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Biomedical subjects

Julio S G Montaner

Publications and source records attributed to Julio S G Montaner.

At least 19 recordsLinked to original sources
PubMed2007

Rates of inappropriate antiretroviral prescription among injection drug users.

BACKGROUND: Although the survival benefits of antiretroviral therapy (ART) for the treatment of HIV infection are well established, the clinical management of HIV disease continues to present major challenges. There are particular concerns regarding access to appropriate HIV treatment among HIV-infected injection drug users (IDU). METHODS: In a prospective cohort study of HIV-infected IDU in Vancouver, Canada, we examined initial ART regimens vis-à-vis the provincial government's therapeutic guidelines at the time ART was initiated. Briefly, there have been four sets of guidelines: Era 1 (1992 to November 1995; double-drug (dual NRTIs) ART for patients with a CD4 cell count of 350 or less); Era 2 (December 1995 to May 1996; double-drug therapy for patients with a CD4+ cell count of 500 or less); Era 3 (June 1996 to June 1997; triple-drug therapy (dual NRTIs with a PI or NNRTI) for patients who had a plasma viral load of > 100,000 HIV-1 RNA copies/mL; dual therapy with two NRTIs for those with a plasma viral load of 5,000 to 100,000 HIV-1 RNA copies/mL); Era 4 (since July 1997; universal use of triple drug therapy as first-line treatment). RESULTS: Between May 1996 and May 2003, 431 HIV-infected individuals were enrolled into the cohort. By May 31, 2003, 291 (67.5%) individuals had initiated ART. We noted instances of inappropriate antiretroviral prescription in each guideline era, with 9 (53%) in Era 1, 3 (12%) in Era 2, 22 (28%) in Era 3, and 23 (15%) in Era 4. Of the 57 subjects who received an inappropriate ART regimen initially, 14 never received the appropriate therapy; among the remaining 43, the median time to the initiation of a guideline-appropriate ART regimen was 12 months (inter-quartile range 5-20). CONCLUSION: The present study identified measurable rates of guideline-inappropriate ART prescription for patients who were injection drug users. Rates were highest in the era of dual therapy, although high rates persisted into the triple-therapy era. As therapeutic guidelines continue to evolve, it is critical that mechanisms be put in place to ensure prescription of ART combinations for IDU that are consistent with current expert recommendations.

Journal Article↗
PubMed2006

HIV seroprevalence among participants at a Supervised Injection Facility in Vancouver, Canada: implications for prevention, care and treatment.

North America's first government sanctioned medically supervised injection facility (SIF) was opened during September 2003 in Vancouver, Canada. This was in response to a large open public drug scene, high rates of HIV and hepatitis C transmission, fatal drug overdoses, and poor health outcomes among the city's injection drug users. Between December 2003 and April 2005, a representative sample of 1,035 SIF participants were enrolled in a prospective cohort that required completing an interviewer-administered questionnaire and providing a blood sample for HIV testing. HIV infection was detected in 170/1007 (17%) participants and was associated with Aboriginal ethnicity (adjusted Odds Ratio [aOR], 2.70, 95% Confidence Interval [95% CI], 1.84-3.97), a history of borrowing used needles/syringes (aOR, 2.0, 95% CI, 1.37-2.93), previous incarceration (aOR, 1.87, 95% CI, 1.11-3.14), and daily injection cocaine use (aOR, 1.42, 95% CI, 1.00-2.03). The SIF has attracted a large number of marginalized injection drug users and presents an excellent opportunity to enhance HIV prevention through education, the provision of sterile injecting equipment, and a supervised environment to self-inject. In addition, the SIF is an important point of contact for HIV positive individuals who may not be participating in HIV care and treatment.

Journal Article↗
PubMed2006

Performance of immunologic responses in predicting viral load suppression: implications for monitoring patients in resource-limited settings.

