Determinants of sustained viral suppression in HIV-infected patients with self-reported poor adherence to antiretroviral therapy

HIV care outcomes among transgender persons with HIV infection in the United States, 2006-2021

OBJECTIVES

HIV prevalence is an estimated 14% among transgender women (TW) and 3% among transgender men (TM). HIV care is vital for viral suppression but is hindered by transphobia and HIV stigma. We assessed HIV care outcomes among transgender persons (TG) with HIV in the United States.

DESIGN

Systematic review and meta-analysis of peer-reviewed journal articles.

METHODS

We searched multiple electronic databases and Centers for Disease Control and Prevention's HIV Prevention Research Synthesis database for 2006-September 2020. Eligible reports were US-based studies that included TG and reported HIV care outcomes. Random-effects models were used to calculate HIV care outcome rates. The protocol is registered with PROSPERO (CRD42018079564).

RESULTS

Few studies reported outcomes for TM; therefore, only TW meta-analysis results are reported. Fifty studies were identified having low-to-medium risk-of-bias scores. Among TW with HIV, 82% had ever received HIV care; 72% were receiving care, and 83% of those were retained in HIV care. Sixty-two percent were currently virally suppressed. Among those receiving HIV care or antiretroviral therapy (ART), 67% were virally suppressed at last test. Sixty-five percent were linked to HIV care 3 months or less after diagnosis. Seventy-one percent had ever been prescribed ART. Approximately 66% were taking ART, and 66% were ART-adherent. Only 56% were currently adherent the previous year.

CONCLUSIONS

HIV care outcomes for TW were not ideal, and research gaps exists for TM. High heterogeneity was observed; therefore, caution should be taken interpreting the findings. Integrating transgender-specific health needs are needed to improve outcomes of transgender persons across the HIV care continuum.

The role of pharmacogenetics in Efficacy and safety of protease inhibitor based therapy in human immunodeficiency virus type (HIV) infection

Antiretroviral therapy has markedly reduced morbidity and mortality for persons living with human immunodeficiency virus (HIV). HIV can now be classified as a chronic disease; until a cure is found, patients are likely to require life-long therapy. However, despite these undoubted advances, there are many issues that need to be resolved, including the problems associated with long-term efficacy and toxicity. Moreover, pharmacotherapy of patients infected with HIV is challenging because a great number of comorbidities increase polypharmacy and the risk for drug-drug interactions. There is considerable interindividual variability in patient outcomes in terms of drug disposition, drug efficacy and adverse events. The basis of these differences is multifactorial, but host genetics are believed to play a significant part. HIV-infected population consists of ethnically diverse individuals on complex and potentially toxic antiretroviral regimens on a long-term basis. These individuals would benefit greatly from predictive tests that identify the most durable regimens. Pharmacogenetics holds that promise. Thus, detailed understanding of the metabolism and transport of antiretrovirals and the influence of genetics on these pathways is important. To this end, this review provides an up-to-date overview of the metabolism of antiHIV therapeutics of the protease inhibitors Lopinavir and Ritonavir and the impact of genetic variation in drug metabolism and transport on the treatment of HIV.

Substance Use Predicts Sustained Viral Suppression in a Community Cohort of Sexual and Gender Minority Youth Living with HIV

Retention in care and sustained viral suppression are integral outcomes in the care continuum for people living with HIV (PLWH) and HIV prevention; however, less is known about how substance use predicts sustained viral suppression over time. This study seeks to examine the predictive effects of substance use on sustained viral suppression in a sample of cisgender sexual minority men and gender minority PLWH (n = 163) drawn from a longitudinal sample in the Chicago area collected 2015-2019. Using data from 3 visits separated by 6 months, participants were coded persistently detectable, inconsistently virally suppressed, and consistently virally suppressed (< 40 copies/mL at all visits). Multinomial logistic regressions were utilized. About 40% of participants had sustained viral suppression. In multinomial logistic regressions, CUDIT-R predicted persistent detectable status and stimulant use was associated with inconsistent viral suppression. Substance use may create challenges in achieving sustained viral suppression, which has important implications for care and prevention.

