Predictors of adherence and virologic outcome in HIV-infected patients treated with abacavir- or indinavir-based triple combination HAART also containing lamivudine/zidovudine

Predictors associated with HIV/AIDS patients dropout from antiretroviral therapy at Mettu Karl Hospital, southwest Ethiopia

Objective

The aim of this study was to determine the major risk factors of antiretroviral therapy dropout. The retrospective cohort research design was applied. 1512 HIV patients were included from Mettu Karl Hospital in Illubabor Zone, southwest part of Ethiopia from September 2005 to January 2018. Kaplan–Meier comparison and log-logistic regression accelerated failure time model were used.

Results

From the log-logistic regression result, the risk of dropout for patients with primary education status was 10.58% greater as compared to illiterate (p < 0.0110). The probability of dropout for patients with marital status separated was about 16.82% higher than those patients with marital status divorced (p < 0.0070). Being merchant, farmer and daily labour had a greater risk of dropout as compared to a housewife. Most of the HIV/AIDS patients on ART were dropout in a short period due to patients separated marital status, primary education, CD4, being merchants, farmer and daily labour. Investigation on the cause of antiretroviral therapy dropout from a number of AIDS clinics in the country is highly appreciated.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4267-3) contains supplementary material, which is available to authorized users.

Reporting quality of randomized controlled trials in patients with HIV on antiretroviral therapy: a systematic review

BACKGROUND

To allow for correct evaluation of clinical trial results, readers require comprehensive, clear, and highly transparent information on the methodology used and the results obtained. This study aimed to evaluate the quality of reporting in articles on randomized controlled trials (RCTs) of antiretroviral therapy (ART) in the field of HIV/AIDS.

METHODS

We searched for original articles on RCTs of ART developed in the field of HIV/AIDS in PubMed database by 5 April 2016. Searched articles were divided into three groups based on the revision year in which the Consolidated Standards of Reporting Trials (CONSORT) guidelines were published: Period 1 (1996-2001); Period 2 (2002-2010); and Period 3 (2011-2016). We evaluated the articles using the reporting rates of the 37 items in the CONSORT 2010 checklist, five items in the protocol deviation, and the three items in the ethics.

RESULTS

Fifty-two articles were extracted and included in this study. Many of the reporting rates calculated using the CONSORT 2010 checklist showed a significantly increasing trend over the successive periods (65% in Period 1, 67% in Period 2, 79% in Period 3; p < 0.0001). The items with reporting rates < 50% were "the presence or absence of a protocol change and the reason for such a change," "randomization and blinding," and "where the full trial protocol can be accessed." Reporting rates of deviations were as low as < 30%, while the reporting rates for patient compliance were the highest (>80% in Period 3) among the five items. The reporting rates for obtaining informed consent and approval by the ethics committee or institutional review board were high (>88%), regardless of the time period assessed.

CONCLUSION

In terms of representative RCT articles in the field of HIV/AIDS, the reporting rate of the items defined by CONSORT was approximately 70%, improving over the successive CONSORT statement revision periods.

Adherence to Antiretroviral Therapy and Virologic Failure: A Meta-Analysis

The often cited need to achieve ≥95% (nearly perfect) adherence to antiretroviral therapy (ART) for successful virologic outcomes in HIV may present a barrier to initiation of therapy in the early stages of HIV. This meta-analysis synthesized 43 studies (27,905 participants) performed across >26 countries, to determine the relationship between cut-off point for optimal adherence to ART and virologic outcomes. Meta-analysis was performed using a random-effect model to calculate pooled odds ratios with corresponding 95% confidence intervals. The mean rate of patients reporting optimal adherence was 63.4%. Compared with suboptimal adherence, optimal adherence was associated with a lower risk of virologic failure (0.34; 95% CI: 0.26-0.44). There were no significant differences in the pooled odds ratios among different optimal adherence thresholds (≥98-100%, ≥95%, ≥80-90%). Study design (randomized controlled trial vs observational study) (regression coefficient 0.74, 95% CI: 0.04-1.43, P < 0.05) and study region (developing vs developed countries; regression coefficient 0.56, 95% CI: 0.01-1.12, P < 0.05) remained as independent predictors of between-study heterogeneity, with more patients with optimal adherence from developing countries or randomized controlled trials experiencing virologic failure. The threshold for optimal adherence to achieve better virologic outcomes appears to be wider than the commonly used cut-off point (≥95% adherence). The cut-off point for optimal adherence could be redefined to a slightly lower level to encourage the prescribing ART at an early stage of HIV infection.

