentrations, were strongly associated with concurrent viraemia, especially among people receiving dolutegravir.

Feasibility, Acceptability and Appropriateness of MedViewer: A Novel Hair-Based Antiretroviral Real-Time Clinical Monitoring Tool Providing Adherence Feedback to Patients and Their Providers.

Antiretroviral therapy (ART) adherence is key to achieving viral load suppression and ending the HIV epidemic but monitoring and supporting adherence using current interventions is challenging. We assessed the feasibility, acceptability and appropriateness of MedViewer (MV), a novel intervention that provides real-time adherence feedback for patients and providers using infra-red matrix-assisted laser desorption electrospray ionization (IR-MALDESI) for mass spectrometry imaging of daily ART concentrations in patients' hair. We used mixed methods to feasibility test MV at a busy Infectious Diseases (ID) clinic, enrolling 16 providers and 36 patients. Providers underwent standardized training; patients and providers watched an 8-min informational video about MV. We collected patient and provider data at baseline and within 24 h of clinic visits and, with patients, approximately 1 month after clinic visits. MedViewer was feasible, liked by patients and providers, and perceived to help facilitate adherence conversations and motivate patients to improve adherence. Trial Registration: NCT04232540.

Comparison of efavirenz levels in blood and hair with pharmacy refills as measures of adherence and predictors of viral suppression among people living with HIV in Nigeria.

BACKGROUND: Strategies to support adherence are constrained by the lack of tools to objectively monitor medication intake in low-resource settings. Pharmacologic measures are objective, but pharmacy refill data is more accessible and cost-efficient. This study compared short-term and long-term efavirenz (EFV) drug levels with pharmacy refill adherence data (PRA) and evaluated their ability to predict viral suppression among people living with HIV in Nigeria. METHODS: Paired hair and dried blood spot (DBS) samples were obtained from 91 adults living with HIV receiving 600 mg EFV-based antiretroviral therapy (ART) and EFV concentrations were measured via validated methods using liquid-chromatography-mass-spectrometry. PRA was estimated from pharmacy records, based on the number of days a patient collected medication before or after the scheduled pick-up date. PRA was categorized into ≤ 74%, 75-94% and ≥ 95%, defined as poor, medium and high adherence, respectively. HIV viral loads closest to the hair sampling time (within 6 months) were also abstracted. Receiver Operating Characteristics (ROC) curve analyses compared the ability of adherence metrics to predict viral suppression. RESULTS: Based on PRA, 81% of participants had high adherence while 11% and 8% had medium and poor adherence, respectively. The median (IQR) EFV concentrations were 6.85 ng/mg (4.56-10.93) for hair and 1495.6 ng/ml (1050.7-2365.8) for DBS. Of the three measures of adherence, hair EFV concentration had the highest Area Under Curve (AUC) to predict viral suppression. Correlations between EFV concentrations in DBS and hair with PRA were positive (r = 0.12, P = 0.27 and r = 0.21, P = 0.05, respectively) but not strong. CONCLUSIONS: EFV concentrations in hair were the strongest predictor of viral suppression and only weakly correlated with pharmacy refill adherence data in Nigeria. This study suggests that resource-limited settings may benefit from objective adherence metrics to monitor and support adherence.

Development of Spray-Dried Cyclodextrin-Based Pediatric Anti-HIV Formulations.

The human immunodeficiency virus (HIV) impacts up to 37 million people globally, of which 1.8 million are children. To date, there is no cure for HIV, although treatment options such as antiretroviral therapy (ART) are available. ART, which involves a patient taking a combination of antiretrovirals, is being used to treat HIV clinically. Despite the effectiveness of ART, there is currently no palatable pediatric formulation to treat HIV in children, which has hindered patient compliance and overall treatment efficacy. In addition, anti-HIV therapeutics are often poorly water-soluble, and hence have poor bioavailability. In the present study, we developed a pediatric-friendly formulation for anti-HIV therapeutics with improved dissolution characteristics of the therapeutic agents. Lopinavir (LPV) and ritonavir (RTV), available as FDA-approved fixed-dose combination products, were chosen as model ART drugs, and the formulation and processing parameters of spray-dried cyclodextrin (CD)-based LPV and RTV complexes were studied. Results showed that the spray-dried complexes exhibited enhanced dissolution profiles in comparison to pure drugs, particularly spray-dried ß-CD complexes, which showed the most favorable dissolution profiles. This current formulation with enhanced dissolution and taste-masking ability through the use of cyclodextrin has the potential to address the unmet need for the development of suitable pediatric formulations.