Emergence of Drug Resistance in the Swiss HIV Cohort Study Under Potent Antiretroviral Therapy Is Observed in Socially Disadvantaged Patients

BACKGROUND

The rate of acquired human immunodeficiency virus type 1 (HIV-1) drug resistance (ADR) has fallen dramatically since introduction of combined antiretroviral therapy (cART) in Switzerland. However, clinical experience indicates that there are still patients at risk of newly acquiring drug resistance despite having access to cART. Here, we characterized risk factors for ADR, to improve patient care and prevent emergence of drug resistance and treatment failure.

METHODS

We performed a case-control study to identify risk factors for ADR in all patients starting their first cART in the Swiss HIV Cohort Study (SHCS) since 1996. The SHCS is highly representative and includes >75% of patients receiving ART in Switzerland. To this end, we implemented a systematic medical chart review to obtain more detailed information on additional parameters, which are not routinely collected in the SHCS. The collected data were analyzed using univariable and multivariable conditional logistic regression.

RESULTS

We included in our study 115 cases and 115 matched controls. Unemployment (multivariable odds ratio [mOR], 2.9 [95% confidence interval {CI}, 1.3-6.4]; P = .008), African origin (mOR, 3.0 [95% CI, 1.0-9.2]; P = .047), comedication with anti-infectives (mOR, 3.7 [95% CI, 1.0-12.6]; P = .045), and symptoms of mental illness (mOR, 2.6 [95% CI, 1.2-5.5]; P = .012) were associated with ADR in the multivariable model.

CONCLUSIONS

Although ADR has become very rare with cART due to new potent therapies, patients in socially challenging life situations or presenting with mental health issues are at higher risk for drug resistance. Prompt identification and adequate support of these patients before ADR will prevent treatment failure and HIV-1 transmission.

Meta-analysis of the associations of CYP2B6-516G>T polymorphisms with efavirenz-induced central nervous system side effects and virological outcome in HIV-infected adults

Clinical data on the relationships of cytochrome P450 (CYP2) B6 516G>T polymorphisms with efavirenz-induced central nervous system (CNS) side effects and virological response in HIV-infected adults are controversial. We sought to analyze the associations by meta-analysis. To identify eligible studies, we systematically searched PubMed, Embase, ScienceDirect, and Web of Science. The strength of the associations was measured by odds ratio (OR) and effect size (ES) with 95% confidence interval (CI). Seventeen studies comprising a total of 3598 HIV-infected adults were included. The results showed that the CYP2B6-516 GG genotype was significantly associated with a decreased risk of efavirenz-induced CNS side effects compared with the GT and TT genotypes (GG + GT vs. TT: OR = 0.60, 95% CI = 0.41-0.87, P = 0.006; GG vs. GT + TT: OR = 0.68, 95% CI = 0.51-0.91, P = 0.008; GG vs. GT: OR = 0.70, 95% CI = 0.51-0.94, P = 0.018), and there was no significant association between the genetic variants GT and TT (GT vs. TT: OR = 0.82, 95% CI = 0.54-1.26, P = 0.372). However, there was no significant association between CYP2B6-516 GG and GT + TT genotypes in virological response (GT + TT vs. GG: ES = 1.06, 95% CI = 0.95-1.18, P = 0.321; OR = 1.01, 95% CI = 0.65-1.58, P = 0.963). Taken together, our results demonstrated that compared with the normal efavirenz clearance genotype CYP2B6-516 GG, the slow and very slow efavirenz clearance genotypes GT and TT were significantly associated with an increased risk of efavirenz-induced CNS side effects but not an increased virological response. To promote the tolerance of efavirenz, it is better to adjust the dosage of efavirenz according to the polymorphisms of CYP2B6-516 in HIV-infected adults.

HIV care continuum among newly diagnosed student and non-student youths between 2012 and 2016 in Hangzhou, China

BACKGROUND

Youths are disproportionally affected by the human immunodeficiency virus (HIV) infection. We aimed to assess anti-retroviral therapy (ART) initiation and viral suppression rates among student and non-student youths in Hangzhou, China.

METHODS

Data were taken from the Chinese HIV/acquired immune deficiency syndrome Comprehensive Response Information Management System. Youths aged 15 to 24 years who were newly diagnosed with HIV between 2012 and 2016 and were living in Hangzhou were included in the study. Comparisons between student and non-student youths were made for ART initiation within 30 days, 90 days, and 12 months of HIV diagnosis, and the viral suppression rate at 12 months of HIV diagnosis and at 12 months of ART initiation.