Predictors and correlates of adherence to combination antiretroviral therapy (ART) for chronic HIV infection: a meta-analysis

BACKGROUND

Adherence to combination antiretroviral therapy (ART) is a key predictor of the success of human immunodeficiency virus (HIV) treatment, and is potentially amenable to intervention. Insight into predictors or correlates of non-adherence to ART may help guide targets for the development of adherence-enhancing interventions. Our objective was to review evidence on predictors/correlates of adherence to ART, and to aggregate findings into quantitative estimates of their impact on adherence.

METHODS

We searched PubMed for original English-language papers, published between 1996 and June 2014, and the reference lists of all relevant articles found. Studies reporting on predictors/correlates of adherence of adults prescribed ART for chronic HIV infection were included without restriction to adherence assessment method, study design or geographical location. Two researchers independently extracted the data from the same papers. Random effects models with inverse variance weights were used to aggregate findings into pooled effects estimates with 95% confidence intervals. The standardized mean difference (SMD) was used as the common effect size. The impact of study design features (adherence assessment method, study design, and the United Nations Human Development Index (HDI) of the country in which the study was set) was investigated using categorical mixed effects meta-regression.

RESULTS

In total, 207 studies were included. The following predictors/correlates were most strongly associated with adherence: adherence self-efficacy (SMD = 0.603, P = 0.001), current substance use (SMD = -0.395, P = 0.001), concerns about ART (SMD = -0.388, P = 0.001), beliefs about the necessity/utility of ART (SMD = 0.357, P = 0.001), trust/satisfaction with the HIV care provider (SMD = 0.377, P = 0.001), depressive symptoms (SMD = -0.305, P = 0.001), stigma about HIV (SMD = -0.282, P = 0.001), and social support (SMD = 0.237, P = 0.001). Smaller but significant associations were observed for the following being prescribed a protease inhibitor-containing regimen (SMD = -0.196, P = 0.001), daily dosing frequency (SMD = -0.193, P = 0.001), financial constraints (SMD -0.187, P = 0.001) and pill burden (SMD = -0.124, P = 0.001). Higher trust/satisfaction with the HIV care provider, a lower daily dosing frequency, and fewer depressive symptoms were more strongly related with higher adherence in low and medium HDI countries than in high HDI countries.

CONCLUSIONS

These findings suggest that adherence-enhancing interventions should particularly target psychological factors such as self-efficacy and concerns/beliefs about the efficacy and safety of ART. Moreover, these findings suggest that simplification of regimens might have smaller but significant effects.

Predictors and correlates of adherence to combination antiretroviral therapy (ART) for chronic HIV infection: a meta-analysis

Background

Adherence to combination antiretroviral therapy (ART) is a key predictor of the success of human immunodeficiency virus (HIV) treatment, and is potentially amenable to intervention. Insight into predictors or correlates of non-adherence to ART may help guide targets for the development of adherence-enhancing interventions. Our objective was to review evidence on predictors/correlates of adherence to ART, and to aggregate findings into quantitative estimates of their impact on adherence.

Methods

We searched PubMed for original English-language papers, published between 1996 and June 2014, and the reference lists of all relevant articles found. Studies reporting on predictors/correlates of adherence of adults prescribed ART for chronic HIV infection were included without restriction to adherence assessment method, study design or geographical location. Two researchers independently extracted the data from the same papers. Random effects models with inverse variance weights were used to aggregate findings into pooled effects estimates with 95% confidence intervals. The standardized mean difference (SMD) was used as the common effect size. The impact of study design features (adherence assessment method, study design, and the United Nations Human Development Index (HDI) of the country in which the study was set) was investigated using categorical mixed effects meta-regression.

