Characterization of a mouse neuropathic pain model caused by the highly active antiviral therapy (HAART) Stavudine

BACKGROUND

Although highly active antiviral therapies (HAART) exert control over viral replication in persons with Acquired Immunodeficiency Syndrome (AIDS), neuropathic pain is a side effect. Symptoms include hyperalgesia and allodynia. Stavudine, also known as D4T, is a HAART used to treat Human Immunodeficiency Virus (HIV). This study examined the extent to which D4T produces neuropathic pain and examined pharmacological management with a standard opioid analgesic.

METHODS

Male and female C57BL/6 J mice were injected intraperitoneally with one dose of vehicle or D4T (10-56 mg/kg). Mice were tested through day 92 post injection for mechanical allodynia, assessed with von Frey filaments, and thermal hyperalgesia, assessed via the hotplate test. Separate cohorts received vehicle or 56 mg/kg D4T, the presence of allodynia and thermal hyperalgesia confirmed, and mice received intraperitoneal vehicle, morphine, or 0.032 mg/kg naltrexone + morphine.

RESULTS

D4T produced dose- and time-dependent mechanical allodynia and thermal hyperalgesia. The smallest effective D4T dose was 17.8 mg/kg. This dose produced mechanical allodynia but not thermal hyperalgesia. Larger D4T doses (32 and 56 mg/kg) produced mechanical allodynia and thermal hyperalgesia lasting 92 days. Morphine dose-dependently alleviated both mechanical allodynia and thermal hyperalgesia in D4T-treated mice with ED50 values of 4.4 and 1.2 mg/kg, respectively. Naltrexone produced a rightward shift of the morphine dose-response function, i.e., increased the ED50 value of morphine by at least 3.8-fold.

CONCLUSION

Stavudine produced neuropathic pain as a function of dose and time in mice. Opioid analgesics appear to be effective in alleviating neuropathic pain in a D4T-induced mouse model.

Motives for change of first-line antiretroviral therapy regimens in an unselected cohort of HIV/AIDS patients at a major referral centre in South-west Cameroon

OBJECTIVE

The rapid scale-up of antiretroviral therapy (ART) coverage in sub-Saharan Africa has encountered the challenge of maintaining international clinical standards of ART utilization and change of ART regimens. In Cameroon, scarce reports have documented the motives for change of ART. This study had as objective to investigate the reasons for switch in ART through a secondary analysis and descriptive synthesis of data from a cross-sectional study at the Limbe Regional Hospital.

RESULTS

One hundred participants were included. Their mean age was 40.2 ± 8.0 years and 70% of them were females. The median duration of ART use was 60 months. Zidovudine-Lamivudine-Nevirapine regimen was received by 83% of patients while the Stavudine-Lamivudine-Nevirapine regimen had the highest median duration of use (58 months). Most patients had experienced changes in ART (especially from Stavudine-Lamivudine-Nevirapine regimen) with the chief reason being unavailability of their previous regimens. Four patients had their ART changed due to active tuberculosis, 4 due to pregnancy and 7 due to ART toxicity (4 and 3 for peripheral neuropathy and lipodystrophy respectively). In conclusion, shortages in ART hugely influenced switch in regimens. In such a context, modifications in ART possibly deviate from guidelines with resultant sub-optimal therapy and enhanced drug resistance.

A retrospective case-cohort study comparing treatment outcomes in abacavir versus stavudine containing first line antiretroviral treatment regimens in children <3yrs old, at a paediatric programme based in Soweto, South Africa

Introduction

The current World Health Organization guideline for first line antiretroviral therapy (ART) in HIV-infected children recommends the use of abacavir and lamivudine as nucleoside backbones and no longer includes stavudine. We compared treatment outcomes with abacavir (ABC) versus stavudine (d4T) in a cohort of HIV-1 infected children 6 and 12 months after antiretroviral therapy was initiated.

Methods

This was a retrospective case-cohort study, using programmatic data from children enrolled in the Paediatric Wellness Programme at the Perinatal HIV Research Unit in Soweto, South Africa between 2005 and 2013. Children on abacavir/stavudine who had initiated ART at age <3 years with a regimen including lamivudine and lopinavir/ritonavir and had at least one 6 or 12 month viral load result were eligible. All ABC cases identified were matched for age at ART initiation and gender to eligible d4T controls (1:2). Outcomes analysed at 6 and 12 months post ART initiation included virological failure, mortality, immunological failure and anthropometry. Chi-square tests compared categorical measures while Kruskal-Wallis compared continuous measures.

Results

We identified 57 eligible ABC cases and selected 114 matched d4T controls. Overall, 57% were females and 89% started treatment at age <1year. The median age at ART initiation was 3.11 (IQR: 1.98–6.05) months. There was no difference in the proportion of children virologically suppressed between the groups at 6 (ABC 54.5% vs. d4T 67.0%, p = 0.125) and 12 (ABC 66.7% vs. d4T 71.6%, p = 0.53) months post ART-initiation. The proportion of children with adherence levels >90% for ABC and d4T were similar too (95% in ABC vs. 86% in d4T, p = 0.10). The proportion of children who died over 12 months was 3.5% in the ABC and 7.9% in the d4T group (p = 0.27). Similarly, the anthropometric measures were comparable.

Conclusions

It is reassuring that in the short term, in this group of patients, the treatment outcomes were similar.

First-line antiretroviral drug discontinuations in children

Introduction

There are a limited number of paediatric antiretroviral drug options. Characterising the long term safety and durability of different antiretrovirals in children is important to optimise management of HIV infected children and to determine the estimated need for alternative drugs in paediatric regimens. We describe first-line antiretroviral therapy (ART) durability and reasons for discontinuations in children at two South African ART programmes, where lopinavir/ritonavir has been recommended for children <3 years old since 2004, and abacavir replaced stavudine as the preferred nucleoside reverse transcriptase inhibitor in 2010.