BACKGROUND: World Health Organization (WHO) guidelines for the use of antiretroviral therapy (ART) in resource-limited settings state that CD4 cell counts may be used to indicate when ART regimens should be changed because of treatment failure. The performance of immunologic monitoring for this purpose has not been evaluated, however. METHODS: Participants aged > or =18 years from the British Columbia HIV/AIDS Drug Treatment Program who had CD4 cell counts < or =200 cells/microL or an AIDS diagnosis at baseline had CD4 cell counts measured at 6 and 12 months after treatment initiation. Logistic regression analysis was used to calculate sensitivity, specificity, and positive and negative predictive values for immunologic responses in terms of predicting failure to achieve 2 viral load measurements < 500 copies/mL within 1 year. RESULTS: Viral load suppression occurred in 674 (60%) of 1125 subjects. Using no increase in CD4 cell counts at 6 months as a definition of treatment failure had a sensitivity of 34%, specificity of 94%, positive predictive value of 75%, and negative predictive value of 71% for predicting failure to achieve virologic suppression. Using 12-month CD4 cell count values, the measurements were 35%, 95%, 79%, and 73%, respectively. CONCLUSION: Immunologic criteria to predict which patients have not achieved virologic suppression results in significant misclassification of therapeutic responses.

Anti-HIV Agents↗
PubMed2006

A simple, dynamic measure of antiretroviral therapy adherence predicts failure to maintain HIV-1 suppression.

BACKGROUND: High levels of antiretroviral therapy adherence are important for human immunodeficiency virus type 1 (HIV-1) suppression, yet the magnitude of adherence required to maintain it is less well characterized. Furthermore, methods to accommodate changes in adherence over time are lacking. In the present study, our objective was to determine the magnitude of antiretroviral therapy adherence needed to maintain HIV-1 suppression by use of a time-updated adherence measure that has the potential to be of use in a clinical setting. METHODS: We examined a population-based cohort of HIV-1-infected subjects > or =18 years of age, residing in British Columbia, Canada, who started receiving antiretroviral therapy between 1 August 1996 and 30 September 2003, who had at least 2 consecutive viral loads <500 copies/mL and who had prescriptions filled at least 3 times during a follow-up period ending 30 September 2004. Virological failure was defined as the second of 2 consecutive viral loads >1000 copies/mL. Cox proportional hazards model was used to determine the relationship between virological failure and refill-based, time-updated surrogate measure of adherence. RESULTS: Among the 1634 participants > or =18 years of age who initiated triple combination therapy during the study, 606 virological failure events were identified. In multivariate analyses, subjects with < or =95% adherence were 1.66 (95% confidence interval, 1.38-2.01) times more likely to experience virological failure than those with >95% adherence. CONCLUSIONS: The highest levels of antiretroviral therapy adherence are associated with higher rates of maintained virological suppression. This simple, dynamic surrogate measure of adherence overcomes the limitation of single-point-in-time calculations of adherence and may be useful in real time to determine whether an individual is exhibiting incomplete adherence.

Adult↗
PubMed2006

Injection drug users' perceptions regarding use of a medically supervised safer injecting facility.

BACKGROUND: In recent years, there has been increased interest in supervised safer injecting facilities (SIF) as a strategy to reduce the harms of illicit drug use; however, little work has been done to assess drug users' satisfaction with this service. This study was undertaken to explore injection drug users' experiences and opinions regarding North America's first SIF in Vancouver, Canada. METHODS: Injection drug users (IDU) were randomly recruited from within the Vancouver SIF and invited to enroll in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort. For the present study, participants were then surveyed regarding their experiences and beliefs regarding the SIF. RESULTS: Of 1082 IDU surveyed, 809 (75%) reported that their injecting behavior had changed as a result of using the SIF. Among these individuals, 80% indicated that the SIF had resulted in less rushed injecting, 71% indicated that the SIF had led to less outdoor injecting and 56% reported less unsafe syringe disposal. The three most common features always or usually limiting IDU's use of the SIF were: travel to the SIF (12%), limited operating hours (7%), and waiting times to access the SIF (5%). When asked in what ways the SIF might be improved, the three most common suggestions were: longer hours of operation (53%), addition of a washroom (51%), and reduced waiting times (46%). CONCLUSIONS: Many IDU reported changes in their injecting behaviors that have important implications for community and public health. Addressing a number of programmatic issues related to operating hours and waiting times, and the provision of additional amenities within SIF, may help to further improve their impact.