Results

In total, 207 studies were included. The following predictors/correlates were most strongly associated with adherence: adherence self-efficacy (SMD = 0.603, P = 0.001), current substance use (SMD = -0.395, P = 0.001), concerns about ART (SMD = -0.388, P = 0.001), beliefs about the necessity/utility of ART (SMD = 0.357, P = 0.001), trust/satisfaction with the HIV care provider (SMD = 0.377, P = 0.001), depressive symptoms (SMD = -0.305, P = 0.001), stigma about HIV (SMD = -0.282, P = 0.001), and social support (SMD = 0.237, P = 0.001). Smaller but significant associations were observed for the following being prescribed a protease inhibitor-containing regimen (SMD = -0.196, P = 0.001), daily dosing frequency (SMD = -0.193, P = 0.001), financial constraints (SMD -0.187, P = 0.001) and pill burden (SMD = -0.124, P = 0.001). Higher trust/satisfaction with the HIV care provider, a lower daily dosing frequency, and fewer depressive symptoms were more strongly related with higher adherence in low and medium HDI countries than in high HDI countries.

Conclusions

These findings suggest that adherence-enhancing interventions should particularly target psychological factors such as self-efficacy and concerns/beliefs about the efficacy and safety of ART. Moreover, these findings suggest that simplification of regimens might have smaller but significant effects.

Electronic supplementary material

The online version of this article (doi:10.1186/s12916-014-0142-1) contains supplementary material, which is available to authorized users.

Co-formulated abacavir-lamivudine-zidovudine for initial treatment of HIV infection and AIDS

BACKGROUND

UNAIDS estimates that 34 million people are currently living with the human immunodeficiency virus (HIV) worldwide. Currently recommended regimens for initiating HIV treatment consist of either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or ritonavir-boosted protease inhibitor (PI) combined with two nucleoside reverse transcriptase inhibitors (NRTIs). However, there may be some patients for whom NNRTIs and PIs may not be appropriate. This is an update of the review published in the Cochrane Library Issue 3, 2009.

OBJECTIVES

To evaluate the effects of any fixed-dose combination of three NRTIs (co-formulated abacavir-lamivudine-zidovudine) for initial treatment of HIV infection.

SEARCH METHODS

Between December 2010 and July 2011, we used standard Cochrane methods to search electronic databases and conference proceedings with relevant search terms without limits to language or publication status.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) with a minimum follow-up time of six months which compared co-formulated abacavir-lamivudine-zidovudine with either PI-based or NNRTI-based therapy among antiretroviral-naive HIV-infected patients aged at least 13 years.

DATA COLLECTION AND ANALYSIS

Three authors independently selected eligible studies, assessed risk of bias, and extracted data; resolving discrepancies by consensus. We calculated the risk ratio (RR) or mean difference (MD), as appropriate, with its 95% confidence interval (CI) and conducted meta-analysis using the random-effects method because of significant statistical heterogeneity (P<0.1).