Islatravir in combination with doravirine for treatment-naive adults with HIV-1 infection receiving initial treatment with islatravir, doravirine, and lamivudine: a phase 2b, randomised, double-blind, dose-ranging trial.

BACKGROUND: Islatravir is a nucleoside reverse transcriptase translocation inhibitor in development for the treatment and prevention of HIV-1 infection. We aimed to assess the efficacy and safety of islatravir-based regimens for the treatment of HIV-1. METHODS: We did a phase 2b, randomised, double-blind, comparator-controlled, dose-ranging trial at 24 clinics or hospitals in four countries (Chile, France, the UK, and the USA). Treatment-naive adults (≥18 years) with plasma HIV-1 RNA concentrations of at least 1000 copies per mL, CD4 T-cell counts of at least 200 cells per mL, and a calculated creatinine clearance of at least 50 mL/min (all within 60 days before study treatment) were eligible for inclusion. Participants were randomly assigned (1:1:1:1) with a block size of four via an interactive voice and web response system to receive oral treatment with one of three doses of islatravir (0·25 mg, 0·75 mg, or 2·25 mg) plus doravirine (100 mg) and lamivudine (300 mg) or to doravirine (100 mg) plus lamivudine (300 mg) plus tenofovir disoproxil fumarate (TDF; 300 mg) once daily with placebo (part 1). Treatment groups were stratified according to screening HIV-1 RNA concentration (≤100 000 copies per mL or >100 000 copies per mL). After at least 24 weeks of treatment, participants taking islatravir who achieved an HIV-1 RNA concentration lower than 50 copies per mL switched to a two-drug regimen of islatravir and doravirine (part 2). All participants and study investigators were masked to treatment in part 1; in part 2, the islatravir dose was masked to all participants and investigators, but the other drugs were given open label. The primary efficacy outcomes were the proportions of participants with an HIV-1 RNA concentration lower than 50 copies per mL at weeks 24 and 48 (US Food and Drug Administration snapshot approach). The primary safety outcomes were the number of participants experiencing adverse events and the number of participants discontinuing study drug owing to adverse events. All participants who received at least one dose of any study drug were included in the analyses. This trial is ongoing, but closed to enrolment of new participants; herein, we report study findings through 48 weeks of treatment. This trial is registered with ClinicalTrials.gov, NCT03272347. FINDINGS: Between Nov 27, 2017, and April 25, 2019, 121 participants (mean age 31 years [SD 10·9], 112 [93%] male, 92 [76%] white, 27 [22%] with HIV-1 RNA concentration >100 000 copies per mL) were randomly assigned: 29 to the 0·25 mg, 30 to the 0·75 mg, and 31 to the 2·25 mg islatravir groups, and 31 to the doravirine, lamivudine, and TDF group. At week 24, 26 (90%) of 29 participants in the 0·25 mg islatravir group, 30 (100%) of 30 in the 0·75 mg islatravir group, and 27 (87%) of 31 in the 2·25 mg islatravir group achieved HIV-1 RNA concentrations lower than 50 copies per mL compared with 27 (87%) of 31 in the doravirine plus lamivudine plus TDF group (difference 2·8%, 95% CI -14·9 to 20·4, for the 0·25 mg islatravir group; 12·9%, -1·6 to 27·5, for the 0·75 mg islatravir group; and 0·3%, -17·9 to 18·5, for the 2·25 mg islatravir group). At week 48, these data were 26 (90%) of 29 in the 0·25 mg islatravir group, 27 (90%) of 30 in the 0·75 mg islatravir group, and 24 (77%) of 31 in the 2·25 mg islatravir group compared with 26 (84%) of 31 in the doravirine plus lamivudine plus TDF group (difference 6·1%, 95% CI -12·4 to 24·4, for the 0·25 mg islatravir group; 6·2%, -12·2 to 24·6, for the 0·75 mg islatravir group; and -6·1%, -27·1 to 14·8, for the 2·75 mg islatravir group). 66 (73%) of participants in the islatravir groups combined and 24 (77%) of those in the doravirine plus lamivudine plus TDF group reported at least one adverse event. Two participants in the 2·25 mg islatravir group and one participant in the doravirine plus lamivudine plus TDF group discontinued owing to an adverse event. No deaths were reported up to week 48. INTERPRETATION: Treatment regimens containing islatravir and doravirine showed antiviral efficacy and were well tolerated regardless of dose. Doravirine in combination with islatravir has the potential to be a potent two-drug regimen that warrants further clinical development. FUNDING: Merck, Sharp, & Dohme Corp, a subsidiary of Merck & Co., Inc.