Methods

We included children (<16 years at ART initiation) who initiated ≥3 antiretrovirals between 2004–2014 with ≥1 follow-up visit on ART. We estimated the incidence of first antiretroviral discontinuation using Kaplan-Meier analysis. We determined the reasons for antiretroviral discontinuations using competing risks analysis. We used Cox regression to identify factors associated with treatment-limiting toxicity.

Results

We included 3579 children with median follow-up duration of 41 months (IQR 14–72). At ART initiation, median age was 44 months (IQR 13–89) and median CD4 percent was 15% (IQR 9–21%). At three and five years on ART, 72% and 26% of children respectively remained on their initial regimen. By five years on ART, the most common reasons for discontinuations were toxicity (32%), treatment failure (18%), treatment simplification (5%), drug interactions (3%), and other or unspecified reasons (18%). The incidences of treatment limiting toxicity were 50.6 (95% CI 46.2–55.4), 1.6 (0.5–4.8), 2.0 (1.2–3.3), and 1.3 (0.6–2.8) per 1000 patient years for stavudine, abacavir, efavirenz and lopinavir/ritonavir respectively.

Conclusions

While stavudine was associated with a high risk of treatment-limiting toxicity, abacavir, lopinavir/ritonavir and efavirenz were well-tolerated. This supports the World Health Organization recommendation to replace stavudine with abacavir or zidovudine in paediatric first-line ART regimens in order to improve paediatric first-line ART durability.

Gold Nanocarriers for Macrophage-Targeted Therapy of Human Immunodeficiency Virus

The human immunodeficiency virus (HIV) continues to be a global pandemic and there is an urgent need for innovative treatment. Immune cells represent a major target of virus infection, but are also therapeutic targets. Currently, no antiretroviral therapy targets macrophages, which function as portal of entry and as major long-term deposit of HIV. It has been shown before that human macrophages efficiently internalize gold nanoparticles, a fact which might be used to target them with drug-nanoparticle conjugates. Here, the authors use gold nanocarriers to facilitate delivery of stavudine, a widely used antiretroviral drug, to primary human macrophages. Using an ease-of-use coupling method, a striking potentiation of stavudine intake by macrophages using gold nanocarriers is shown. Further, the carriers induce a specific subtype of proinflammatory activation indicative for antiviral activity of macrophages, which suggests promising novel treatment options for HIV.

Prevalent neuropathy in a cohort of HIV-infected Kenyan sex workers using antiretroviral drugs

INTRODUCTION

Several risk factors including stavudine and age have been strongly associated with polyneuropathy. However, conflicting data exist on height as an independent risk factor in polyneuropathy. The objective of this study is to exclude height as an independent polyneuropathy risk factor in a cohort of human immunodeficiency virus (HIV)-infected Kenyan sex workers.

METHODS

This was an analysis of prospectively collected data of treatment-naive subjects initiating either stavudine or tenofovir diphosphate fumarate or zidovudine-based antiretroviral therapy (ART) regimens from January 2008 to August 2012. Polyneuropathy was characterised as burning sensation, numbness, or dysesthesia. The study used arithmetic means of weight (kg) and height (cm) measured in duplicates using calibrated scales.

RESULTS

After exclusion of duplicate data sets and un-confirmed cases of polyneuropathy, the study identified 212 patients without polyneuropathy, 14 pre-ART and 94 post-ART related polyneuropathy cases. Polyneuropathy cases were older but did not differ in demographic, clinical and laboratory parameters at baseline. There was a significant difference in first-line ART regimens with more patients on tenofovir disoproxil fumarate in the post-ART group (p=0.017).

CONCLUSION

Polyneuropathy is a common disorder among HIV-infected Kenyan sex workers. These data cannot support the postulated increased risk by height after matching for gender and ART duration. Though stavudine is associated with polyneuropathy, in this study many patients previously not exposed to stavudine developed polyneuropathy. This suggests the involvement of unknown risk factors such as genetic and metabolite differences in the development of polyneuropathy.

Pharmacokinetics of nevirapine, stavudine and lamivudine in Indian HIV-infected children receiving generic fixed dose combinations

OBJECTIVE

To determine the trough and two hour plasma levels of nevirapine, stavudine, and lamivudine when administered in fixed dose combinations (FDC).

DESIGN

Cross sectional.

SETTING

Tertiary care hospital in Northern India.

PARTICIPANTS

79 HIV-infected children receiving antiretroviral therapy with FDCs for more than month.

INTERVENTION

Two-point sampling (0 and 2 hours after the morning dose).

OUTCOME MEASURES

Plasma concentrations of all three drugs were simultaneously assayed by liquid chromatography/mass spectroscopy.

RESULTS

Majority (77%) of children were receiving fixed dose combination of stavudine, lamivudine, nevirapine in the ratio of 6:30:50 mg. The median (IQR) trough and 2-hour plasma levels (µg/mL) of nevirapine, stavudine and lamivudine were 5.2 (4.0, 6.3) and 7.9 (6.0, 9.7); 0.1 (0.06, 0.16) and 1.1 (0.59, 1.6); 0.1 (0.02, 0.2) and 2.5 (1.4, 3.1), respectively. Very few children had sub-therapeutic plasma drug levels of stavudine (2.5%), lamivudine (7.6%) and nevirapine (10%). Inadequate viral suppression at 6 months follow up was significantly associated with initial high viral load, low CD4 percentage at the time of enrolment in study, and lower doses of lamivudine and stavudine.

CONCLUSIONS

The currently available generic pediatric fixed dose antiretroviral combinations in India provide adequate drug exposure in majority of children.

