Data on adverse drug reactions (ADRs) related to antiretroviral (ARV) use in public health practice are few indicating the need for ART safety surveillance in clinical care.
To evaluate the incidence, type and risk factors associated with adverse drug reactions (ADRs) among patients on antiretroviral drugs (ARV).
Patients initiated on ARVs between May 2006 and May 2009 were evaluated in a retrospective cohort analysis in three health facilities in Nigeria. Regimens prescribed include nucleoside backbone of zidovudine (AZT)/lamivudine (3TC), stavudine (d4T)/3TC, or tenofovir (TDF)/3TC in combination with either nevirapine (NVP) or efavirenz (EFV). Generalized Estimating Equation (GEE) model was used to identify risk factors associated with occurrence of ADR.
2650 patients were followed-up for 2456 person-years and reported 114 ADRs (incidence rate = 4.6/100 person-years).There were more females 1706(64%) and 73(64%) of the ADRs were reported by women. Overall, 61(54%) of ADRs were reported by patients on AZT with 54(47%) of these occurring in patients on AZT/NVP. The commonest ADRs reported were pain 25(30%) and skinrash 10(18%). Most ADRs were grade 1(39%) with only 1% being life threatening (grade 4). Adjusted GEE analysis showed that ADR was less likely to occur in patients on longer duration of ART compared to the first six months on treatment; 6-12 months AOR 0.38(95% CI:0.16-0.91) and 12-24 months AOR 0.34(95% CI:0.16-0.73) respectively. Compared to patients on TDF, ADR was less likely to occur in patients on d4T and AZT AOR 0.18(95% CI 0.05-0.64) and AOR 0.24(95% CI:0.7-0.9) respectively. Age, gender and CD4 count were not significantly associated with ADRs.
ADRs are more likely to occur within the first six months on treatment. Close monitoring within this period is required to prevent occurrence of severe ADR and improve ART adherence. Further research on the tolerability of tenofovir in this environment is recommended.
Adverse drug reactions; ADR; Antiretroviral; Zidovudine; Stavudine; Tenofovir; HIV/AIDS; Nigeria; Incidence; Risk factors
Multidrug regimens and corresponding drug interactions cause many adverse reactions and treatment failures. Drug efflux transporters: P-gp, MRP, BCRP in conjunction with metabolizing enzymes (CYPs) are major factors in such interactions. Most effective combination antiretrovirals (ARV) therapy includes a PI or a NNRTI or two NRTI. Coadministration of such ARV may induce efflux transporters and/or CYP3A4 resulting in sub-therapeutic blood levels and therapeutic failure due to reduced absorption and/or increased metabolism. A similar prognosis is true for ARV-compounds and drugs of abuse combinations. Morphine and nicotine enhance CYP3A4 and MDR1 expression in vitro. A 2.5 fold rise of cortisol metabolite was evident in smokers relative to nonsmokers. Altered functions of efflux transporters and CYPs in response to ARV and drugs of abuse may result in altered drug absorption and metabolism. Appropriate in vitro models can be employed to predict such interactions. Influence of genetic polymorphism, SNP and inter-individual variation in drug response has been discussed. Complexity underlying the relationship between efflux transporters and CYP makes it difficult to predict the outcome of HAART as such, particularly when HIV patients taking drugs of abuse do not adhere to HAART regimens. HIV+ pregnant women on HAART medications, indulging in drugs of abuse, may develop higher viral load due to such interactions and lead to increase in mother to child transmission of HIV. A multidisciplinary approach with clear understanding of mechanism of interactions may allow proper selection of regimens so that desired therapeutic outcome of HAART can be reached without any side effects.
P-glycoprotein; Multidrug resistance-associated protein; Breast cancer resistance protein; Cytochrome P-450; Antiretrovirals agents; Protease inhibitors and drugs of abuse
The efficacy of an antiretroviral (ARV) treatment regimen depends on the activity of the regimen’s individual ARV drugs and the number of HIV-1 mutations required for the development of resistance to each ARV — the genetic barrier to resistance. ARV resistance impairs the response to therapy in patients with transmitted resistance, unsuccessful initial ARV therapy and multiple virological failures. Genotypic resistance testing is used to identify transmitted drug resistance, provide insight into the reasons for virological failure in treated patients, and help guide second-line and salvage therapies. In patients with transmitted drug resistance, the virological response to a regimen selected on the basis of standard genotypic testing approaches the responses observed in patients with wild-type viruses. However, because such patients are at a higher risk of harbouring minority drug-resistant variants, initial ARV therapy in this population should contain a boosted protease inhibitor (PI) — the drug class with the highest genetic barrier to resistance.