Tenofovir and emtricitabine concentrations in hair are comparable between individuals on tenofovir disoproxil fumarate versus tenofovir alafenamide-based ART.

Tenofovir disoproxil fumarate (TDF) in combination with emtricitabine (FTC) is the backbone for both human immunodeficiency virus (HIV) treatment and pre-exposure prophylaxis (PrEP) worldwide. Tenofovir alafenamide (TAF) with FTC is increasingly used in HIV treatment and was recently approved for PrEP among men-who-have-sex-with-men. TDF and TAF are both metabolized into tenofovir (TFV). Antiretrovirals in plasma are taken up into hair over time, with hair levels providing a long-term measure of adherence. Here, we report a simple, robust, highly sensitive, and validated high-performance liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS)-based analytical method for analyzing TFV and FTC from individuals on either TDF/FTC or TAF/FTC in small hair samples. TFV/FTC are extracted from ~5 mg hair and separated on a column using a gradient elution. The lower quantification limits are 0.00200 (TFV) and 0.0200 (FTC) ng/mg hair; the assay is linear up to 0.400 (TFV) and 4.00 (FTC) ng/mg hair. The intra-day and inter-day coefficients of variance (CVs) are 5.39-12.6% and 6.40-13.5% for TFV and 0.571-2.45% and 2.45-5.16% for FTC. TFV concentrations from participants on TDF/FTC-based regimens with undetectable plasma HIV RNA were 0.0525 ± 0.0295 ng/mg, whereas those from individuals on TAF/FTC-based regimens were 0.0426 ± 0.0246 ng/mg. Despite the dose of TFV in TDF being 10 times that of TAF, hair concentrations of TFV were not significantly different for those on TDF versus TAF regimens. Pharmacological enhancers (ritonavir and cobicistat) did not boost TFV concentrations in hair. In summary, we developed and validated a sensitive analytical method to analyze TFV and FTC in hair and found that hair concentrations of TFV were essentially equivalent among those on TDF and TAF.

Short Communication: Higher Tenofovir Concentrations in Hair Are Associated with Decreases in Viral Load and Not Self-Reported Adherence in HIV-Infected Adolescents with Second-Line Virological Treatment Failure.

Objective methods of measuring antiretroviral adherence are limited. We assessed the relationship between tenofovir disoproxil fumarate (TDF) hair concentrations, self-reported adherence, and virological outcomes in HIV-infected adolescents in Harare, Zimbabwe. HIV-infected adolescents on atazanavir/ritonavir-based second-line treatment for >6 months with viral load (VL) ≥1,000 copies/mL were randomized to either modified directly administered antiretroviral therapy (mDAART) or standard of care. Hair and VL samples were collected at baseline and after 90 days. Treatment outcome was defined as TDF concentrations in hair. Virological suppression was defined as VL <1,000 copies/mL. Thirty-four adolescents had TDF concentrations measured at baseline and follow-up. Mean (median); range age was 16 (16); 13-18 years and 53% were females. Nineteen (56%) were randomized to mDAART. Mean (SD); range TDF concentrations were 0.03 (0.04); 0-0.17 ng/mg hair and 0.06 (0.06); 0-0.3 ng/mg hair at baseline and follow-up, respectively. Higher TDF concentrations were associated with decreased VL [regression coefficient (RC) 0.8; 95% confidence interval (CI) 0.7-1.0; p = .008] and mDAART (RC 0.5; 95% CI 0.3-1.0; p = .04), but were not associated with self-reported adherence and virological suppression (VL <1,000 copies/mL). Higher TDF hair concentrations were observed with virological decrease and an adherence intervention. Hair antiretroviral concentrations could be useful in triggering adherence interventions among adolescents with second-line virological failure.