Efficacy and Safety of Abacavir Plus Lamivudine Versus Didanosine Plus Stavudine When Combined with a Protease Inhibitor, a Nonnucleoside Reverse Transcriptase Inhibitor, or Both in HIV-1 Positive Antiretroviral-Naive Persons

PURPOSE

The combination of abacavir + lamivudine (ABC+3TC) versus didanosine + stavudine (ddI+d4T), each combined with other classes of antiretrovirals (ARVs) in ARV-naive patients, was compared for the combined endpoint of time to plasma HIV RNA >50 copies/mL (at or after the 8-month visit) or death (primary endpoint) in a nested substudy of an ongoing multicenter randomized trial.

METHOD

The substudy enrolled 182 patients; mean HIV RNA and CD4+ cell counts at baseline were 5.1 log10 copies/mL and 212 cells/mm3, respectively.

RESULTS

After a median follow-up of 28 months, rates of primary endpoint were 57.2 and 67.8 per 100 person-years for the ABC+3TC and ddI+d4T groups (hazard ratio [HR]=0.81, 95% confidence interval [CI] 0.58-1.14, p=.23).

CONCLUSION

There was a trend for treatments containing ABC+3TC to be better than treatments containing ddI+d4T with respect to HIV RNA decreases, CD4+ cell count increases, and tolerability.

Reductions in Stavudine Dose Might Ameliorate Mitochondrial-Associated Complications Without Compromising Antiviral Activity

BACKGROUND

Stavudine (d4T) is a nucleoside analogue approved for the treatment of HIV infection. Concern has risen due to its association with mitochondrial toxicity. Given that the toxicity might be dose-dependent, we explored prospectively whether lowering d4T doses might improve the safety profile of the drug without compromising its antiviral activity.

METHOD

All HIV-infected patients seen at our institution during the first semester of year 2003 who were receiving a d4T-containing regimen and had plasma HIV RNA below 50 copies/mL for the previous 3 months were invited to participate in a trial in which half of patients reduced the dose of d4T from 40 to 30 mg bid (cases) and the other half continued with the same d4T dose (controls).

RESULTS

A total of 92 patients were recruited in the study: 47 cases and 45 controls. A total of 9 patients experienced virological failure during the following 12 months: 4 cases and 5 controls. No significant differences between groups were recognized for mean transaminase levels, cholesterol, triglycerides, and lactate at baseline nor over the 12-month follow-up period. Lipodystrophy was recognized in 20% of patients at baseline, without significant differences between groups, and no significant improvements were recognized in the d4T 30 mg bid arm after 12 months follow-up. However, a median significant increase of 2.23-fold in the mitochondrial DNA content in peripheral blood mononuclear cells (PBMCs) was recognized in a subset of 11 patients who reduced the d4T dose, whereas it remained unchanged in 10 controls.

CONCLUSION

A reduction in the d4T dose from 40 to 30 mg bid may ameliorate mtDNA depletion in PBMCs without compromising the antiviral activity of the drug. However, significant improvements on surrogate laboratory markers of mitochondrial toxicity or in lipoatrophy could not be recognized over 12 months follow-up.

Progression of Lipodystrophy (LD) with Continued Thymidine Analogue Usage: Long-Term Follow-Up from a Randomized Clinical Trial (The PIILR Study)

PURPOSE

During the 24-week PIILR study of protease inhibitor (PI) withdrawal, improved lipids and reduction in intraabdominal visceral fat was seen, however, there was also a loss of subcutaneous limb fat in patients with HIV-lipodystrophy (LD). It was hypothesized that overall improvement in LD may require a longer period of time off PIs.

METHOD

Follow-up of patients randomized to stop or continue PI-based therapy for 24 weeks, in a multicenter study, was continued for up to 120 weeks. Biochemistry and lipid parameters were assessed every 3 months. DEXA and CT scans were performed annually. Limb fat, visceral adipose tissue, and the lipodystrophy case definition score (LCDS) were used as indicators of LD severity.

RESULTS

Forty-five male patients with baseline and week 120 body composition data were assessed. There were no significant changes in the limb fat or visceral adipose tissue (VAT) components of LD, with the exception of the LCDS (change from baseline +5.79, p < .001). Control of viral replication was maintained and lipid and glycemic parameters were unchanged over the 120-week follow-up. Linear regression analysis showed on-study usage of stavudine was independently and significantly correlated with both decreased limb fat mass and a higher LCDS.

CONCLUSION

Body composition or metabolic features of LD did not improve over 2 years of observation in patients remaining on predominantly PI-sparing therapy. LD was adversely influenced by continued stavudine use.

Changes in Body Fat Measured by DEXA in Patients Taking Different Formulations of Stavudine

BACKGROUND

Lipoatrophy is a frequent complication of chronic stavudine therapy. Stavudine extended release formulation (stavudine ER) gives lower peak and higher trough levels than the immediate release formulation (stavudine IR), and we hypothesized that the lower peak might result in less lipoatrophy.

OBJECTIVE

To compare the rate of peripheral lipoatrophy between patients taking stavudine ER and stavudine IR.

METHOD

Body composition was measured by dual energy X-ray absorptiometry (DEXA) every 6 months for 18 months in 29 patients taking either stavudine ER or IR as part of a randomized controlled clinical trial.

RESULTS

DEXA fat measurements did not differ between the ER and IR groups at baseline, after a median of 32 months on stavudine-containing treatment. Over the 18 months of follow-up in the whole cohort limb fat decreased by a mean of 0.29 +/- 0.50 kg (p = .01) and leg fat percent decreased by a mean of 1.23% +/- 1.92% (p = .001), whereas trunk fat and trunk-to-limb fat percent ratio did not change significantly. There was no significant difference between the ER and IR groups in the rate of change of any of the fat parameters. At study completion, the proportion of patients with clinical lipodystrophy was similar in the stavudine ER and stavudine IR groups (67% and 64%, respectively; p = .893).