In patients receiving an initial ARV regimen with a high genetic barrier to resistance, the most common reasons for virological failure are nonadherence and, potentially, pharmacokinetic factors or minority transmitted drug-resistant variants. Among patients in whom first-line ARVs have failed, the patterns of drug-resistance mutations and cross-resistance are often predictable. However, the extent of drug resistance correlates with the duration of uncontrolled virological replication. Second-line therapy should include the continued use of a dual nucleoside/nucleotide reverse transcriptase inhibitor (NRTI)-containing backbone, together with a change in the non-NRTI component, most often to an ARV belonging to a new drug class.
The number of available fully active ARVs is often diminished with each successive treatment failure. Therefore, a salvage regimen is likely to be more complicated in that it may require multiple ARVs with partial residual activity and compromised genetic barriers of resistance to attain complete virological suppression. A thorough examination of the patient’s ARV history and prior resistance tests should be performed because genotypic and/or phenotypic susceptibility testing is often not sufficient to identify drug-resistant variants that emerged during past therapies and may still pose a threat to a new regimen. Phenotypic testing is also often helpful in this subset of patients. ARVs used for salvage therapy can be placed into the following hierarchy: (i) ARVs belonging to a previously unused drug class; (ii) ARVs belonging to a previously used drug class that maintain significant residual antiviral activity; (iii) NRTI combinations, as these often appear to retain in vivo virological activity, even in the presence of reduced in vitro NRTI susceptibility; and rarely (iv) ARVs associated with previous virological failure and drug resistance that appear to have possibly regained their activity as a result of viral reversion to wild type. Understanding the basic principles of HIV drug resistance is helpful in guiding individual clinical decisions and the development of ARV treatment guidelines.
Most of the current knowledge on antiretroviral (ARV) drug development and resistance is based on the study of subtype B of HIV-1, which only accounts for 10% of the worldwide HIV infections. Cumulative evidence has emerged that different HIV types, groups and subtypes harbor distinct biological properties, including the response and susceptibility to ARV. Recent laboratory and clinical data highlighting such disparities are summarized in this review. Variations in drug susceptibility, in the emergence and selection of specific drug resistance mutations, in viral replicative capacity and in the dynamics of resistance acquisition under ARV selective pressure are discussed. Clinical responses to ARV therapy and associated confounding factors are also analyzed in the context of infections by distinct HIV genetic variants.
HIV-1; drug resistance; genetic diversity; subtypes; clinical response
Because liver enzymes elevation (LEE) complicates antiretroviral (ARV) therapy, and because the strongest risk factor for ARV-related LEE is HBV/HCV coinfection, it is speculated that ARV-related LEE may be a form of immune reconstitution disease. This study summarizes the relation between immune reconstitution, ARV-induced LEE, and HBV/HCV coinfection.
Medical records of ARV-naïve HIV-infected patients initiating ARV were reviewed for hepatitis coinfection, LEE (grade ≥2 AST/ALT) and changes in CD4 T-cell counts over time in an urban HIV clinic. Risk factors for LEE were statistically evaluated, and changes in CD4 T-cell counts were estimated by a mixed-effects linear model.
Predictors of LEE included HBV/HCV coinfection (OR = 6.44) and stavudine use (OR = 2.33). Nelfinavir use was protective (OR = 0.45). The mean rate of change in CD4 T-cell counts was higher in HBV/HCV coinfected subjects who developed LEE (99 cells/μL per month) compared with non-coinfected subjects who did not develop LEE (59 cells/μL per month, P = 0.03), non-coinfected subjects who developed LEE (36 cells/μL per month, P = 0.01), and coinfected subjects who did not develop LEE, 38% higher (62 cells/μL per month; P = 0.11)
A more robust immune restoration was observed among HBV/HCV coinfected subjects who developed liver enzyme elevation after antiretroviral initiation compared with other groups. This finding suggests that ARV-related liver enzyme elevation may be related in part to immune reconstitution, as measured by changes in CD4 T-cell counts.
Hepatotoxicity; Liver enzymes elevation; Antiretroviral drugs; Immune reconstitution; HIV/AIDS
Antiretroviral (ARV) treatment interruptions are associated with virologic rebound, drug resistance, and increased morbidity and mortality. The Medicare Part D prescription drug benefit, implemented on January 1st, 2006, increased consumer cost-sharing. Consumer cost-sharing is associated with decreased access to medications and adverse clinical outcomes. We assessed the association of Part D implementation with treatment interruptions by studying 125 HIV-infected homeless and marginally housed individuals with drug coverage receiving ARV therapy. Thirty-five percent of respondents reported Medicare coverage and 11% reported ARV interruptions. The odds of ARV interruptions were six times higher among those with Part D coverage and remained significant after adjustment. The majority of Part D-covered respondents reporting ARV interruptions cited increased cost as their primary barrier. Directed interventions to monitor the long-term effects of increased cost burden on interruptions and clinical outcomes and to reduce cost burden are necessary to avoid preventable increases in morbidity and mortality.