"I wish to remain HIV negative": Pre-exposure prophylaxis adherence and persistence in transgender women and men who have sex with men in coastal Kenya.

BACKGROUND: Transgender women (TGW) and men who have sex with men (MSM) in sub-Saharan Africa have high HIV acquisition risks and can benefit from daily pre-exposure prophylaxis (PrEP). We assessed PrEP adherence by measuring tenofovir-diphosphate (TFV-DP) levels and explore motives for PrEP persistence in TGW and MSM. METHODS: Participants were enrolled in a one-year PrEP programme and made quarterly visits irrespective of whether they were still using PrEP. At their month 6 visit, participants provided a dried blood spot to test for TFV-DP levels; protective levels were defined as those compatible with ≥4 pills per week (700-1249 fmol/punch). Before TFV-DP levels were available, a sub-set of these participants were invited for an in-depth interview (IDI). Semi-structured IDI topic guides were used to explore motives to uptake, adhere to, and discontinue PrEP. IDI data were analyzed thematically. RESULTS: Fifty-three participants (42 MSM and 11 TGW) were enrolled. At month 6, 11 (20.7%) participants (8 MSM and 3 TGW) were lost to follow up or stopped taking PrEP. Any TFV-DP was detected in 62.5% (5/8) of TGW vs. 14.7% of MSM (5/34, p = 0.01). Protective levels were detected in 37.5% of TGW (3/8), but not in any MSM. Nineteen IDI were conducted with 7 TGW and 9 MSM on PrEP, and 1 TGW and 2 MSM off PrEP. Unplanned or frequent risky sexual risk behaviour were the main motives for PrEP uptake. Among participants on PrEP, TGW had a more complete understanding of the benefits of PrEP. Inconsistent PrEP use was attributed to situational factors. Motives to discontinue PrEP included negative reactions from partners and stigmatizing healthcare services. CONCLUSION: While MSM evinced greater adherence challenges in this PrEP programme, almost 40% of TGW were protected by PrEP. Given high HIV incidences in TGW these findings hold promise for TGW PrEP programming in the region.

Rapid, user-friendly, and inexpensive detection of azidothymidine.

Strict adherence to highly active antiretroviral therapy (HAART) is very important to improve the quality of life for HIV-positive patients to reduce new infections and determine treatment success. Azidothymidine (AZT) is an antiretroviral drug commonly used in HAART treatment. In this research, an "add, mix, and measure" assay was developed to detect AZT within minutes. Three different probes designed to release fluorophores when samples containing AZT are added were synthesized and characterized. The limit of detection to AZT in simulated urine samples was determined to be 4 µM in 5 min for one of the probes. This simple and rapid point-of-care test could potentially be used by clinicians and health care workers to monitor the presence of AZT in low resource settings.

The effect of depot medroxyprogesterone acetate on tenofovir alafenamide in rhesus macaques.