CONCLUSION

Stavudine ER does not appear to cause less peripheral lipoatrophy.

Comparison of Two Once-Daily Regimens with a Regimen Consisting of Nelfinavir, Didanosine, and Stavudine in Antiretroviral Therapy-Naïve Adults: 48-Week Results from the Antiretroviral Regimen Evaluation Study (ARES)

BACKGROUND

To improve the dosing frequency and pill burden of antiretroviral therapy, we compared two once-daily dosed regimens to a twice-daily dosed regimen.

METHOD

HIV-1-infected, antiretroviral drug-naïve adults were randomized to either twice-daily nelfinavir and stavudine and once-daily didanosine (regimen A) or simplified once-daily dosed antiretroviral regimens consisting of nevirapine, didanosine, and lamivudine (regimen B) or saquinavir, ritonavir, didanosine, and lamivudine (regimen C).

RESULTS

At 48 weeks of therapy, the proportion of patients with a blood plasma HIV-1 RNA concentration (pVL) <50 copies/mL by intention-to treat analysis was 42.3%, 50.0%, and 56.5% for regimens A (n = 26), B (n = 22), and C (n = 23), respectively. The time to a pVL <50 copies/mL for the first time was significantly shorter in regimen C, and there was significantly more progression to CDC events in regimen B. These differences are possibly due to differences in baseline characteristics. Adverse events were lowest for regimen C; more signs associated with mitochondrial toxicity occurred in regimen A. Increase in CD4 count was comparable between arms.

CONCLUSION

No statistically significant difference in efficacy was found between the two investigated once-daily dosed treatment regimens (B and C) and the reference (A). Regimen C possibly had a better virological response and less toxicity than regimens A and B.

Low dose versus high dose stavudine for treating people with HIV infection

BACKGROUND

Stavudine remains a component of combination antiretroviral therapy (ART) in resource-constrained countries due to its relatively low cost despite the WHO recommendation for its phasing out as a strategy to reduce stavudine associated toxicities. Where stavudine is still in use, it is recommended at a dose lower than the standard dose in order to reduce stavudine related toxicity.

OBJECTIVES

To compare the safety and virologic efficacy of low dose versus high dose stavudine for treating HIV-1 infection.

SEARCH METHODS

The comprehensive search strategy developed by the Cochrane HIV/AIDS Review Group was used to identify randomised controlled trials that compared the use of low dose versus high dose stavudine. The last search was conducted in February 2014 and the searches covered the period 1996 to 2014.

SELECTION CRITERIA

Randomised controlled trials comparing the use of low dose and high dose stavudine as part of ART combination therapy for treating adults.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected eligible trials, assessed methodological quality of the included studies and completed data extraction and analysis.

MAIN RESULTS

The search identified 3952 abstracts which were scanned for relevance. Three trials met the inclusion criteria (Milinkovic 2007; McComsey 2008; Sanchez-Conde 2005). All three trials were conducted in developed countries, participants were ART experienced and all had sustained virologic suppression at baseline. A total of 157 participants were recruited to the trials. Sample sizes ranged from 24 to 92 and more than 79% of participants were male.The studies were at a high risk of selection, performance/detection and selective outcome reporting biases. Some baseline characteristics differed among the groups, including triglyceride levels in two studies and body mass index in one study. In light of variation in the design and follow-up of the study results, no meta-analysis was performed and the results of single studies are presented. There was no significant difference in virologic suppression in the included studies (Milinkovic 2007; McComsey 2008; Sanchez-Conde 2005); Risk Ratio (RR) 1.09 (95% CI: 0.93 to 1.28), 0.94 (95% CI:0.59 to 1.50) and 1.03 (95% CI: 0.90 to 1.18) respectively. Symptomatic hyperlactatemia was seen in the high dose arm of the Milinkovic 2007 study; RR 0.21 (95% CI: 0.01 to 4.66), in no participants in the McComsey 2008 trial and not reported on in the Sanchez-Conde 2005 trial. McComsey 2008 and Milinkovic 2007 demonstrated a reduction in bone mineral density (BMD), reduction in limb fat and an increase in triglycerides in the high dose arms. The studies did not indicate that any participants discontinued treatment due to adverse events.

AUTHORS' CONCLUSIONS

This systematic review identified only three small trials that evaluated virologic efficacy and safety of high dose versus low dose stavudine. All three trials were conducted in developed countries and none reported from developing countries yet stavudine remains a component of ART combination therapy in many developing countries. It was not possible to perform a meta-analysis on these trails. Individual results from the trials were imprecise and have not identified a clear advantage in virologic efficacy or safety between low and high dose stavudine. Furthermore, enrolled participants were treatment experienced with sustained virologic suppression and so existing data cannot be generalized to settings where stavudine is currently used in ART naive patients with high viral loads. Stavudine dose reduction trials in ART naive patients, in developing countries where stavudine is still being used are warranted as the phasing out of stavudine that is recommended by WHO may not be immediately universally feasible.

Hepatitis B and C co-infection among HIV-infected adults while on antiretroviral treatment: long-term survival, CD4 cell count recovery and antiretroviral toxicity in Cambodia

Background

Despite the high burden, there is a dearth of (long-term) outcome data of hepatitis B virus (HBV) and hepatitis C virus (HCV) co-infected patients receiving antiretroviral treatment (ART) in a clinical setting in resource-constrained settings, particularly from Asia.