HIV/AIDS; Medicare; Adherence; Treatment interruption; Cost-sharing; Cost-related medication nonadherence
Great progress has been made in achieving universal access to antiretroviral therapy (ART). However, for successful viral suppression, patients must adhere to rigid and complex treatment regimens. With three quarters of antiretroviral (ARV) users in Africa adhering successfully, African countries have achieved extraordinary levels of adherence given the levels of poverty in which many ARV users live. Nevertheless, one quarter of ARV users still struggle to adhere and run the risk of experiencing viral replication, clinical progression or even drug resistance. Much has been written about ART adherence, but little has been done to systematically categorise the spectrum of factors that influence ART. In this paper, we use a Zimbabwean case study to develop a framework for ART programme planners and implementers seeking to identify and tackle social obstacles to adherence. We draw on interviews and group discussions with 25 nurses and 53 adult ARV users, which we analysed through a three-tiered thematic approach, allowing us to categorise our findings into broader dimensions that can transcend our case study and be applied elsewhere. Our findings suggest that ART adherence is influenced by the material, symbolic, relational and institutional contexts in which ARV users live as well as the patient's motivation, participation and psychosocial responses to ART. This framework allows us to examine both the social context in which ART programmes are located and the psychosocial factors that influence patient behaviours. We offer this framework as a resource for ART programme planners and implementers seeking to improve ART compliance in resource-poor settings. Copyright © 2011 John Wiley & Sons, Ltd.
Antiretroviral therapy; treatment; adherence; social context; HIV and AIDS; Zimbabwe
Previous studies have reported that majority of antiretroviral (ARV) treatment-naïve patients use traditional medicine (TM). Given that TM use is ubiquitous in South Africa especially for chronic conditions, there is a potential for ARV non-adherence and serious drug interactions among patients with HIV/AIDs who use TM. The motivating factors for TM use in HIV/AIDS patients on ARV and prophylaxis treatment have not been well defined in South Africa. This study aimed to investigate the prevalence, facilitators, predictors, and types of TM used among persons living with HIV/AIDS on antiretroviral treatment. The study was a cross-sectional survey which involved 100 participants enrolled at ARV clinics in two South African provinces. Univariate and bivariate analyses were performed to assess the relationships between variables and potential predictors of TM. Sixteen percent of participants on ARV reported TM use. Seventy-nine percent used TM prior to a diagnosis of HIV. Participants were more likely to use TM if they were from a rural province, female, older, unmarried, employed, had limited education, or were HIV-positive for less than five years. TM users reported utilizing herbal or medicinal mixtures that were claimed to heal all conditions. This study provides insights into the treatment modalities selected by patients with HIV/AIDS in South Africa who are receiving ARV. This study revealed that less than 20% of participants co-used TM and ARV. However, close to 80% of participants utilize TM before contracting HIV, which is in keeping with approximate estimates by the WHO.
AIDS; HIV infection; traditional medicine; alternative medicine; ARV
To describe the safety and efficacy of highly active antiretroviral therapy (HAART) in pregnant women treated in an integrated antenatal antiretroviral programme (ANC ARV).
A retrospective analysis was performed on patients attending the ANC ARV from August 2004 through February 2007.
Data was collected on 689 treatment-naïve pregnant women initiated on HAART. The mean age was 29.2 years. The mean baseline CD4+ count was 154 cells/uL and mean baseline HIV viral load was 101,561 copies/ml. Tuberculosis was the most prevalent presenting opportunistic infection (7.7%). Stavudine, lamivudine, and nevirapine were initiated in 82% of women with the most frequent adverse drug reaction being nevirapine-associated skin rash (3.5%). Mean gestational age at HAART initiation was 27 weeks. Among women with follow-up data, 80% gained 50 or more CD4 cells/uL, and 80.5% achieved viral suppression to <1000 copies/ml. Of 302 mother/infant pairs who completed postnatal follow-up, the HIV transmission rate was 5%. In women who received more than seven weeks of HAART during pregnancy, transmission was 0.3%.
Within the ANC ARV programme, initiating pregnant women on HAART was feasible, safe, and effective. Advanced gestational age at treatment initiation and loss to follow-up emerge as important challenges in this population.
HIV/AIDS; pregnancy; high active antiretroviral therapy (HAART); prevention of mother-to-child transmission (PMTCT)
Purpose of Review
Highly active antiretroviral therapy (HAART) use has markedly reduced AIDS-related mortality and opportunistic illness. With improved survival, cardiovascular disease (CVD) has emerged as an important non-infectious chronic co-morbidity among antiretroviral (ARV)-treated HIV-infected persons.