MAIN RESULTS

We identified 15 potentially eligible RCTs, four of which met our inclusion criteria. The four included RCTs were conducted in the United States of America (USA); USA, Puerto Rico, Guatemala, Dominican Republic, and Panama; USA and Mexico; and Botswana, respectively. The RCTs compared co-formulated abacavir-lamivudine-zidovudine to treatment based on efavirenz (NNRTI), nelfinavir (PI), atazanavir (PI), and co-formulated lopinavir-ritonavir (PI), respectively. Overall, there was no significant difference in virological suppression between co-formulated abacavir-lamivudine-zidovudine and NNRTI- or PI-based therapy (4 trials; 2247 participants: RR 0.73, 95% CI 0.39 to 1.36). However, the results showed significant heterogeneity (I(2)=79%); with co-formulated abacavir-lamivudine-zidovudine inferior to NNRTI (1 trial, 1147 participants: RR 0.35, 95%CI 0.26 to 0.49) but with a trend towards co-formulated abacavir-lamivudine-zidovudine being superior to PI (3 trials, 1110 participants: RR 1.07, 95%CI 1.00 to 1.16; I(2)=0%). We found no significant differences between co-formulated abacavir-lamivudine-zidovudine and either PI or NNRTI on CD4+ cell counts (3 trials, 1687 participants: MD -0.01, 95%CI -0.11 to 0.09; I(2)=0%), severe adverse events (4 trials: RR 1.22, 95%CI 0.78 to 1.92; I(2)=62%) and hypersensitivity reactions (4 trials: RR 4.04, 95% CI 0.41 to 40.02; I(2)=72%). Only two studies involving PIs reported data on the lipid profile. One study found that the mean increase in total cholesterol from baseline to 96 weeks was significantly lower with co-formulated abacavir-lamivudine-zidovudine than with nelfinavir, but there were no differences with triglyceride levels. The second study found the fasting lipid profile to be comparable in both co-formulated abacavir-lamivudine-zidovudine and atazanavir arms at 48 weeks.The significant heterogeneity of effects for most outcomes evaluated was largely due to differences in the control therapy used in the included trials (i.e. NNRTIs or PIs). Using the GRADE approach, we rated the overall quality of the evidence on the relative effects of co-formulated abacavir-lamivudine-zidovudine for initial treatment of HIV infection as moderate. The main reason for downgrading the quality of the evidence was imprecision of the findings. The estimate of the treatment effect for each outcome has wide confidence intervals, which extend from the fixed-dose NRTI combination regimen being appreciably better to the regimen being appreciably worse than PI- or NNRTI-based regimens.

AUTHORS' CONCLUSIONS

This review provides evidence that co-formulated abacavir-lamivudine-zidovudine remains a viable option for initiating antiretroviral therapy, especially in HIV-infected patients with pre-existing hyperlipidaemia. The varied geographical locations of the included trials augment the external validity of these findings. We are moderately confident in our estimate of the treatment effects of the triple NRTI regimen as initial therapy for HIV infection. In the context of the GRADE approach, such moderate quality of evidence implies that the true effects of the regimen are likely to be close to the estimate of effects found in this review; but there is a possibility that they could be substantially different.  Further research should be geared towards defining the subgroup of HIV patients for whom this regimen will be most beneficial.

Efficacy and Safety of Abacavir/Lamivudine/Zidovudine Plus Tenofovir in HBV/HIV-1 Coinfected Adults: 48-Week Data

In HBV/HIV-coinfected patients, the risk of end-stage liver disease and death is increased. This open-label, prospective, pilot study evaluated abacavir/lamivudine/zidovudine twice daily plus tenofovir once daily in HBV/HIV-coinfected antiretroviral-naïve subjects. Nine adults (8 males) enrolled, with baseline mean HIV-1 RNA = 4.5 log₁₀ copies/mL, HBV DNA = 9.0 log₁₀ copies/mL, and median CD4 count =158 cells/mm³. No subject had baseline ALT >5x ULN.

Six subjects completed the study: 1 withdrew due to non-treatment-related toxoplasmosis and 2 were lost-to-follow-up. At week 48, 100% (6/6) of remaining subjects had ≥2 log₁₀ decrease in HBV DNA, and 100% (6/6) and 83% (5/6) had HIV-1 RNA <400 and <50 copies/mL, respectively. Median change from baseline in CD4 count was 157 cells/mm³. One subject experienced treatment-related grade 3 leukopenia. These results demonstrate that abacavir/lamivudine/zidovudine and tenofovir were well tolerated with sustained HIV-1 and HBV antiviral activity through 48 weeks in HBV/HIV-coinfected, antiretroviral-naïve subjects.