Methods

We conducted a retrospective cohort study including all adults initiating standard ART (non-tenofovir-based) between 03/2003 and 09/2012. HBV infection was diagnosed by HBV surface antigen detection. HCV diagnosis relied on antibody detection. The independent effect of HBV and HCV on long-term (≥5 years) ART response in terms of mortality (using Cox regression), severe livertoxicity (using logistic regression) and CD4 count increase (using mixed-effects modelling) was determined.

Results

A total of 3089 adults were included (median age: 35 years (interquartile range 30–41); 46% male), of whom 341 (11.0%) were co-infected with HBV and 163 (5.3%) with HCV. Over a median ART follow-up time of 4.3 years, 240 individuals died. Mortality was 1.6 higher for HBV co-infection in adjusted analysis (P = 0.010). After the first year of ART, the independent mortality risk was 3-fold increased in HCV co-infection (P = 0.002). A total of 180 (5.8%) individuals discontinued efavirenz or nevirapine due to severe livertoxicity, with an independently increased risk for HBV (hazard ratio (HR) 2.3; P<0.001) and HCV (HR 2.8; P<0.001). CD4 recovery was lower in both HBV and HCV co-infection but only statistically significant for HBV (P<0.001).

Discussion

HBV and HCV co-infection was associated with worse ART outcomes. The effect of early ART initiation and providing effective treatment for hepatitis co-infection should be explored.

An antiretroviral regimen containing 6 months of stavudine followed by long-term zidovudine for first-line HIV therapy is optimal in resource-limited settings: a prospective, multicenter study in China

BACKGROUND

An zidovudine (AZT)-substitution regimen containing 24-week stavudine (d4T) followed by long-term AZT for HIV therapy is potential to trade off short-term AZT-related anemia and long-term risks associated with d4T in resource-limited settings. However, evidence is scarce. This study aims to assess the efficacy and safety of AZT-substitution regimen, aiming to find a regimen with better efficacy, less adverse events, and more affordability in resource-limited settings.

METHODS

This prospective, multicenter study enrolled 499 (190 on d4T regimen, 172 on AZT regimen, and 137 on AZT-substitution regimen) HIV-1-infected subjects who initiated combined antiretroviral therapy and attended follow-up visits over 96 weeks from 2009 to 2011. Lamivudine (3TC) and either nevirapine (NVP) or efavirenz (EFV) were the other two drugs in the antiretroviral regimens. Virologic and immunologic responses and adverse events were monitored at baseline and at weeks 4, 12, 24, 36, 48, 60, 72, 84, and 96.

RESULTS

In terms of hematological adverse effects, AZT-substitution group had similar safety profiles to d4T group and was superior to AZT group. In comparison with AZT-substitution group, AZT group was associated with higher risk of developing anemia (adjusted hazard ratio (aHR) for anemia ≥ grade II, 8.44, 95% CI 1.81-39.46) and neutropenia (aHR for neutropenia ≥ grade II, 1.86, 95% CI 1.19-2.93). The prevalence of lipodystrophy in d4T group was 19.5%, while that in AZT-substitution group was zero. As to antiretroviral efficacy, these three groups showed no differences.

CONCLUSION

AZT-substitution regimen provides a relatively safe and effective first-line antiretroviral strategy in resource-limited settings.

Initiation of antiretroviral therapy before 6 months of age is associated with faster growth recovery in South African children perinatally infected with human immunodeficiency virus

OBJECTIVE

To describe the effects of age at antiretroviral therapy (ART) initiation on growth outcomes among children infected with HIV followed for 48 months after treatment initiation.

STUDY DESIGN

This secondary analysis describes anthropometric changes in children infected with HIV in Johannesburg, South Africa who initiated ritonavir-boosted lopinavir-based ART before 24 months of age and were randomized to continue ritonavir-boosted lopinavir or to receive nevirapine after achieving and maintaining virologic suppression. Weight, height, and head circumference were measured at visits over 48 months post-ART initiation. Growth patterns including weight-for-age z-scores (WAZs), height-for-age z-scores, body mass index-for-age z-scores, and head circumference for age z-score were compared between children initiating ART<6 months, 6-12 months, and 12-24 months of age.

RESULTS

A total of 195 children (mean±SD age 10.7±5.9 months), including 54 (27.7%)<6 months, 69 (35.4%) 6-12 months, and 72 (36.9%) 12-24 months of age at ART initiation, were evaluated. In the first 12 months on treatment, children<6 months of age at ART initiation experienced more rapid improvement in WAZ (1.98 vs 1.44, P=.084) and head circumference for age z-score (1.24 vs 0.45, P=.004) than children who initiated ART between 12-24 months of age. By 48 months on ART, growth outcomes were similar, regardless of age at ART initiation. WAZ approached population norms by 12 months on ART. Although improving, height-for-age z-scores remained on average 1.0 z-score below population norms at 48 months of therapy.

CONCLUSIONS

Initiation of ART before 6 months of age results in more rapid growth recovery in children infected with HIV. These data provide further evidence for the importance of prompt diagnosis and early initiation of ART for infants infected with HIV.

A Combined-Formulation Tablet of Lamivudine/Nevirapine/Stavudine: Bioequivalence Compared With Concurrent Administration of Lamivudine, Nevirapine, and Stavudine in Healthy Indian Subjects

Generic fixed-dose combinations of antiretrovirals are frequently prescribed for the treatment of human immunodeficiency virus infection. A randomized, 2-way study was conducted in 24 fasting, healthy, Indian male subjects to assess bioequivalence between a single combination tablet containing lamivudine, stavudine, and nevirapine (treatment A) with respect to separate marketed tablets administered simultaneously (treatment B). Each subject received treatments A and B separated by 19 days of a drug-free washout period. Plasma concentrations of antiretrovirals, determined by a validated liquid chromatography/tandem mass spectrometry assay, were used to assess pharmacokinetic parameters such as maximum observed plasma concentration and area under the plasma concentration curve. Pharmacokinetic parameters were comparable for either treatment. As geometric mean ratios (% treatment A/treatment B) of log-transformed parameters of area under the plasma concentration curve and plasma concentration, as well as their resultant 90% confidence intervals, were within 80% to 125% and 75% to 133%, respectively, 2 treatments were considered bioequivalent in the extent and rate of absorption. Both treatments exhibited similar tolerability under fasting conditions.