HIV infection can impact CVD and co-morbidiities known to increase CVD risk. Untreated HIV can cause proatherogenic elevations in serum lipids. Chronic HIV viremia results in increases in systemic inflammation, hypercoagulation, and reductions in endovascular reactivity, all of which are at least partially reversible with virally suppressive HAART. Chronic T cell activation can also result in adverse vascular effects. Use of some ARV drugs can impact CVD risk by causing pro-atherogenic serum lipid elevations, induction of insulin resistance, increases in visceral adiposity or subcutaneous fat loss. Abacavir use may increase myocardial infarction risk by reducing vascular reactivity and/or increasing platelet activation. Traditional risk factors such as advancing age, smoking, hyperlipidemia, and hypertension remain important predictors of CVD among HAART-treated HIV-infected persons.
HIV in the HAART era is a chronic manageable condition. CVD is an important cause of morbidity among HIV-infected persons. Untreated HIV can increase CVD risk in several ways and these effects are at least partially reversible with successful treatment. Use of specific ARV’s can adversely impact CVD risk but the multiple long-term benefits of chronic HIV suppression and immune reconstitution achievable with potent HAART outweigh the adverse impact upon CVD risks that they may have. Standard CVD screening and risk-reducing interventions should be routinely undertaken for HIV-infected persons.
Cardiovascular disease in HIV infection; Inflammation; hypercoagulation; vascular functioning; Effects of antiretroviral drugs; Hyperlipidemia
Both Human Immunodeficiency Virus (HIV) infection and AIDS remain major public health crises in Nigeria, a country which harbors more people living with HIV/AIDS than any country in the world, with the exception of South Africa and India. In response to the HIV pandemic, global and international health initiatives have targeted several countries, including Nigeria, for the expansion of antiretroviral therapy (ART) programs for the increasing number of affected patients. The success of these expanded ART initiatives depends on the treated individual’s continual adherence to antiretroviral (ARV) drugs. Thirteen peer-reviewed studies concerning adherence to ART in Nigeria were reviewed with very few pediatric and adolescent studies being found. Methodologies of adherence measurement were analyzed and reasons for nonadherence were identified in the geopolitical zones in the federal republic of Nigeria. The results of the literature review indicate that adherence to ART is mixed (both high and low adherence) with patient self-recall identified as the common method of assessment. The most common reasons identified for patient nonadherence include the cost of therapy (even when the drugs are heavily subsidized), medication side effects, nonavailability of ARV drugs, and the stigma of taking the drugs. This manuscript highlights the policy and practice implications from these studies and provides recommendations for future ART program management.
adherence; antiretroviral therapy (ART); HIV; PLWHA; Nigeria
In an effort to evaluate factors associated with the development of antiretroviral (ARV) resistance, we assessed the prevalence of toxicity-related regimen changes and modeled its association to the subsequent development of ARV resistance in a cohort of treatment-naive individuals initiating ARV therapy (ART). A retrospective analysis of patients initiating ART was conducted at the UAB 1917 Clinic from 1 January 2000 to 30 September 2007. Cox proportional hazards models were fit to identify factors associated with the development of resistance to ≥1 ARV drug class. Among 462 eligible participants, 14% (n=64) developed ARV resistance. Individuals with ≥1 toxicity-related regimen change (HR=3.94, 95% CI=1.09–14.21), initiating ART containing ddI or d4T (4.12, 1.19–14.26), and from a minority race (2.91, 1.16–7.28) had increased risk of developing resistance. Achieving virologic suppression within 12 months of ART initiation (0.10, 0.05–0.20) and higher pretreatment CD4 count (0.85 per 50 cells/mm3, 0.75–0.96) were associated with decreased hazards of resistance. Changes in ART due to drug intolerance were associated with the subsequent development of ARV resistance. Understanding the role of ARV drug selection and other factors associated with the emergence of ARV resistance will help inform interventions to improve patient care and ensure long-term treatment success.
In the current two decades, dyslipidemia and increased blood glucose as metabolic abnormalities are the most common health threats with a high incidence among HIV/AIDS patients on antiretroviral (ARV) treatment. Scientific investigations and reports on lipid and glucose disorders among HIV infected communities are inadequate especially in those developing such as Malaysia. This cross-sectional survey was mainly aimed to evaluate the prevalence of metabolic abnormalities and associated risk factors among HIV infected population patients on ARV medication.
In a single reference health center in Malaysia, 2739 adult HIV positive patients on antiretroviral therapy (ART) were studied cross-sectionally using medical records. Besides demographic variables and associated health disorders, those factors which can change the lipid and glucose levels were collected. Logistic Regression was used to find the potential risk factors (p < 0.05).