Quality of life in HIV-infected individuals receiving antiretroviral therapy is related to adherence

This study assesses changes in quality of life (QoL) over time among HIV-infected individuals receiving antiretroviral therapy (ART) and evaluates how this relates to ARTadherence. Prospective, longitudinal data were examined from 1050 participants in two large, randomized, multi-centre antiretroviral clinical trials. QoL was assessed by the SF-12; adherence by the Terry Beirn Community Programs for Clinical Research on AIDS Antiretroviral Medication Self-report. Participants included 20% women, 53% African Americans, 16% Latinos; mean age was 39 years; mean baseline CD4+ cell count 230 cells/mm3; 89% were ART-naïve at entry. Baseline physical and mental health summary QoL scores were 45.4 and 42.9, comparable to scores reported in other advanced HIV populations. Significant improvements in mean QoL scores were seen for the group as a whole after 1 to 4 months on new ART regimens, and persisted for 12 months. Participants reporting 100% ART adherence achieved significantly higher QoL scores at 12 months compared to those with poorer adherence, particularly if 100% adherence was consistent (p < 0.001). Those with at least 80% ART adherence had smaller gains in QoL at 12 months when compared to baseline, while those with < 80% adherence had worsening of QoL. In this analysis, ART adherence was associated with improved QoL, particularly if adherence was sustained.

Abacavir/lamivudine/zidovudine maintenance after standard induction in antiretroviral therapy-naïve patients: FREE randomized trial interim results

Maintenance with a triple nucleoside reverse transcriptase Inhibitor (NRTI) regimen after successful induction with a dual NRTI/protease inhibitor (PI) combination may be advantageous, because of low pill burden, favorable lipids, and less drug interactions. This strategy to become free of PI-related problems without losing viral efficacy has not been formally tested. We performed a randomized, open-label, multicenter, 96-week comparative study in antiretroviral therapy (ART)-naïve patients with CD4 <or=350 cells/mm(3) and HIV-1 RNA concentrations (viral load [VL]) greater than 30,000 copies per milliliter. Patients were randomized after reaching VL less than 50 copies per milliliter on two consecutive occasions between 12 and 24 weeks after start of zidovudine/lamuvidine and lopinavir/ritonavir combination. Eligible subjects switched to abacavir/lamivudine/zidovudine (TZV) or continued the PI-containing regimen. Here we present the 48-week data with virologic success rate (failure: VL > 50 copies per milliliter). Two hundred seven patients had similar baseline (BL) characteristics: median CD4 180 cells/mm(3), median VL 5.19 log(10) copies per milliliter. One hundred twenty subjects (58%) met randomization criteria. Baseline VL differed significantly between dropouts and randomized subjects (median 5.41 versus 5.06 log(10) copies per milliliter, p = 0.017), as did CD4 cells (median 160 and 200 cells/mm(3), p = 0.044). Sixty-one subjects received TZV and 59 subjects continued NRTIs/PI. At week 48, 2 patients in the TZV group and 5 in the PI group did not have a sustained virologic suppression (log rank test; p = 0.379). CD4 counts increased significantly in both arms. In ART-naïve patients, TZV maintenance had similar antiviral efficacy compared to continued standard ART at 48 weeks after baseline. Patients on successful standard ART can be safely switched to a NRTI-only regimen, at least for the tested time period.

A combination drug of abacavir-lamivudine-zidovudine (Trizivir) for treating HIV infection and AIDS

BACKGROUND

The human immunodeficiency virus (HIV) has become one of the greatest challenges to global public health. In 2007 UNAIDS estimated that 33.2 million people were living with HIV. Currently recommended regimens for initiating HIV treatment consist of either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or ritonvair-boosted protease inhibitor (PI) combined with two nucleoside reverse transcriptase inhibitors (NRTIs); however, there may be some patients for whom NNRTIs and PIs may not be appropriate.

OBJECTIVES

The aim of this review was to evaluate the effects of Trizivir, a fixed-dose combination of three NRTIs (abacavir-lamivudine-zidovudine) for initial treatment of HIV infection.