Prevention of HIV infection and unintended pregnancies are public health priorities. In sub-Saharan Africa, where HIV prevalence is highest, depot medroxyprogesterone acetate (DMPA) is widely used as contraception. Therefore, understanding potential interactions between DMPA and antiretrovirals is critical. Here, we use a macaque model to investigate the effect of DMPA on the pharmacology of the antiretroviral tenofovir alafenamide (TAF). Female rhesus macaques received 30 mg of DMPA (n = 9) or were untreated (n = 9). Macaques received a human equivalent dose of TAF (1.5 mg/kg) orally by gavage. Tenofovir (TFV) and TFV-diphosphate (TFV-DP) were measured in blood, secretions, and tissues over 72 h. The median area under the curve (AUC0-72h) values for TFV-DP in peripheral blood mononuclear cells were similar in DMPA-treated (6991 fmol*h/106 cells) and untreated controls (5256 fmol*h/106 cells) (P = 0.174). Rectal tissue TFV-DP concentrations from DMPA+ animals [median: 20.23 fmol/mg of tissue (range: 4.94-107.95)] were higher than the DMPA- group [median: below the limit of quantification (BLOQ-11.92)], (P = 0.019). TFV-DP was not detectable in vaginal tissue from either group. A high-dose DMPA treatment in macaques was associated with increased rectal TFV-DP levels, indicating a potential tissue-specific drug-drug interaction. The lack of detectable TFV-DP in the vaginal tissue warrants further investigation of PrEP efficacy with single-agent TAF products. DMPA did not affect systemic TAF metabolism, with similar PBMC TFV-DP in both groups, suggesting that DMPA use should not alter the antiviral activity of TAF.

Extent of In Utero Transfer of Tenofovir From Mother to Fetus: A Paired Analysis of Hair Specimens Collected at Birth From a Cohort in the United States.

Understanding in utero transfer of antiretrovirals is critical for interpreting safety. Hair levels measure cumulative exposure. We measured tenofovir (TFV) concentrations in hair at delivery among women living with human immunodeficiency virus receiving TFV disoproxil fumarate-based treatment and their infants, using liquid chromatography-tandem mass spectrometry. Among 103 mother-infant pairs, the mean log10 ratio of infant-to-maternal TFV levels was 1.08 (95% confidence interval, .97-1.20). TFV transfer was 60% lower from mothers who had preterm compared with term deliveries and 42% lower from mothers who had cesarean compared with vaginal deliveries. Like prior studies assessing transfer via short-term measures (plasma, cord blood, amniotic fluid), we found high cumulative transfer using hair.

LC-MS/MS Quantification of Nevirapine and Its Metabolites in Hair for Assessing Long-Term Adherence.

The adherence assessment based on the combination of nevirapine (NVP) and its two metabolites (2-hydroxynevirapine and 3-hydroxynevirapine) would more comprehensively and accurately reflect long-term adherence than that of a single prototype. This study aimed to develop a specific, sensitive and selective method for simultaneous detection of the three compounds in hair and explore whether there was consistency among the three compounds in assessing long-term adherence. Furthermore, 75 HIV-positive patients who were taking the NVP drug were randomly recruited and divided into two groups (high-and low-adherence group). All participants self-reported their days of oral drug administration per month and provided their hair strands closest to the scalp at the region of posterior vertex. The concentrations of three compounds in the hair were determined using a developed LC-MS/MS method in multiple reaction monitoring. This method showed good performances in limit of quantification and accuracy with the recoveries from 85 to 115% and in precision with the intra-day and inter-day coefficients of variation within 15% for the three compounds. The population analysis revealed that patients with high-adherence showed significantly higher concentrations than those with low-adherence for all three compounds. There were significantly moderate correlations of nevirapine with 2-hydroxynevirapine and 3-hydroxynevirapin and high correlation between 2-hydroxynevirapine and 3-hydroxynevirapin. The two NVP's metabolites showed high consistency with NVP in evaluating long-term adherence.

Efficacy of silk fibroin biomaterial vehicle for in vivo mucosal delivery of Griffithsin and protection against HIV and SHIV infection ex vivo.