Majority of the studied population were male (81.1%) and aged between 30–49 (68.6%). Mean CD4 count was 474.25 (cells/mm3) while undetectable RNA viral load was common among 83.3 (%) of subjects. Among 1,583 patients with the recent blood lipid and glucose tests, increased levels of triglyceride (TG) and total cholesterol (TC) were frequently prevalent in half of the population as 59 (%) and 54.2 (%) while 28.7 (%), 35.1 (%) and 38.2 (%) had declined level of high-density lipoprotein (HDL), raised low-density lipoprotein (LDL) and fasting plasma glucose (FPG) which were less common. Dyslipidemia was common in 82.3 (%) of the subjects. Notably, medication with protease inhibitor (PI) was a potential risk for elevated triglyceride (odds ratio (OR) = 2.309, 95% confidence interval (CI) = 1.605–3.324, P = 0.001), high TC (OR = 1.561, 95% CI = 1.123–2.169, P = 0.008) and low HDL (OR = 1.449, 95% CI = 1.037–2.024, P = 0.029). As lifestyle factor, alcohol consumption results as significant risk factor for raised TG (OR = 2.653, 95% CI = 1.353–5.202, P = 0.004). Also having hepatitis raised risk of high FPG level (OR = 1.630, 95% CI = 1.197-2.220, P = 0.002) in this sample population.
Dyslipidemia is highly common in Malaysian HIV subjects receiving ARV medication. Lifestyle modification, changing PI and switch to other ARV regimen can help in reduction of these abnormalities. Also suitable strategies and plans are necessary to prevent cardiovascular diseases in future.
Lipid disorders; Metabolic abnormalities; Fasting plasma glucose; ARV medication; Protease inhibitor; Cardiovascular disease; Dyslipidemia; HIV positive; Malaysia
To determine rate of and risk factors for birth defects in infants born to HIV-infected women receiving nucleoside and protease inhibitor antiretroviral (ARV) therapy.
Birth defects were evaluated among infants on the Pediatric AIDS Clinical Trials Group 316 trial that studied addition of peripartum nevirapine to established ARV regimen for prevention of mother-to-child transmission. Maternal therapy was categorized by trimester of earliest exposure. Birth defects were coded using conventions of the Antiretroviral Pregnancy Registry.
Birth defects were detected in 60/1414 (4.2%; 95% CI 3.3–5.4%) infants including 30/636 (4.7%; 95% CI 3.2–6.7%) with first trimester ARV exposure and 30/778 (3.9%; 95% CI 2.6–5.5%) with exposure only after the first trimester (P=0.51). Rates of classes of defects were similar between first trimester compared to later exposure groups except heart defects which occurred in 16 (2.5%; 95% CI 1.4–4.1%) with first trimester ARV exposure and in six (0.8%; 95% CI 0.3–1.7%) infants with later exposure (P=0.02). Exposure to ARV was not associated with specific types of heart defects. Two cases of cardiomyopathy were noted.
ARV use in early pregnancy was not associated with an increased risk of birth defects overall. The possible association of ARV exposure with heart defects requires further surveillance.
Antiretrovirals; birth defects; HIV
Over the past decade, significant advances have been made in the treatment of HIV-1 infection using both pharmacologic and nonpharmacologic strategies to prevent mother-to-child transmission (MTCT). Optimal prevention of the MTCT of HIV requires antiretroviral drugs (ARV) during pregnancy, during labor, and to the infant. ARVs reduce viral replication, lowering maternal plasma viral load and thus the likelihood of MTCT. Postexposure prophylaxis of ARV agents in newborns protect against infection following potential exposure to maternal HIV during birth. In general, the choice of an ARV for treatment of HIV-infected women during pregnancy is complicated by the need to consider the effectiveness of the therapy for the maternal disease as well as the teratogenic or teratotoxic potential of these drugs. Clinicians managing HIV in pregnancy need to discuss the potential risks and benefits of available therapy options so that mothers can make informed decisions in choosing the best treatment regimen for themselves and for their children.
HIV; pregnancy; acquired immunodeficiency syndrome; antiretroviral agents
The use of antiretroviral drugs (ARV) to prevent mother-to-child HIV transmission (PMTCT) promises to be effective. However, limited data on the adverse effects of ARV among pregnant women and pregnancy outcomes have been reported in clinical practice.
This study aimed to assess adverse effects and outcomes among pregnant HIV-infected women receiving antiretroviral drugs for either antiretroviral therapy (ART) or PMTCT.
This cohort study was at Chonburi Hospital, Thailand, in 2002-2006.
A total of 246 pregnant HIV-infected women with the median age (range) of 27 (16-41) years were included in this study. ART was initiated in 16.3% for treatment during ANC, 66.7% for PMTCT during ANC, and 17.1% for PMTCT in labor. Adverse effects, especially anemia, were significantly associated with continuing combined ART in pregnancy (p<0.001). 88.9% delivered normal-term neonates. The prevalence of pre-term delivery was 10.2%. Overall, 24 adverse events from 21 pregnant women (8.5%) were noted. A significantly higher prevalence of pre-term delivery was noted in the groups continuing combined ART, or initiating of PMTCT during labor rather than ANC (p=0.02). The incidence of low Apgar scores was 3.6%, and these were associated with initiation of PMTCT during labor (p=0.004).