RESULTS

A total of 707 cases met inclusion criteria, 29.6% of which were students and 70.4% were non-student youths. The student group had a higher proportion of ART initiation compared with the non-student group within 30 days of diagnosis (45.5% vs. 37.0%, P = 0.044), and a slightly higher but not statistically significant proportion at 90 days (67.0% vs. 62.7%), and 12 months (83.7% vs. 78.5%) of HIV diagnosis. ART initiation within 30 days improved from <15% in 2012 to over 65% in 2016 in both groups, and ART initiation within 90 days improved from <30% in 2012 to >90% in 2016. A smaller proportion of students experienced viral suppression compared with the non-student group (9.6% vs. 17.1%, P = 0.011) at 12 months after HIV diagnosis, but the suppression rate was similar at 12 months of ART initiation (69.9% vs. 71.1%, P = 0.743).

CONCLUSIONS

ART initiation in both student and non-student youths has significantly improved between 2012 and 2016. However, the viral suppression rate remained unacceptably low at 12 months of HIV diagnosis in both student and non-student groups. Specific intervention strategies must be taken to address this challenge.

Virologic failure in HIV-positive adolescents with perfect adherence in Uganda: a cross-sectional study

Background

Adolescents living with human immunodeficiency virus (HIV) die owing to acquired immune deficiency syndrome (AIDS)-related causes more than adults. Although viral suppression protects people living with HIV from AIDS-related illnesses, little is known about viral outcomes of adolescents in sub-Saharan Africa where the biggest burden of deaths is experienced. This study aimed to identify the factors associated with viral load suppression among HIV-positive adolescents (10-19 years) receiving antiretroviral therapy (ART) in Uganda.

Methods

We conducted a cross-sectional study among school-going, HIV-positive adolescents on ART from August to September 2016. We recruited 238 adolescents who underwent ART at a public health facility and had at least one viral load result recorded in their medical records since 2015. We collected the data of patients' demographics and treatment- and clinic-related factors using existing medical records and questionnaire-guided face-to-face interviews. For outcome variables, we defined viral suppression as < 1000 copies/mL. We used multivariate logistic regression to determine factors associated with viral suppression.

Results

We analyzed the data of 200 adolescents meeting the inclusion criteria. Viral suppression was high among adolescents with good adherence > 95% (adjusted odds ratio [AOR] 2.73, 95% confidence interval [95% CI, 1.09 to 6.82). However, 71% of all adolescents who did not achieve viral suppression were also sufficiently adherent (adherence > 95%). Regardless of adherence status, other risk factors for viral suppression at the multivariate level included having a history of treatment failure (AOR 0.26, 95% CI, 0.09 to 0.77), religion (being Anglican [AOR 0.19, 95% CI, 0.06 to 0.62] or Muslim [AOR 0.17, 95% CI, 0.05 to 0.55]), and having been prayed for (AOR 0.38, 95% CI, 0.15 to 0.96).

Conclusion

More than 70% of adolescents who experienced virologic failure were sufficiently adherent (adherence > 95). Adolescents who had unsuppressed viral loads in their initial viral load were more likely to experience virologic failure upon a repeat viral load regardless of their adherence level or change of regimen. The study also shows that strong religious beliefs exist among adolescents. Healthcare provider training in psychological counseling, regular and strict monitoring of adolescent outcomes should be prioritized to facilitate early identification and management of drug resistance through timely switching of treatment regimens to more robust combinations.

Comprehensive Pharmacokinetic, Pharmacodynamic and Pharmacogenetic Evaluation of Once-Daily Efavirenz 400 and 600 mg in Treatment-Naïve HIV-Infected Patients at 96 Weeks: Results of the ENCORE1 Study

Background

ENCORE1 demonstrated non-inferiority of daily efavirenz 400 mg (EFV400) versus 600 mg (EFV600) to 96 weeks in treatment-naïve, HIV-infected adults but concerns regarding lower EFV400 concentrations remained. Therefore, relationships between EFV pharmacokinetics (PK) and key genetic polymorphisms with 96-week efficacy and safety were investigated.