Baseline CD4 cell counts and outcomes among adult treatment naive HIV patients after taking fixed dose combination GPO-VIR-S and GPO-VIR-Z in Thailand

A retrospective study was conducted by reviewing 459 medical records of adult treatment naive HIV patients who received a fixed dose combination of GPO-VIR-S (stavudine, lamivudine and nevirapine) or GPO-VIR-Z (zidovudine, lamivudine and nevirapine) at Ramathibodi Hospital in Bangkok, Thailand during 2002-2009 following Thai National Treatment Guideline for adults with HIV. The aim of this study was to assess the association between the baseline CD4 cell count and outcome. The median CD4 cell count at baseline, 6, 12 and 102 months were 102 cells/microl, 213 cells/microl, 274 cells/microl and 423 cells/microl. The virologic response (p=0.327), virologic rebound (p=0.626), adverse effects of anti-retroviral therapy (ART) (p=0.976), switching to other ART (p=0.245), occurrence of immune reconstitution inflammatory syndrome (IRIS) (p>0.05) and occurrence of drug resistance (p=0.952) were not significantly associated with baseline CD4 count. The Kaplan-Meier estimate showed the median time (95% CI) to achieve virologic response was 10.4 (9.8-11.0) months and the median time to achieve virologic rebound was 30.0 (21.6-38.4) months after initiation of ART. Analysis showed the median time to achieved virologic response (p=0.401) and virologic rebound (p=0.562) were not significantly associated with the baseline CD4 count. This study shows the outcome after onset of ART did not vary by baseline CD4 cell count.

Pharmacokinetics of nevirapine in HIV-infected infants weighing 3 kg to less than 6 kg taking paediatric fixed dose combination tablets

OBJECTIVES

To evaluate pharmacokinetics of nevirapine, lamivudine and stavudine in HIV-infected Zambian infants receiving fixed dose combination (FDC) antiretroviral tablets (Triomune Baby).

DESIGN

Phase I/II study.

METHODS

Sixteen HIV-infected children at least 1 month, weighing 3 kg to less than 6 kg were enrolled. Blood was sampled at t = 0, 2, 6 and 12 h after observed intake of one FDC tablet (50 mg nevirapine, 6 mg stavudine, 30 mg lamivudine) 4 weeks after starting treatment. Safety and viral load response over 48 weeks were determined.

RESULTS

The median [interquartile range (IQR)] age, body weight and daily nevirapine dose in 15 included children (eight girls) were 4.8 (4.2, 8.4) months, 5.3 (4.3, 5.5) kg and 348 (326 385) mg/m, respectively. The median (IQR) nevirapine area under the concentration-time curve (AUC0-12 h), Cmax and C12 h were 70 (56, 104) h mg/l, 7.5 (6.2, 10) mg/l, and 4.3 (2.9, 6.9) mg/l, respectively. Values were on average higher than reported in adults, but approximately 20% lower than previously reported in children weighing at least 6 kg. Four of 15 (27%) children had a subtherapeutic nevirapine C12 h (defined as <3.0 mg/l) compared to only three of 63 (5%) children weighing at least 6 kg (P = 0.02), whereas children aged less than 5 months [three of six (50%)] may have the highest risk for subtherapeutic nevirapine C12 h (P = 0.24). No association was found between viral load values and nevirapine plasma pharmacokinetic parameters (P > 0.3). Stavudine-lamivudine pharmacokinetic parameters were broadly comparable to heavier children.

CONCLUSION

Exposure to nevirapine in African, HIV-infected infants with low body weight taking FDC tablets appears on average to be adequate, but due to large intersubject variability a relatively high proportion had subtherapeutic nevirapine C12 h levels, particularly those aged less than 5 months.

The long-term effectiveness of generic adult fixed-dose combination antiretroviral therapy for HIV-infected Ugandan children

BACKGROUND

Access to pediatric antiretroviral formulations is increasing in resource-limited countries, however adult FDCs are still commonly used by antiretroviral therapy (ART) programs.

OBJECTIVE

To describe long-term effectiveness of using adult FDC of d4T+3TC+NVP (Triomune) in children for HIV treatment.

METHODS

Clinical, immunologic, and virologic outcomes of HIV-infected ART-naïve children aged six months to 12 years, were evaluated up to 96 weeks post-ART initiation.

RESULTS

From March 2004 to June 2006, 104 children were followed with a median age of 5.4 years, median CD4 cell percent and HIV-1 RNA were 11.0% (IQR 6.7-13.9) and 348,846copies/mL (IQR 160,941-681,313) respectively at baseline. Using Kaplan-Meir estimates, 75% of children had undetectable viral loads (<400copies/mL) at 96 weeks of ART. Children with a baseline CD4 cell percent >15% were 3 times more likely to achieve viral load <400copies/mL than those with baseline CD4 cell percent <5% after adjusting for baseline age {aHR = 3.03 (1.10-8.32), p=0.03}; no difference was found among those with CD4 cell percent >5-14.9% and <5%.

CONCLUSION

Treatment with generic adult FDC for HIV-infected Ugandan children led to sustained clinical, immunologic and virologic response during 96 weeks of ART. Early initiation of ART is key to achieving virological success.