INTRODUCTION: The majority of new HIV infections occur through mucosal transmission. The availability of readily applicable and accessible platforms for anti-retroviral (ARV) delivery is critical for the prevention of HIV acquisition through sexual transmission in both women and men. There is a compelling need for developing new topical delivery systems that have advantages over the pills, gels and rings, which currently fail to guarantee protection against mucosal viral transmission in vulnerable populations due to lack of user compliance. The silk fibroin (SF) platform offers another option that may be better suited to individual circumstances and preferences to increase efficacy through user compliance. The objective of this study was to test safety and efficacy of SF for anti-HIV drug delivery to mucosal sites and for viral prevention. METHODS: We formulated a potent HIV inhibitor Griffithsin (Grft) in a mucoadhesive silk fibroin (SF) drug delivery platform and tested the application in a non-human primate model in vivo and a pre-clinical human cervical and colorectal tissue explant model. Both vaginal and rectal compartments were assessed in rhesus macaques (Mucaca mulatta) that received SF (n = 4), no SF (n = 7) and SF-Grft (n = 11). In this study, we evaluated the composition of local microbiota, inflammatory cytokine production, histopathological changes in the vaginal and rectal compartments and mucosal protection after ex vivo SHIV challenge. RESULTS: Effective Grft release and retention in mucosal tissues from the SF-Grft platform resulted in protection against HIV in human cervical and colorectal tissue as well as against SHIV challenge in both rhesus macaque vaginal and rectal tissues. Mucoadhesion of SF-Grft inserts did not cause any inflammatory responses or changes in local microbiota. CONCLUSIONS: We demonstrated that in vivo delivery of SF-Grft in rhesus macaques fully protects against SHIV challenge ex vivo after two hours of application and is safe to use in both the vaginal and rectal compartments. Our study provides support for the development of silk fibroin as a highly promising, user-friendly HIV prevention modality to address the global disparity in HIV infection.

Development and validation of RP-HPLC method for simultaneous estimation of docetaxel and ritonavir in PLGA nanoparticles.

OBJECTIVES: The main objective of the present study was to develop and validate simple, precise, sensitive and accurate RP-HPLC method for the simultaneous estimation of docetaxel (DTX) and ritonavir (RTV) in PLGA nanoparticles (PLGA-NPs). METHODS: The DTX and RTV co-loaded PLGA-NPs were developed by the nanoprecipitation technique. The RP-HPLC method was developed by using (Agilent Compact LC-1220) and Zorbax Eclipse plus C18 column (150×4.6mm, 3.5µm, Agilent). Finally, the developed method was validated according to the international conference on harmonization (ICH) guidelines. RESULTS: The chromatographic separations of DTX and RTV with good resolutions have been achieved by using the mobile phase Acetonitrile: Water (60:40 v/v) containing 0.1% v/v of orthophosphoric acid at a flow rate of 1.0mL/min, injection volume of 25µL, and at 239nm wavelengths. The validated method found to be linear in the range of 0.001-100µg/mL for DTX and RTV. Detection and quantification limits for DTX were found to be 0.7 and 2.31µg/mL respectively and for RTV it is 0.3 and 2.87µg/mL respectively. The % RSD was found to be less than 2% revealing the precision of the developed method. Besides, the recovery rate was observed close to 100% for both the drugs confirming the accuracy of the method. Minor alterations in the chromatographic conditions have revealed robustness and ruggedness of the developed method. CONCLUSION: The developed analytical method is simple, precise, sensitive, and reproducible which can be used for the simultaneous estimation of DTX and RTV in the PLGA-NPs.

Factors influencing hair lamivudine concentration among people living with HIV in Guangxi, China.

BACKGROUND: Hair antiretroviral concentration has served as an innovative and objective measure of antiretroviral adherence. However, some factors (for example, pharmacokinetics and hair characteristics) may contribute to the variability of hair antiretroviral concentration that may threaten the validity and reliability of the hair measure as a biomarker of adherence. This study aimed to examine the potential factors that may influence the measure of hair antiretroviral concentration. METHODS: Hair samples from a cohort of 372 people living with HIV (PLHIV) receiving lamivudine (300 mg/day) in Guangxi, China. Lamivudine concentration was analysed using liquid chromatography-tandem mass spectrometry. Multivariable linear regression was used to evaluate the associations of hair lamivudine concentration with age, sex, ethnicity, height, weight, body mass index, duration of HIV diagnosis, duration of current regimen, dosing schedule, concomitant antiretroviral medications, frequency of hair washing, hair care products use, hair cosmetic treatment and self-reported adherence. RESULTS: Multivariable models revealed that frequency of hair washing (ß=-0.221, P=0.001), dosing schedule (ß=0.141, P=0.036) and self-reported adherence (ß=0.160, P=0.002) were associated with hair lamivudine concentration. CONCLUSIONS: We observed that, among those potential factors, hair lamivudine concentration was influenced by frequency of hair washing and dosing schedule. Therefore, frequency of hair washing and dosing schedule should be considered in future research using hair lamivudine concentration as a measure of lamivudine exposure and biomarker of adherence.