Adverse ARV events were more numerous among the pregnant women who needed ART than PMTCT. ANC is beneficial and strongly recommended for all pregnant HIV-infected women for better pregnancy outcomes.
HIV; Adverse effects; antiretroviral drugs; pregnancy; PMTCT.
The efficacy of various antiretroviral (ARV) therapy regimens for human immunodeficiency virus type 2 (HIV-2) infection remains unclear. HIV-2 is intrinsically resistant to the nonnucleoside reverse-transcriptase inhibitors and to enfuvirtide and may also be less susceptible than HIV-1 to some protease inhibitors (PIs). However, the mutations in HIV-2 that confer ARV resistance are not well characterized.
Twenty-three patients were studied as part of an ongoing prospective longitudinal cohort study of ARV therapy for HIV-2 infection in Senegal. Patients were treated with nucleoside reverse-transcriptase inhibitor (NRTI)– and PI (indinavir)–based regimens. HIV-2 pol genes from these patients were genotyped, and the mutations predictive of resistance in HIV-2 were assessed. Correlates of ARV resistance were analyzed.
Multiclass drug–resistance mutations (NRTI and PI) were detected in strains in 30% of patients; 52% had evidence of resistance to at least 1 ARV class. The reverse-transcriptase mutations M184V and K65R, which confer high-level resistance to lamivudine and emtricitabine in HIV-2, were found in strains from 43% and 9% of patients, respectively. The Q151M mutation, which confers multinucleoside resistance in HIV-2, emerged in strains from 9% of patients. HIV-1–associated thymidine analogue mutations (M41L, D67N, K70R, L210W, and T215Y/F) were not observed, with the exception of K70R, which was present together with K65R and Q151M in a strain from 1 patient. Eight patients had HIV-2 with PI mutations associated with indinavir resistance, including K7R, I54M, V62A, I82F, L90M, L99F; 4 patients had strains with multiple PI resistance–associated mutations. The duration of ARV therapy was positively associated with the development of drug resistance (P = .02). Nine (82%) of 11 patients with HIV-2 with detectable ARV resistance had undetectable plasma HIV-2 RNA loads (<1.4 log10 copies/mL), compared with 3 (25%) of 12 patients with HIV-2 with detectable ARV resistance (P = .009). Patients with ARV-resistant virus had higher plasma HIV-2 RNA loads, compared with those with non–ARV-resistant virus (median, 1.7 log10 copies/mL [range, <1.4 to 2.6 log10 copies/mL] vs. <1.4 log10 copies/mL [range, <1.4 to 1.6 log10 copies/mL]; P = .003).
HIV-2–infected individuals treated with ARV therapy in Senegal commonly have HIV-2 mutations consistent with multiclass drug resistance. Additional clinical studies are required to improve the efficacy of primary and salvage treatment regimens for treating HIV-2 infection.
Uncertainty about the value of antiretroviral therapy (ARV) adherence interventions may be a barrier to implementation and evaluation. Our objective is to estimate the minimum effectiveness required for ARV adherence interventions to deliver acceptable value.
We used a validated HIV computer simulation to estimate the impact of ARV adherence interventions on incremental costs and life expectancy. Across a wide range of intervention costs ($1000–10,000, one time or per year), we estimated the smallest effect size compatible with acceptable value (incremental cost-effective ratio ≤$100,000 per life-year), Effect sizes were measured using relative risk (RR) and absolute risk reduction (ARR), and these metrics were applied to nonadherence and nonadherence risk factors. Costs were estimated from a societal perspective ($2003) discounted at 3%.
To give acceptable value, a one-time $1000 intervention must reduce ARV nonadherence by RR ≤ 0.82 (ARR ≥ 0.04) for moderately nonadherent patients (20% of ARV doses missed) and RR ≤ 0.90 (ARR ≥ 0.05) for severely nonadherent patients (50% of ARV doses missed). A one-time $5000 intervention has an unacceptable value regardless of effect size for moderately nonadherent patients, and must reduce ARV nonadherence by RR ≤ 0.31 (ARR ≥ 0.69) for severely nonadherent patients. Interventions aimed at behavioral risk factors (e.g.. unhealthy alcohol use) may confer acceptable value (e.g., if ≤$2000 and effect RR ≤ 0.71 [ARR ≥ 0.29]).