Antiretroviral therapy interruptions result in loss of protective humoral immunity to neoantigens in HIV-infected individuals

OBJECTIVE

Sustained antiretroviral therapy (ART)-mediated viral suppression restores responses to vaccination in HIV-1-infected individuals. As ART interruption occur frequently in resource-constrained settings, we studied their effects on the ability to mount humoral immune responses against a neoantigen.

DESIGN

Treatment-naive HIV-1-infected individuals were treated with stavudine, lamuvidine and lopinavir/ritonovir. Individuals who maintained viral load less than 50  copies/ml and CD4 T-cell counts more than 450  cells/μl for 6 months received three doses of rabies vaccine, and were randomized to 72 weeks of continuous ART (arm 1) or sequential 2, 4 and 8-week ART interruptions (arm 2). An additional vaccine dose was administered at study end.

METHODS

Neutralizing antibody titers to rabies virus were assessed in plasma with a rapid fluorescent focus-inhibiting test.

RESULTS

The proportion of participants achieving protective (>0.5 IU/ml) antibody titer after vaccination was similar (arm 1=92%; arm 2=91%), but over time the cumulative proportion of observations with protective titer was greater in arm 1 than arm 2 (P=0.0177). From week 26 after vaccination, antibody titers were lower in arm 2 than arm 1, and volunteers in arm 2 lost protective antibody titers at a greater rate (P=0.0029). After boosting, 100% of arm 1 and 95% arm 2 volunteers achieved protective antibody titer.

CONCLUSION

Our data indicate that individuals undergoing recurring ART interruption retain lower neutralizing antibody titers to a neoantigen, but maintain the ability to mount secondary responses upon boosting, suggesting that they might benefit from vaccine schedule intensification.

The role of nucleoside reverse transcriptase inhibitors usage in the incidence of hyperlactatemia and lactic acidosis in HIV/AIDS patients

Hyperlactatemia and lactic acidosis (LA) are among the most dangerous and life-threatening side effect that occurs during therapy with some nucleoside reverse transcriptase inhibitors (NRTIs), mainly didanosine (ddI) and stavudine (d4T), also known as d-drugs. Therefore, we performed a prospective, follow-up study and aimed to examine the incidence rates (IR) and rate ratios (RR) of hyperlactatemia and LA for each NRTI. Three hundred and ninety-six HIV-patients were included in final analysis comprising 783.8 person-years of follow-up. Between 1st January 2000 and 1st January 2008, 19 cases of hyperlactatemia and 15 cases of LA were recorded. Between regimens with the significant impact for developing hyperlactatemia and LA the lowest IR was for didanosine (IR=2.87 per 100 person-years, 95%CI=0.45-9.25 and IR=4.31 per 100 person-years, 95%CI=1.07-13.91, respectively), and the highest for didanosine+stavudine (IR=10.17 per 100 person-years, 95%CI=1.02-19.76 and IR=7.39 per 100 person-years, 95%CI=1.02-13.05, respectively). Compared to didanosine alone the RR of hyperlactatemia was 2.67 (95%CI=1.11-12.52) for stavudine, and 4.06 (95%CI=1.31-15.48) for didanosine+stavudine. The RR of LA was 3.12 (95%CI=1.13-10.65) for stavudine, and 5.13 (95%CI=1.54-13.37) for didanosine+stavudine in comparison with didanosine alone. Other risk factors for AP were CD4 cell count less than 200 cells/mm³ and female sex. Our results suggest that the use of stavudine alone or in combination with didanosine should not be used as first-line therapy, especially in patients with CD4 cell count less than 200 cells/mm³ and females if other treatment options are available.

Investigation of the effect of Stalanev (Stavudine, Lamivudine and Nevirapine) treatment on plasma lactate levels in adults attending Beatrice Road and Wilkins Infectious Diseases Hospital Opportunistic Infections Clinics in Harare, Zimbabwe

MAIN OBJECTIVE

To evaluate the effect of Stalanev (Stavudine, Lamivudine and Nevirapine) treatment on plasma lactate levels in adults attending Beatrice Road Infectious Diseases Hospital and Wilkins Infectious Diseases Hospital Opportunistic Infections Clinics in Harare.

DESIGN

Prospective cohort study carried out between January and May 2011.

SETTING

Beatrice Road and Wilkins Infectious Diseases Hospital Opportunistic Infections Clinics in Harare, Zimbabwe.

PARTICIPANTS

A convenience sample of 180 ART naive HIV infected adults aged 20-68 years who were about to be initiated on STALANEV were recruited.

RESULTS

The mean plasma lactate at baseline was 1.57 mmol/L (SD 0.43). After two months on STALANEV, 25 participants (13.9%) had hyperlactatemia and the mean plasma lactate level was 1.99 mmol/L (SD 0.49). At four months follow up, 98 participants (54%) had hyperlactatemia and the mean plasma lactate level was 2.65 mmol/l (SD 0.55). Mean plasma lactate levels increased significantly from baseline to 2 months follow up and from 2 months follow up to 4 months follow up (p < 0.001). None of the participants developed lactic acidosis (plasma lactate > 3.5) after two months of follow up but 14 (7.8%) developed mild lactic acidosis and three (1.7%) had moderate lactic acidosis after four months on STALANEV.

CONCLUSIONS

Our findings are in agreement with those of other studies that reported that treatment with STALANEV leads to hyperlactatemia thereby posing a risk for the development of lactic acidosis in patients. In the absence of alternative regimens, we recommend routine monitoring of plasma lactate levels on all patients on STALANEV in Zimbabwe.

Lipid profile changes in Thai HIV and tuberculosis co-infected patients receiving non-nucleoside reverse transcriptase inhibitors-based antiretroviral therapy

OBJECTIVE

To study and compare the pattern of lipid profile changes in Thai HIV and tuberculosis (TB) co-infected patients after receiving two non-nucleoside reverse transcriptase inhibitors (NNRTIs)-based antiretroviral therapy (ART).