SEARCH STRATEGY

In February 2008, we searched the Cochrane Library, PubMed, EMBASE, AIDSearch and GATEWAY and checked reference lists of identified articles. In May 2009, we repeated the search in PubMed and the Cochrane Library.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) with a minimum follow-up time of six months which compared Trizivir with either a PI- or NNRTI-based therapy among antiretroviral-naive HIV-infected patients aged at least 13 years.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data. We calculated the relative risk (RR) or mean difference (as appropriate) for each outcome with its 95% confidence interval (CI) and conducted meta-analysis using the random-effects method because of significant statistical heterogeneity (P<0.1).

MAIN RESULTS

We identified nine potentially eligible RCTs, three of which met our inclusion criteria. One trial compared Trizivir to efavirenz (an NNRTI) plus two or three NRTIs; the second trial compared Trizivir to a treatment based on the PI nelfinavir; and the third compared Trizivir to atazanavir (a PI) plus two NRTIs. Overall, there was no significant difference in the incidence of virological failure between participants on Trizivir and those on PI-based or NNRTI-based therapy (three trials, N=1687; RR 1.14, 95% CI 0.56 to 2.32). However, there was significant heterogeneity between the results of the three trials (heterogeneity P=0.009, I(2)=79%), with a significant increase in virological failure for Trizivir compared to efavirenz (N=1147; RR 1.93, 95% CI 1.46 to 2.55) but no difference between Trizivir and PIs (two trials, N=540; RR 0.82, 95% CI 0.50 to 1.36). We found no significant differences between Trizivir and either the PI or NNRTI on CD4+ cell counts (standardized mean difference -0.01, 95% CI -0.11 to 0.09, heterogeneity P=0.59, I(2)=0%), severe adverse events (RR 1.41, 95% CI 0.61 to 3.25, heterogeneity P=0.03, I(2)=73%) and hypersensitivity reactions (RR 4.04, 95% CI 0.41 to 40.02, heterogeneity P=0.03, I(2)=72%). Only the studies involving PIs reported the effect of the treatment regimens on the lipid profile. One study found that at 96 weeks, the mean increase in total cholesterol from baseline was significantly lower with Trizivir than with nelfinavir, but there were no significant differences with triglyceride levels. The second study found the fasting lipid profile to be comparable in both the Trizivir and atazanavir arms at 48 weeks.

AUTHORS' CONCLUSIONS

Our findings indicate that Trizivir remains a viable option for initiating antiretroviral therapy, especially in HIV-infected patients with pre-existing hyperlipidaemia and those who do not tolerate ritonavir.

Patterns and predictors of changes in adherence to highly active antiretroviral therapy: longitudinal study of men and women

BACKGROUND

Adherence to therapy is a dynamic behavior. However, few studies have identified factors associated with changes in adherence to highly active antiretroviral therapy (HAART) among men and women.

METHODS

From 1999 through 2004, self-reported adherence to HAART was recorded twice yearly as part of 2 prospective cohort studies. At each study visit, participants were categorized as being 100% adherent if they reported full adherence with their HAART regimen over the past 4 days (for men) and 3 days (for women). Repeated-measures logistic regression models were used to identify predictors for changes in adherence between consecutive visits.

RESULTS

Of the participants, 640 men and 1304 women contributed 2803 and 5972 visit-pairs, respectively. Among white men, the prevalence of 100% adherence decreased from 91% in 1998 to 80% in 2003. Among women and African American men, the prevalence of full adherence was lower (75% and 77% on average, respectively) and stable over time (P>.6). In both cohorts, the presence of clinical symptoms was independently associated with decreasing adherence (odds ratio [OR], 1.38 in men and 1.48 in women). Depression in men (OR, 1.44) and use of alcohol in women (OR, 1.81, 1.52, and 1.29, for binge drinking, moderate-to-heavy drinking, and low consumption, respectively) also predicted decreasing adherence. In addition, the use of drugs by men and women (OR, 0.61 and 0.58, respectively) and alcohol binging by women (OR, 0.41) were negatively associated with improving adherence.

CONCLUSIONS

Adherence to antiretroviral treatment is a dynamic process; modifiable risk factors are associated with increasing and decreasing adherence, suggesting specific interventions. Moreover, the association of these risk factors with changes in adherence may differ by sex.