ARV adherence interventions with plausible effect sizes may offer favorable value it they cost <$5000 one time or per year. ARV adherence interventions with a favorable value should become more integral components of HIV care.
adherence; AIDS; cost-effectiveness analysis; health services
While street drugs appear unlikely to alter the metabolism of antiretroviral (ARV) medications, several ARVs may induce or inhibit metabolism of various street drugs. However, research on these interactions is limited. Case reports have documented life-threatening overdoses of ecstasy and gamma-hydroxybutyrate after starting ritonavir, an ARV that inhibits several metabolic enzymes. For opioid addiction, methadone or buprenorphine are the treatments of choice. Because a number of ARVs decrease or increase methadone levels, patients should be monitored for methadone withdrawal or toxicity when they start or stop ARVs. Most ARVs do not cause buprenorphine withdrawal or toxicity, even if they alter buprenorphine levels, with rare exceptions to date including atazanavir/ritonavir associated with significant increases in buprenorphine and adverse events related to sedation and mental status changes in some cases. There are newer medications yet to be studied with methadone or buprenorphine. Further, there are many frequently used medications in treatment of complications of HIV disease that have not been studied. There is need for continuing research to define these drug interactions and their clinical significance.
Drug interactions; Street drugs; Methadone; Buprenorphine; Anti-HIV agents
The emergence of resistance to antiretroviral drugs is a major obstacle to the successful treatment of human immunodeficiency virus type 1 (HIV-1)-infected patients. In this work, we correlate clinical and virological trends such as viral load (VL) and CD4 counts to genotypic and phenotypic antiretroviral (ARV) resistance profiles of HIV-1 isolates from the B and non-B subtypes found in vertically infected children failing ARV therapy. Plasma samples were collected from 52 vertically HIV-1-infected children failing different ARV therapies. Samples underwent HIV-1 pol sequencing and phenotyping and were clustered into subtypes by phylogenetic analysis. Clinical data from each patient were analyzed together with the resistance (genotypic and phenotypic) data obtained. Thirty-five samples were from subtype B, 10 samples were non-B (subtypes A, C, and F), and 7 were mosaic samples. There was no significant difference concerning treatment data between B and non-B clades. Prevalence of known drug resistance mutations revealed slightly significant differences among B and non-B subtypes: L10I, 21 and 64%, K20R, 13 and 43%, M36I, 34 and 100%, L63P, 76 and 36%, A71V/T, 24 and 0%, and V77I, 32 and 0%, respectively, in the protease (0.0001 ≤ P ≤ 0.0886), and D67N, 38 and 8%, K70R, 33 and 0%, R211K, 49 and 85%, and K219Q/E, 31 and 0%, respectively, in the reverse transcriptase (0.0256 ≤ P ≤ 0.0704). Significant differences were found only in secondary resistance mutations and did not reflect significant phenotypic variation between clade B and non-B.
Remarkable advances in the treatment of human immunodeficiency virus (HIV) disease have been blunted by widespread suboptimal adherence (ie, nonadherence), which has emerged as a major barrier to achieving the primary goal of antiretroviral (ARV) therapy: suppression of HIV viral load. Nonsuppressed HIV viral load is associated with drug resistance, increased morbidity and mortality, and a higher risk of person-to-person HIV transmission. For HIV-infected individuals who are failing HIV treatment due to nonadherence, becoming adherent is a life-saving behavior change. However, overcoming nonadherence is one of the most daunting challenges in the successful management of HIV disease. The purpose of this paper is to provide clinicians with a better understanding of nonadherence to ARV treatment and to review the various factors that have been associated with either adherence or nonadherence. Strategies are presented that may help the nonadherent individual become ready to take HIV medications as prescribed.
noncompliance; treatment failure; AIDS
A virologic marker, the number of HIV RNA copies or viral load, is currently used to evaluate antiretroviral (ARV) therapies in AIDS clinical trials. This marker can be used to assess the antiviral potency of therapies, but may be easily affected by clinical factors such as drug exposures and drug resistance as well as baseline characteristics during the long-term treatment evaluation process. HIV dynamic studies have significantly contributed to the understanding of HIV pathogenesis and ARV treatment strategies. Viral dynamic models can be formulated through differential equations, but there has been only limited development of statistical methodologies for estimating such models or assessing their agreement with observed data. This paper develops a mechanism-based nonlinear differential equation models for characterizing long-term viral dynamics with ARV therapy. In this model we not only incorporate clinical factors (drug exposures and susceptibility), but also baseline covariate (baseline viral load, CD4 count, weight or age) into a function of treatment efficacy. A Bayesian nonlinear mixed-effects modeling approach is investigated with application to an AIDS clinical trial study. The effects of confounding interaction of clinical factors with covariate-based models are compared using the Deviance Information Criteria (DIC), a Bayesian version of the classical deviance for model assessment, designed from complex hierarchical model settings. Relationships between baseline covariate combined with confounding clinical factors and drug efficacy are explored. In addition, we compared models incorporating each of four baseline covariates through DIC and some interesting findings are presented. Our results suggest that modeling HIV dynamics and virologic responses with consideration of time-varying clinical factors as well as baseline characteristics may play an important role in understanding HIV pathogenesis, designing new treatment strategies for long-term care of AIDS patients.