Comparing self-reported medication adherence measures with hair antiretroviral concentration among people living with HIV in Guangxi, China.

BACKGROUND: Antiretroviral adherence is essential to HIV treatment efficacy. Various self-reported measures are commonly used for assessing antiretroviral adherence. Limited data are available regarding the validity of those self-reported measures in comparison with long-term objective biomarkers of adherence measures such as hair measures. METHODS: Self-reported adherence (frequency, percentage, and visual analog scale [VAS]) and hair tenofovir concentration were evaluated at a single time point from 268 people living with HIV in China. The responses to each of three self-reported measures were converted into percentage and then dichotomized as "optimal" (100%) vs. "suboptimal" (less than 100%) adherence. Two composite adherence scores (CAS) were created from the three self-reported measures: (1) an overall adherence was the average percentage of the three self-reported measures; (2) responses were termed optimal adherence if participants reporting optimal adherence in all three self-reported measures, while were termed suboptimal adherence. Hair tenofovir concentration was also dichotomized as "optimal" (above the limit of quantitation, 36 pg/mg) vs. "suboptimal" adherence (blow 36 pg/mg). Spearman correlation, kappa statistics, and logistic regression analysis were used to calculate the correlations, agreements, and predictions of self-reported measures with hair measure, respectively. RESULTS: Overall adherence, but any of the three self-reported adherence, was correlated with hair tenofovir concentration (r = 0.13, p < 0.05). Self-reported optimal adherence in VAS and CAS measures were agreed with and predicted optimal adherence assessed by hair measure (Kappa = 0.107, adjusted OR = 1.88, 95% CI 1.03-3.45; Kappa = 0.109, adjusted OR = 1.80, 95% CI 1.02-3.18; all p < 0.05, respectively). CONCLUSION: VAS may be a good individual self-reported measure for antiretroviral adherence, and CAS may be a good composite self-reported measure for antiretroviral adherence.

Simple thin layer chromatography-ultraviolet spectrophotometric method for quality assessment of binary fixed-dose-combinations of lamivudine/tenofovir disoproxil fumarate and lamivudine/zidovudine in tablet formulations.

Antiretroviral fixed-dose-combination drugs are best assayed with high-performance liquid chromatography, or liquid chromatography-tandem mass spectrometry. However, most scientists in developing nations have no access to these expensive instruments. A more affordable quantitative technique is the use of ultraviolet-visible spectroscopy-where often the absorption spectra of these antiretrovirals are overlapping; thus complex derivative methodologies are required for quantification. A simple, rapid, and accurate thin layer chromatography-ultraviolet spectrophotometric method for the quantification of binary mixtures of lamivudine, zidovudine, and tenofovir-disoproxil-fumarate in tablet formulations was developed. Lamivudine/tenofovir-disoproxil-fumarate and lamivudine/zidovudine were extracted and separated on glass thin-layer chromatography plates. Drugs were identified in ultraviolet light at 254 nm and quantified in acidic medium using ultraviolet spectrophotometry. The retardation factors were 0.43, 0.79, and 0.81 for lamivudine, tenofovir-disoproxil-fumarate, and zidovudine, respectively, with corresponding absorption maxima at 270, 260, and 265 nm. Linearity ranged from 1 to 40 µg/mL for all drugs (R = 0.9998-0.9999), while recovery studies were 95.10-102.11% and amount in formulations ranged from 97.99 ± 0.63 to 101.47 ± 2.39%. The paired t-test (n = 5) indicated no significant difference between the proposed and high-performance liquid chromatography methods, hence comparable and can be used as an alternative method in routine quality determination of antiretroviral medicines.