Patient preferences among third agent HIV medications: a US and German perspective

The objective is to assess patient preferences for attributes associated with third agent HIV medications, including fosamprenavir/ritonavir (FPVr), fosamprenavir (FPV), lopinavir/ritonavir (LPVr), atazanavir (ATZ), and efavirenz (EFV). Subjects with HIV were recruited in the US and Germany to complete a computerized adaptive conjoint survey that assessed 13 attributes, including moderate to severe side effects, regimen convenience, drug resistance and efficacy. Literature on the target third-agent HIV drugs was used to identify percentage risk and severity level descriptions for each attribute. The derived preference (utility) weights for each attribute level informed the calculation of relative importance estimates for each attribute and the desirability of combinations of attributes matching the respective target third agents. The analysis included 288 HIV-positive participants (US: 132; Germany: 156), 205 of whom were treatment-experienced and 83 of whom were treatment-naïve. Of the 13 medication attributes evaluated, developing drug resistance, the risk of lipodystrophy, the risk of gastronitestinal side effects (diarrhoea, nausea and vomiting) and regimen convenience had the greatest impact on preferences. The profile based on FPVr was most preferred. Differences in the risk of developing drug resistance, risk of lipodystrophy, risk of gastrointestinal side effects and regimen convenience would likely be most influential in the perceived relative value of a third-agent medication. Physicians may wish to consider these features, especially when discussing HIV treatment options with their patients.

The pharmacology of HIV drug resistance

Drug resistance to human immunodeficiency virus (HIV) is a major factor in the failure of antiretroviral therapy.1 In order for practitioners to provide effective pharmaceutical care to their HIV patients, it is essential that they understand the mechanisms of HIV drug resistance as well as the various factors that can contribute to its emergence. This article is based on didactic content from the infectious disease section of the Integrated Sequence II Course in the PharmD program at South University. In the course, students are first given an overview that includes key structural components of HIV and a discussion of the HIV life cycle. A detailed presentation on the pharmacology of the various classes of antiretroviral agents follows. The clinical impact and prevalence of HIV drug resistance is then discussed along with factors that might contribute to it. Mechanisms of drug resistance for each class of antiretroviral agents are presented in detail followed by a discussion of the basis and clinical utility of HIV drug resistance testing. Finally, new targets for HIV pharmacotherapy are presented along with an overview of new antiretroviral agents that are being developed. Content taught in lecture is reinforced by relevant case studies that students work on in small groups during the recitation period.

Análisis de las causas de suspensión del régimen antirretroviral simplificado abacavir, lamivudina y zidovudina

OBJECTIVE

To identify and analyze the most common causes for the discontinuation of antiretroviral therapy, including the co-formulation of abacavir, lamivudine and zidovudine (ABC-3TC-AZT).

METHOD

An observational, retrospective study was carried out on patients receiving antiretroviral therapy with ABC-3TC-AZT seen in the Pharmacy Department s outpatient unit from February 2002 through June 2004. The causes for discontinuation among patients withdrawing from this therapy were analyzed. Adherence was assessed using computerized dispensation records. A Kaplan-Meier survival analysis was designed in order to identify factors predictive of discontinuation.

RESULTS

In all, 114 patients (85 males, 74.6%) received this therapy - 25.4% of them were naïve patients - and 34.2% (39/114) withdrew from this regimen, amongst them 44.8% (13/29) of naïve subjects. In 92.3% of cases this happened before treatment week 48. Discontinuation causes included: adverse reactions (46.1%), voluntary discontinuation (33.3%), clinical decision (15.4%), and other reasons (5.1%). A possible hypersensitivity reaction to ABC was reported for 9 patients. A greater likelihood of discontinuation was associated with detectable viral load at therapy onset, ex-parenteral drug abuser status, and naïve status (p < 0.05).

CONCLUSIONS

A high percentage of discontinuations due to adverse events and voluntary withdrawal was found, particularly early during treatment. Patients who may therapeutically benefit from this regimen, particularly naïve subjects, should be identified, and interventions to improve adherence and optimize recovery parameters should be implemented.