Adult↗
PubMed2006

Treatment for adult HIV infection: 2006 recommendations of the International AIDS Society-USA panel.

CONTEXT: Guidelines for antiretroviral therapy are important for clinicians worldwide given the complexity of the field and the varied clinical situations in which these agents are used. The International AIDS Society-USA panel has updated its recommendations as warranted by new developments in the field. OBJECTIVE: To provide physicians and other human immunodeficiency virus (HIV) clinicians with current recommendations for the use of antiretroviral therapy in HIV-infected adults in circumstances for which there is relatively unrestricted access to drugs and monitoring tools. The recommendations are centered on 4 key issues: when to start antiretroviral therapy; what to start; when to change; and what to change. Antiretroviral therapy in special circumstances is also described. DATA SOURCES AND STUDY SELECTION: A 16-member noncompensated panel was appointed, based on expertise in HIV research and patient care internationally. Data published or presented at selected scientific conferences from mid 2004 through May 2006 were identified and reviewed by all members of the panel. DATA EXTRACTION AND SYNTHESIS: Data that might change previous guidelines were identified and reviewed. New guidelines were drafted by a writing committee and reviewed by the entire panel. CONCLUSIONS: Antiretroviral therapy in adults continues to evolve rapidly, making delivery of state-of-the-art care challenging. Initiation of therapy continues to be recommended in all symptomatic persons and in asymptomatic persons after the CD4 cell count falls below 350/microL and before it declines to 200/microL. A nonnucleoside reverse transcriptase inhibitor or a protease inhibitor boosted with low-dose ritonavir each combined with 2 nucleoside (or nucleotide) reverse transcriptase inhibitors is recommended with choice being based on the individual patient profile. Therapy should be changed when toxicity or intolerance mandate it or when treatment failure is documented. The virologic target for patients with treatment failure is now a plasma HIV-1 RNA level below 50 copies/mL. Adherence to antiretroviral therapy in the short-term and the long-term is crucial for treatment success and must be continually reinforced.

Adult↗
PubMed2006

Complementary and alternative medicine use in British Columbia--a survey of HIV positive people on antiretroviral therapy.

In 2002, the British Columbia (BC) Centre for Excellence in HIV/AIDS collected final detailed data on complementary and alternative medicine (CAM) use in their HIV treatment program. This cross-sectional study of 682 participants examines types and determinants of CAM use in this program, and examines adverse effects associated with CAM use and antiretroviral therapy (ART). Among the 47% ever CAM users in the included population, vitamins/minerals (81%), meditation/yoga (36%), massage (31%), marijuana (30%), dietary supplements (24%), and herbal medicines (19%), were most commonly used. Multivariate analysis indicated CAM users were less likely to have low education (AOR=0.51), more likely to be unemployed (AOR=1.52), more likely to have been on ART longer (AOR=1.19), and more likely to experience objective, action-requiring (OA) side effects (AOR=1.45). CAM use is common. Both patients and health professionals should be aware of potential toxicities and drug interactions related to the use of CAM and HIV/AIDS treatment.

Adult↗
PubMed2006

Neighborhood and HIV infection among IDU: place of residence independently predicts HIV infection among a cohort of injection drug users.

This study was undertaken to investigate geographic residence in Vancouver's Downtown Eastside (DTES), Canada's poorest urban neighborhood, as an environmental risk factor for HIV infection among a cohort of injection drug users. HIV incidence rates were examined using Kaplan-Meier methods, and Cox proportional hazards regression was used to determine independent risk factors for HIV seroconversion. After intensive multivariate adjustment, DTES residence remained an independent predictor of HIV seroconversion (relative hazard=2.0, 95% CI: 1.4-3.0, p<0.001). These findings indicate the need for a greater recognition among policy-makers of geographic location as a risk factor for HIV incidence in urban settings and the need for further research to determine why place contributes so greatly to HIV risk. The findings also mark a need for prevention interventions to be appropriately targeted towards high-risk neighborhoods.