Factors Related to Hair Antiretroviral Concentration: A Systematic Review of Global Literature.

Assessment of antiretroviral (ARV) concentration in hair (hair antiretroviral concentration [HAC]) is one of the latest non-invasive innovations for measuring long-term ARV adherence. We performed a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines to identify the factors that may affect the validity and reliability of HAC. This review included 25 studies that reported data on the associations of hair concentrations of 10 ARVs with 22 potential factors related to HAC. Notwithstanding scarce data and some inconsistencies, the data from existing studies suggested that (1) HAC was associated with hair types, hair segment position, housing, illegal drugs use, high-risk sexual behaviors, renal function, and genetic factors; (2) HAC was not associated with race/ethnicity, location of sample, ARV side effects, length of ARV treatment, smoking, alcohol use, orange consumption, depression, or anthropometry characteristics; and (3) the relationships of HAC with natural hair color, hair treatment, age, sex, dosing schedule, and liver function need further study. This review of factors related to HAC informed the design, analysis, and interpretation of the future HIV treatment and HIV prevention research utilizing hair concentrations of various ARVs as a biomarker of ARV adherence.

HPLC-MS/MS method for the simultaneous quantification of dolutegravir, elvitegravir, rilpivirine, darunavir, ritonavir, raltegravir and raltegravir-ß-d-glucuronide in human plasma.

Therapeutic drug monitoring (TDM) is essential in the optimization of antiretroviral (ARV) treatments. In this work, we describe a new method for the simultaneous quantification of six molecules: the three novel ARV agents dolutegravir (DTG), elvitegravir (ELV) and rilpivirine (RPV), the first integrase inhibitor raltegravir (RAL) and its major metabolite the raltegravir-ß-d-glucuronide (RAL-GLU), an protease inhibitor darunavir (DRV) and its booster ritonavir (RTV) in human plasma. The drugs were extracted from 100 µL of plasma by a simple method of protein precipitation using acetonitrile. The separation was carried out on a Kinetex phehyl-hexyl column using a phase mobile composed of 55 % of water (0.05 % formic acid,v/v) and 45 % of methanol (0.05 % formic acid,v/v). The flow rate was set at 0.5 mL/min. The calibration ranged from 60 to 15000 ng/mL for DRV, from 20 to 5000 ng/mL for DTG and ELV, from 10 to 2500 ng/mL for RAL, RAL-GLU, RTV and RPV. The proposed method was validated with a good precision (inter- and intra-day CV% inferior to 12.3 %) and a good accuracy (inter- and intra-day bias between -9.9 % and 10 %) for all the analytes. The proposed method is simple, reliable and suitable for therapeutic drug monitoring (TDM) and for pharmacokinetics studies.

Antiretroviral Concentration in Hair as a Measure for Antiretroviral Medication Adherence: A Systematic Review of Global Literature.

This review aims to validate hair antiretroviral concentration (HAC) as a measure for antiretroviral medication adherence. This review included 31 studies that analyzed a total of 11 ARV drugs in four different drug classes. The associations between HAC and non-pharmacokinetic measures were generally lower than the association between HAC and other pharmacokinetic measures: the correlation coefficients (r) ranged from - 0.20 to 0.38 for self-report or pill counts and 0.20 to 0.85 for electronic drug monitoring; HAC and other pharmacokinetic measures were positively correlated with the correlation coefficients (r) ranging from 0.20 to 0.72, 0.34 to 0.86, 0.50 to 0.85 for antiretroviral concentration in plasma, peripheral blood mononuclear cells, and dried blood spots, respectively. HAC was one of the strongest independent predictors of virologic responses. HAC of tenofovir was significantly associated with renal toxicity in large sample studies. This review suggests that HAC is a valid biomarker of antiretroviral medication adherence.