Methods

Relationships between EFV PK parameters and single nucleotide polymorphisms (SNP; CYP2B6,CYP2A6, CYP3A4, NR1I3, NR1I2, ABCB1) with plasma HIV-RNA (pVL) <200 copies/mL and EFV discontinuation and adverse events at 96 weeks were explored. Receiver operating characteristic curve analysis evaluated the predictability of mid-dose interval (C₁₂) cutoffs and 96-week pVL.

Results

A total of 606 patients (32 % female; 37 % African, 33 % Asian; n = 311 EFV400, n = 295 EFV600) were included. EFV PK parameters, including C₁₂, were not associated with pVL <200 copies/mL at 96 weeks (odds ratio [OR] 5.25, 95 % confidence interval [CI] 0.41–67.90, p = 0.204). Lower risk of CNS-related adverse events was associated with CYP2B6 983TC/CC (OR 0.35, 95 % CI 0.15–0.81, p = 0.015) and higher risk was associated with CYP2B6 15582CT/TT and ABCB1 3435TT (OR 1.46, 95 % CI 1.02–2.09, p = 0.040; OR 2.31, 95 % CI 1.33–4.02, p = 0.003, respectively). Discontinuation due to adverse events (clinician decision) was independently associated with dose (OR 2.54, 95 % CI 1.19–5.43, p = 0.016). C₁₂ between 0.47 and 0.76 mg/L provided sensitivity/specificity >90 % (100 %/92.3 to 98.9 %/92.3 %) for achieving pVL <200 copies/mL at 96 weeks.

Conclusions

A higher rate of EFV-related adverse events and discontinuations due to these events for EFV600 were not driven by polymorphisms assessed. Although a single threshold concentration associated with HIV suppression may be clinically useful, it was not viable for ENCORE1. Implementation of EFV400 would improve toxicity management whilst still maintaining good efficacy.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-015-0360-5) contains supplementary material, which is available to authorized users.

Baseline CD4 Count and Adherence to Antiretroviral Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

In light of recent changes to antiretroviral treatment (ART) guidelines of the World Health Organization and ongoing concerns about adherence with earlier initiation of ART, we conducted a systematic review of published literature to review the association between baseline (pre-ART initiation) CD4 count and ART adherence among adults enrolled in ART programs worldwide.

METHODS

We performed a systematic search of English language original studies published between January 1, 2004 and September 30, 2015 using Medline, Web of Science, LILACS, AIM, IMEMR, and WPIMR databases. We calculated the odds of being adherent at higher CD4 count compared with lower CD4 count according to study definitions and pooled data using random effects models.

RESULTS

Twenty-eight articles were included in the review and 18 in the meta-analysis. The odds of being adherent was marginally lower for patients in the higher CD4 count group (pooled odds ratio, 0.90; 95% confidence interval, 0.84 to 0.96); however, the majority of studies found no difference in the odds of adherence when comparing CD4 count strata. In analyses restricted to comparisons above and below a CD4 count of 500 cells per microliter, there was no difference in adherence (pooled odds ratio, 1.01; 95% confidence interval: 0.97 to 1.05).

CONCLUSIONS

This review was unable to find consistent evidence of differences in adherence according to baseline CD4 count. Although this is encouraging for the new recommendations to treat all HIV-positive individuals irrespective of CD4 count, there is a need for additional high-quality studies, particularly among adults initiating ART at higher CD4 cell counts.

Patient-Reported Barriers to Adherence to Antiretroviral Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

Maintaining high levels of adherence to antiretroviral therapy (ART) is a challenge across settings and populations. Understanding the relative importance of different barriers to adherence will help inform the targeting of different interventions and future research priorities.