Adult↗
PubMed2006

Evaluating methamphetamine use and risks of injection initiation among street youth: the ARYS study.

Many Canadian cities are experiencing ongoing infectious disease and overdose epidemics among injection drug users (IDU). These health concerns have recently been exacerbated by the increasing availability and use of methamphetamine. The challenges of reducing health-related harms among IDU have led to an increased recognition that strategies to prevent initiation into injection drug use must receive renewed focus. In an effort to better explore the factors that may protect against or facilitate entry into injection drug use, the At Risk Youth Study (ARYS) has recently been initiated in Vancouver, Canada. The local setting is unique due to the significant infrastructure that has been put in place to reduce HIV transmission among active IDU. The ARYS study will seek to examine the impact of these programs, if any, on non-injection drug users. In addition, Vancouver has been the site of widespread use of methamphetamine in general and has seen a substantial increase in the use of crystal methamphetamine among street youth. Hence, the ARYS cohort is well positioned to examine the harms associated with methamphetamine use, including its potential role in facilitating initiation into injection drug use. This paper provides some background on the epidemiology of illicit drug use among street youth in North America and outlines the methodology of ARYS, a prospective cohort study of street youth in Vancouver, Canada.

Journal Article↗
PubMed2006

Aboriginal status is a prognostic factor for mortality among antiretroviral naïve HIV-positive individuals first initiating HAART.

BACKGROUND: Although the impact of Aboriginal status on HIV incidence, HIV disease progression, and access to treatment has been investigated previously, little is known about the relationship between Aboriginal ethnicity and outcomes associated with highly active antiretroviral therapy (HAART). We undertook the present analysis to determine if Aboriginal and non-Aboriginal persons respond differently to HAART by measuring HIV plasma viral load response, CD4 cell response and time to all-cause mortality. METHODS: A population-based analysis of a cohort of antiretroviral therapy naïve HIV-positive Aboriginal men and women 18 years or older in British Columbia, Canada. Participants were antiretroviral therapy naïve, initiated triple combination therapy between August 1, 1996 and September 30, 1999. Participants had to complete a baseline questionnaire as well as have at least two follow-up CD4 and HIV plasma viral load measures. The primary endpoints were CD4 and HIV plasma viral load response and all cause mortality. Cox proportional hazards models were used to determine the association between Aboriginal status and CD4 cell response, HIV plasma viral load response and all-cause mortality while controlling for several confounder variables. RESULTS: A total of 622 participants met the study criteria. Aboriginal status was significantly associated with no AIDS diagnosis at baseline (p = 0.0296), having protease inhibitor in the first therapy (p = 0.0209), lower baseline HIV plasma viral load (p < 0.001), less experienced HIV physicians (P = 0.0133), history of IDU (p < 0.001), not completing high school (p = 0.0046), and an income of less than $10,000 per year (p = 0.0115). Cox proportional hazards models controlling for clinical characteristics found that Aboriginal status had an increased hazard of mortality (HR = 3.12, 95% CI: 1.77-5.48) but did not with HIV plasma viral load response (HR = 1.15, 95% CI: 0.89-1.48) or CD4 cell response (HR = 0.95, 95% CI: 0.73-1.23). CONCLUSION: Our study demonstrates that HIV-infected Aboriginal persons accessing HAART had similar HIV treatment response as non-Aboriginal persons but have a shorter survival. This study highlights the need for continued research on medical interventions and behavioural changes among HIV-infected Aboriginal and other marginalized populations.

Journal Article↗
PubMed2006

Impact of baseline viral load and adherence on survival of HIV-infected adults with baseline CD4 cell counts > or = 200 cells/microl.