AIDS; Baseline characteristics; Bayesian nonlinear mixed-effects models; long-term HIV dynamics; longitudinal data; time-varying drug efficacy
Without virologic testing, HIV-infected African children starting antiretroviral (ARV)-therapy are at risk for undetected virological failure and the development of ARV-resistance. We sought to determine the prevalence of early virologic failure (EVF), to characterize the evolution of ARV-resistance mutations, and to predict the impact on second-line therapy.
The prevalence of EVF (HIV-RNA >400 copies/mL on sequential visits after 6 months of therapy) was identified among 120 HIV-infected Ugandan children starting ARV-therapy. ARV-mutations were identified by population sequencing of HIV-1 pol in sequential archived specimens. Composite discrete genotypic susceptibility scores (dGSS) were determined for second-line ARV-regimens.
EVF occurred in 16 (13%) children and persisted throughout a median (IQR) 938 (760-1066) days of follow-up. M184V and non-nucleoside-reverse-transcriptase-inhibitor-associated mutations emerged within 6 months of EVF; thymidine-analog-mutations arose after 12 months. Worse dGSS scores correlated with increasing duration of failure (Spearman R = −0.47, p=0.001). Only 1 child met World Health Organization CD4 criteria for ARV-failure at the time of EVF or during the follow-up period.
A significant portion of HIV-infected African children experience EVF that would be undetected using CD4/clinical monitoring and resulted in the accumulation of ARV-mutations that could compromise second line therapy options.
Resistance; Antiretroviral therapy; HIV; children; Africa
The 2010 UNAIDS report states that approximately 34 million people are living with human immunodeficiency virus type 1 (HIV-1), despite highly active antiretroviral therapy (HAART). Despite being effective, ARV therapy has many disadvantages including a cost trajectory unsustainable for economically challenged countries, serious side effects, and the development of drug-resistant strains. Several measures are under way to develop alternatives for ARV therapy, particularly for the control of early HIV-1 infection, but lack of efficient drug targets and assays hinders the search of potential ARV molecules. The dendritic cells present in the mucosal tissue, together with CD4+ T lymphocytes and macrophages, are among the first cells to encounter HIV-1. The dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) molecule plays a crucial role in binding HIV-1 through high affinity interaction with viral envelope glycoprotein gp120. DC-SIGN, a mannose-binding C-type lectin expressed on cells in the mucosal tissue of the rectum, uterus and cervix, facilitates early HIV-1 infection after sexual transmission. In this study we report a novel target-specific high-throughput screening (HTS) assay capable of quantifying the binding as well as the inhibition of DC-SIGN and gp120. The specificity of the assay was determined through competitive inhibition while optimization occurred for DMSO tolerance (0.5%), Z’ factor (0.51), signal-to-noise ratio (3.26), and coefficient of variation (5.1%). For assay validation previously recognized antagonists of DC-SIGN/gp120 binding were tested to detect inhibition demonstrating the suitability of the assay for future HTS screen of potential inhibitors that block the binding between DC-SIGN and gp120 which may prevent early HIV-1 infection.
DC-SIGN; gp120; High-throughput screening assay
In Lagos, Nigeria, Médecins Sans Frontières (MSF) and the Ministry of Health (MoH) commenced free antiretroviral treatment (ART) in a hospital-based clinic. We performed a cross-sectional study to compare factors associated with raised viral load between patients with (“experienced”) and without (“naïve”) prior antiretroviral (ARV) exposure at commencement of ART at the clinic. We also examined factors influencing ARV adherence in experienced patients prior to clinic entry.
We included adult patients receiving ART from MSF who answered a questionnaire about previous antiretroviral use. Multivariate logistic regression was used to estimate odds ratios (OR) for raised viral load (≥1000 copies/mL).
1246 (96%) patients answered: 1075 (86%) reported no, and 171 (14%) some, prior ARV exposure. ARV-naïve patients were more immunosuppressed at baseline: 65% vs 37% (p<0.001) had CD4<200; 17% vs 9% (p = 0.013) were WHO stage 4. Proportionately more experienced than naïve patients had raised viral loads (20% vs 9%, p<0.001) on ART in the MSF/MoH clinic. Raised viral load was associated with prior ARV experience (adjusted OR = 3.74, 95%CI 2.09–6.70, p<0.001) and complete interruption of current ART (adjusted OR = 3.71, 95%CI 2.06–6.68, p<0.001). Higher CD4 at time of VL and a higher self-rated score of recent adherence were associated with lower OR of a raised viral load. Among experienced patients who missed pills before joining MSF/MoH, most common reasons were because ARVS were not affordable (58%) or available (33%), with raised viral load associated with being unsure how to take them (OR = 3.16, 95%CI 1.10–9.12, p = 0.033).
Patients previously exposed to ARVs had increased OR of raised viral load. The cost and availability of ARVs were common reasons for missing ARVs before joining the MSF/MoH clinic, and inadequate patient knowledge was associated with raised viral load.