METHODS AND FINDINGS

We searched MEDLINE via PubMed, Embase, Web of Science, and PsychINFO from 01 January 1997 to 31 March 2016 for studies reporting barriers to adherence to ART. We calculated pooled proportions of reported barriers to adherence per age group (adults, adolescents, and children). We included data from 125 studies that provided information about adherence barriers for 17,061 adults, 1,099 children, and 856 adolescents. We assessed differences according to geographical location and level of economic development. The most frequently reported individual barriers included forgetting (adults 41.4%, 95% CI 37.3%-45.4%; adolescents 63.1%, 95% CI 46.3%-80.0%; children/caregivers 29.2%, 95% CI 20.1%-38.4%), being away from home (adults 30.4%, 95% CI 25.5%-35.2%; adolescents 40.7%, 95% CI 25.7%-55.6%; children/caregivers 18.5%, 95% CI 10.3%-26.8%), and a change to daily routine (adults 28.0%, 95% CI 20.9%-35.0%; adolescents 32.4%, 95% CI 0%-75.0%; children/caregivers 26.3%, 95% CI 15.3%-37.4%). Depression was reported as a barrier to adherence by more than 15% of patients across all age categories (adults 15.5%, 95% CI 12.8%-18.3%; adolescents 25.7%, 95% CI 17.7%-33.6%; children 15.1%, 95% CI 3.9%-26.3%), while alcohol/substance misuse was commonly reported by adults (12.9%, 95% CI 9.7%-16.1%) and adolescents (28.8%, 95% CI 11.8%-45.8%). Secrecy/stigma was a commonly cited barrier to adherence, reported by more than 10% of adults and children across all regions (adults 13.6%, 95% CI 11.9%-15.3%; children/caregivers 22.3%, 95% CI 10.2%-34.5%). Among adults, feeling sick (15.9%, 95% CI 13.0%-18.8%) was a more commonly cited barrier to adherence than feeling well (9.3%, 95% CI 7.2%-11.4%). Health service-related barriers, including distance to clinic (adults 17.5%, 95% CI 13.0%-21.9%) and stock outs (adults 16.1%, 95% CI 11.7%-20.4%), were also frequently reported. Limitations of this review relate to the fact that included studies differed in approaches to assessing adherence barriers and included variable durations of follow up. Studies that report self-reported adherence will likely underestimate the frequency of non-adherence. For children, barriers were mainly reported by caregivers, which may not correspond to the most important barriers faced by children.

CONCLUSIONS

Patients on ART face multiple barriers to adherence, and no single intervention will be sufficient to ensure that high levels of adherence to treatment and virological suppression are sustained. For maximum efficacy, health providers should consider a more triaged approach that first identifies patients at risk of poor adherence and then seeks to establish the support that is needed to overcome the most important barriers to adherence.

Adherence to Antiretroviral Therapy Among Children Living with HIV in South India

Adherence to ART, fundamental to treatment success, has been poorly studied in India. Caregivers of children attending HIV clinics in southern India were interviewed using structured questionnaires. Adherence was assessed using a visual analogue scale representing past-month adherence and treatment interruptions >48 h during the past 3 months. Clinical features, correlates of adherence and HIV-1 viral-load were documented. Based on caregiver reports, 90.9 % of the children were optimally adherent. In multivariable analysis, experiencing ART-related adverse effects was significantly associated with suboptimal adherence (p = 0.01). The proportion of children who experienced virological failure was 16.5 %. Virological failure was not linked to suboptimal adherence. Factors influencing virological failure included running out of medications (p = 0.002) and the child refusing to take medications (p = 0.01). Inclusion of drugs with better safety profiles and improved access to care could further enhance outcomes.

Four days a week or less on appropriate anti-HIV drug combinations provided long-term optimal maintenance in 94 patients: the ICCARRE project