BACKGROUND: Baseline plasma HIV RNA levels > 100 000 copies/ml have been associated with elevated mortality rates after the initiation of HAART. There is uncertainty regarding the optimal strategy for patients with high plasma HIV RNA but CD4 cell count > or = 200 cells/microl. OBJECTIVE: To evaluate the impact of baseline plasma HIV RNA on survival among patients with CD4 cell counts > or = 200 cells/microl. METHODS: Patients were stratified by plasma HIV RNA, CD4 cell count and adherence level. Mortality rates were evaluated using Kaplan-Meier methods and Cox regression. RESULTS: Among 1166 patients initiating HAART with a CD4 cell count > or = 200 cells/microl, a baseline HIV RNA > or = 100 000 copies/ml was statistically associated with elevated mortality among non-adherent patients (log-rank P = 0.032), but not for adherent patients (log-rank P = 0.690). In a multivariate Cox model comparing patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA < 100 000 copies/ml, the mortality rate was statistically similar among patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA > or = 100 000 copies/ml (relative hazard, 1.21; 95% confidence interval, 0.89-1.65; P = 0.232). CONCLUSION: HIV RNA > or = 100 000 copies/ml was only associated with mortality among HIV-infected patients initiating HAART with CD4 cell counts > or= 200 cells/microl if the patients were non-adherent.

Adolescent↗
PubMed2006

Efficacy, safety and pharmacokinetics of once-daily saquinavir soft-gelatin capsule/ritonavir in antiretroviral-naive, HIV-infected patients.

CONTEXT: Once-daily HIV treatment regimens are being used in clinical practice with the objective of improving patient acceptance and adherence. OBJECTIVE: To evaluate the efficacy and safety of saquinavir-soft-gelatin capsule (SGC)/ritonavir combination (1600 mg/100 mg) vs efavirenz (600 mg) both once daily and combined with 2 nucleoside analogs twice daily. SETTING: Twenty-six centers in the United States, Canada, and Puerto Rico. PATIENTS: A total of 171 antiretroviral naive HIV-infected individuals were enrolled in a 48-week, phase 3, open-label, randomized study. MAIN OUTCOME MEASURE: Proportion of patients with HIV-RNA levels < 50 copies/mL. The pharmacokinetic profile of saquinavir-SGC was analyzed in a subset of randomly selected patients. RESULTS: In the primary intent-to-treat population at week 48, 51% (38/75) and 71% (55/77) of patients in the saquinavir-SGC/ritonavir and efavirenz groups, respectively, achieved HIV-RNA suppression < 50 copies/mL (P = .5392, 95% 1-sided confidence interval [CI] = -33.5%). In the on-treatment (OT) population, 73% (38/52) and 93% (54/58) of patients in the saquinavir-SGC/ritonavir and efavirenz groups, respectively, had effective viral suppression < 50 copies/mL (P = .5015, 95% 1-sided CI = -33.4%). Mean CD4+ cell counts increased by 239 and 204 cells/microliters (mcL), in the saquinavir-SGC/ritonavir and efavirenz groups, respectively, in the OT analysis (P = .058). Both regimens were reasonably well tolerated, although more gastrointestinal adverse events were reported with saquinavir-SGC/ritonavir. Pharmacokinetic profiles in 6 patients showed an observed median Cmin at 24 hours of 429 ng/mL (range, 68-1750 ng/mL). CONCLUSIONS: Once-daily efavirenz was statistically superior to once-daily saquinavir-SGC/ritonavir. Gastrointestinal adverse effects were commonly associated with treatment failure in the saquinavir-SGC/ritonavir arm of the study.

Adult↗
PubMed2006

Impact of a medically supervised safer injecting facility on drug dealing and other drug-related crime.

North America's first medically supervised safer injecting facility (SIF) recently opened in Vancouver, Canada. One of the concerns prior to the SIF's opening was that the facility might lead to a migration of drug activity and an increase in drug-related crime. Therefore, we examined crime rates in the neighborhood where the SIF is located in the year before versus the year after the SIF opened. No increases were seen with respect to drug trafficking (124 vs. 116) or assaults/robbery (174 vs. 180), although a decline in vehicle break-ins/vehicle theft was observed (302 vs. 227). The SIF was not associated with increased drug trafficking or crimes commonly linked to drug use.

British Columbia↗