Short, intraweekly cycles of anti-HIV combinations have provided intermittent, effective therapy (on 48 patients) (1). The concept is now extended to 94 patients on treatment, 4 days per week or less, over a median of 2.7 discontinuous treatment years per patient. On suppressive combinations, 94 patients volunteered to treatment, 5 and 4 days per week, or reduced stepwise to 4, 3, 2, and 1 days per week in 94, 84, 66, and 12 patients, respectively, on various triple, standard, antiviral combinations, or nonregistered, quadruple, antiviral combinations. Ninety-four patients on treatment 4 days per week aggregated 165 intermittent treatment years; no viral breakthrough was observed over 87 average treatment weeks per patient, 63 of 94 having passed 2.5 intermittent treatment years on any of the antiviral combinations prescribed. On the hyperintermittent treatment of 3, 2, and 1 days per week, HIV RNA surged >50 copies, 4 weeks apart, in 18 instances (6.8 viral escapes/100 hyperdiscontinuous maintenance years). Viral escapes could have been a result of erratic adherence (EA) to regimen or follow-up (3 patients)--drug taken at half of the daily recommended dosage (8 patients) and/or overlooked archival-resistant HIVs from antecedent treatment failures (6 patients). Aside from the above circumstances, HIV unexpectedly rebounded in 3 patients on 2 days per week treatment and 1 patient on 1 day per week treatment, posting 2.2 intrinsic viral escapes/100 highly discontinuous treatment years. All 18 escapes were eventually reversed by 7 days per week salvage combinations, and 11 of 18 patients have been back for a second course of intermittent therapy, 4 days per week or less. Both cell-activation markers on the surface of T lymphocytes and cell-bound HIV DNA levels remained stable or declined. CD4/CD8 ratios rose to ≥1 in 35% of patients, whereas CD4 counts went ≥500/µl in 75%. These values were previously 7 and 40%, respectively, on 7 days per week therapy. In our aging, long, HIV-enduring, multitreated patient cohort, treatment 4 days per week and less over 421 intermittent treatment years reduced prescription medicines by 60%--equivalent to 3 drug-free/3 virus-free remission year per patient--actually sparing €3 million on just 94 patients at the cost of 2.2 intrinsic viral failure/100 hyperintermittent treatment years. At no risk of viral escape, maintenance therapy, 4 days per week, would quasiuniversally offer 40% cuts off of current overprescriptions.

Adherence in the treatment of patients with extensively drug-resistant tuberculosis and HIV in South Africa: a prospective cohort study

OBJECTIVE

Extensively drug-resistant tuberculosis (XDR-TB)/HIV coinfection is difficult to treat with frequent adverse drug reactions and associated with high mortality. Adherence to antiretroviral therapy (ARV) and second-line TB medications may reduce mortality, prevent amplification of drug resistance, and improve outcomes.

METHODS

Prospective cohort study of XDR-TB patients on treatment in KwaZulu-Natal, South Africa. Adherence to ARV and TB medications was assessed separately at baseline and monthly. Knowledge, attitudes, and beliefs were assessed at baseline. Optimal adherence was defined as self-report of taking all pills in the previous 7 days; missing any pills was defined as suboptimal adherence. Primary outcome was optimal adherence 6 months after initiation of XDR-TB treatment to TB medications, ARV, and both ("dual adherence").

RESULTS

One hundred four XDR-TB patients (79.8% HIV coinfected, 84.3% on ARV at enrollment) were enrolled and followed monthly (median 8 visits; interquartile range: 4-12). Six-month optimal adherence was higher for ARV (88.2%) than TB medications (67.7%) (P < 0.001). Low educational attainment, male gender, and year of enrollment were independently associated with dual suboptimal adherence. At baseline, participants indicated that XDR-TB was curable (76.0%), HIV and TB were linked (81.7%), and ARV improves TB outcomes (72.1%). Baseline knowledge, attitudes, and beliefs did not predict subsequent adherence.

CONCLUSIONS

Medication adherence was significantly higher for ARV than for TB medications in this cohort. Short-course treatment regimens for drug-resistant TB with lower pill burden may increase adherence and improve outcomes in XDR-TB/HIV. Programmatic support for dual adherence is critical in the treatment of drug-resistant TB and HIV.

Impact of an electronic medical record on the incidence of antiretroviral prescription errors and HIV pharmacist reconciliation on error correction among hospitalized HIV-infected patients

BACKGROUND

Previous review of admissions from 2009-2011 in our institution found a 35.1% error rate in antiretroviral (ART) prescribing, with 55% of errors never corrected. Subsequently, our institution implemented a unified electronic medical record (EMR) and we developed a medication reconciliation process with an HIV pharmacist. We report the impact of the EMR on incidence of errors and of the pharmacist intervention on time to error correction.

METHODS

Prospective medical record review of HIV-infected patients hospitalized for >24 h between 9 March 2013 and 10 March 2014. An HIV pharmacist reconciled outpatient ART prescriptions with inpatient orders within 24 h of admission. Prescribing errors were classified and time to error correction recorded. Error rates and time to correction were compared to historical data using relative risks (RR) and logistic regression models.

RESULTS

43 medication errors were identified in 31/186 admissions (16.7%). The incidence of errors decreased significantly after EMR (RR 0.47, 95% CI 0.34, 0.67). Logistic regression adjusting for gender and race/ethnicity found that errors were 61% less likely to occur using the EMR (95% CI 40%, 75%; P<0.001). All identified errors were corrected, 65% within 24 h and 81.4% within 48 h. Compared to historical data where only 31% of errors were corrected in <24 h and 55% were never corrected, errors were 9.4× more likely to be corrected within 24 h with HIV pharmacist intervention (P<0.001).

CONCLUSIONS

Use of an EMR decreased the error rate by more than 50% but despite this, ART errors remained common. HIV pharmacist intervention was key to timely error correction.

Antiretroviral medication prescribing errors are common with hospitalization of HIV-infected patients

OBJECTIVES

Errors in prescribing antiretroviral therapy (ART) often occur with the hospitalization of HIV-infected patients. The rapid identification and prevention of errors may reduce patient harm and healthcare-associated costs.

METHODS

A retrospective review of hospitalized HIV-infected patients was carried out between 1 January 2009 and 31 December 2011. Errors were documented as omission, underdose, overdose, duplicate therapy, incorrect scheduling and/or incorrect therapy. The time to error correction was recorded. Relative risks (RRs) were computed to evaluate patient characteristics and error rates.

RESULTS

A total of 289 medication errors were identified in 146/416 admissions (35%). The most common was drug omission (69%). At an error rate of 31%, nucleoside reverse transcriptase inhibitors were associated with an increased risk of error when compared with protease inhibitors (RR 1.32; 95% CI 1.04-1.69) and co-formulated drugs (RR 1.59; 95% CI 1.19-2.09). Of the errors, 31% were corrected within the first 24 h, but over half (55%) were never remedied. Admissions with an omission error were 7.4 times more likely to have all errors corrected within 24 h than were admissions without an omission. Drug interactions with ART were detected on 51 occasions. For the study population (n = 177), an increased risk of admission error was observed for black (43%) compared with white (28%) individuals (RR 1.53; 95% CI 1.16-2.03) but no significant differences were observed between white patients and other minorities or between men and women.

CONCLUSION

Errors in inpatient ART were common, and the majority were never detected. The most common errors involved omission of medication, and nucleoside reverse transcriptase inhibitors had the highest rate of prescribing error. Interventions to prevent and correct errors are urgently needed.

Underlying genetic structure impacts the association between CYP2B6 polymorphisms and response to efavirenz and nevirapine

OBJECTIVE

CYP2B6 variation predicts pharmacokinetic characteristics of its substrates. Consideration for underlying genetic structure is critical to protect against spurious associations with the highly polymorphic CYP2B6 gene.

DESIGN

The effect of CYP2B6 variation on response to its substrates, nonnucleoside reverse transcriptase inhibitors (NNRTIs), was explored in the Women's Interagency HIV Study.

METHODS

Five putative functional polymorphisms were tested for associations with virologic suppression within 1 year after NNRTI initiation in women naive to antiretroviral agents (n = 91). Principal components were generated to control for population substructure. Logistic regression was used to test the joint effect of rs3745274 and rs28399499, which together indicate slow, intermediate, and extensive metabolizers.

RESULTS

Rs3745274 was significantly associated with virologic suppression [odds ratio = 3.61, 95% confidence interval (CI) 1.16-11.22, P trend = 0.03]; the remaining polymorphisms tested were not significantly associated with response. Women classified as intermediate and slow metabolizers were 2.90 (95% CI 0.79-12.28) and 13.44 (95% CI 1.66 to infinity) times as likely to achieve virologic suppression compared to extensive metabolizers after adjustment for principal components (P trend = 0.005). Failure to control for genetic ancestry resulted in substantial confounding of the relationship between the metabolizer phenotype and treatment response.

CONCLUSION

The CYP2B6 metabolizer phenotype was significantly associated with virologic response to NNRTIs; this relationship would have been masked by simple adjustment for self-reported ethnicity. Given the appreciable genetic heterogeneity that exists within self-reported ethnicity, these results exemplify the importance of characterizing underlying genetic structure in pharmacogenetic studies. Further follow-up of the CYP2B6 metabolizer phenotype is warranted, given the potential clinical importance of this finding.