MATERIAL AND METHOD

From an open label, randomized, comparative trial comparing treatment outcome between HIV and TB co-infected patients receiving nevirapine (NVP) or efavirenz (EFV) combined with stavudine and lamivudine, patient's body mass index (BMI), CD4 cell count, plasma HIV-1 RNA, fasting blood glucose, plasma total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and triglyceride (TG) were collected at baseline, 24, and 48 weeks of ART.

RESULTS

Of the 121 patients included in the present study, mean (SD) age was 36.9 (8.4) years and 66% were male. After 48 weeks of ART the median (IQR) percentage of TC, LDL-C, HDL-C and TG values were 21.1% (5.4-40.7), 23.5% (-0.8-49.8), 22.7% (0-50) and -1.0% (-34.6-32.2) respectively. The median (IQR) percentage change of the HDL-C value was significantly higher in NVP-based than EFV-based ART (31.9 [9.6-50.0] vs. 12.2 [-8.8-51.2]; p = 0.03). The proportions of patients with high TC (21.5%) and high LDL-C (29.2%) increased and low HDL-C (11.6%) decreased significantly at 48 weeks of ART compared to baseline (all, p < 0.01). The proportions of patients with high TC, high TG and low HDL-C were significantly higher in the EFV group than in the NVP group (p = 0.03 for high TC, p = .01 for high TG and p < 0.01 for low HDL-C).

CONCLUSION

NNRTI-based ART is associated with increases of TC, LDL-C and HDL-C values in Thai HIV and TB co-infected patients. More favorable lipid profile is observed in NVP-based than EFV-based ART.

Effects of daily intake of zidovudine-stavudine on rat pregnancy outcome: biological essay

PURPOSE

To evaluate the effects at term of a highly active antiretroviral drug association when administered for the whole period of rat pregnancy.

METHODS

Forty pregnant rats weighing about 200 g were randomly divided into four groups: a control group (Ctr = drug vehicle control, n=10) and three experimental groups, which were treated with an oral solution of zidovudine-stavudine (Explx = 10/1 mg/kg b.w., n=10; Exp3x = 30/3 mg/kg b.w., n=10; Exp9x = 90/9 mg/kg b.w., n=10) from "day 0" up to the 20th day of pregnancy. Maternal body weights were recorded at the start of the experiment and on the 7th, 14th and 20th day thereafter. At term (20th day) the rats were anesthetized and submitted to hysterotomy. Implantations, reabsorptions, living fetuses, placentae and intrauterine deaths were looked for and recorded. The collected fetuses and placentae were weighed and the concepts were examined by a stereoscopic microscope looking for external malformations.

RESULTS

No significant alterations due to the antiretroviral drug treatment could be detected regarding the number of implantations, fetuses, placentae, absorptions and malformations nor regarding maternal and fetal mortality.

CONCLUSIONS

Administration of the association zidovudine/stavudine for the whole period of rat pregnancy did not interfere with the maternal, fetal and placental weight gain as well as abnormalities detectable by the employed methodology.

Toxicity associated with stavudine dose reduction from 40 to 30 mg in first-line antiretroviral therapy

Background

To compare the incidence and timing of toxicity associated with the use of a reduced dose of stavudine from 40 to 30 mg in first-line antiretroviral therapy (ART) for HIV treatment and to investigate associated risk factors.

Methods

Multicohort study including 23 HIV programs in resource-limited countries. Adults enrolled between January 2005 and December 2009. Four-year rates of all-cause and stavudine-specific toxicity were estimated. Multilevel mixed-effect Poisson and accelerated failure models were used to investigate factors associated with toxicity and timing of diagnosis.

Findings

A total of 48,785 patients contributed 62,505 person-years of follow-up. Rate of all-cause toxicity was 7.80 (95%CI 7.59–8.03) per 100 person-years, but varied greatly across sites (range 0.41–21.76). Patients treated with stavudine 40 mg had higher rates of toxicity (adjusted rate ratio [aRR] 1.18, 95%CI 1.06–1.30 during the first year of ART; and 1.51, 95%CI 1.32–1.71 during the second year). Women, older age, initial advanced clinical stage, and low CD4 count were associated with increased toxicity rate ratios. Timing of lipodystrophy and peripheral neuropathy diagnosis were 12% and 13% shorter, respectively, in patients treated with stavudine 40 mg than in those receiving 30 mg stavudine dose (P = 0.03 and 0.07, respectively).

Insterpretation

Higher rates of drug-related toxicity were reported in patients receiving stavudine 40 mg compared with 30 mg, and the time to toxicity diagnosis was shorter in patients treated with the higher dose. Higher rates of toxicity were observed during the first two years of ART.

Effectiveness of fixed-dose combination stavudine, lamivudine and nevirapine (GPO-VIR) for treatment of naïve HIV patients in Thailand: a 3-year follow-up

Generic fixed dose combination stavudine (d4T), lamivudine (3TC) and nevirapine (NVP), named GPO-VIR is recommended in the HIV treatment guidelines for Thailand. The long term effectiveness and adverse effects of this drug combination for the treatment of HIV were evaluated in an ambispective study at Bamrasnaradura Infectious Diseases Institute, Nonthaburi Province, Thailand from March 2002 to January 2006. A total of 152 adult treatment naive HIV patients who had received at least 12 months of GPO-VIR were enrolled. The median (IQR) CD4 cell count increased from 23 (8-94) cells/microl at baseline to 126 (38-180), 136 (98-189), 199 (141-255) and 334 (243-414) cells/microl at 3, 6, 12 and 24 months (p < 0.001), respectively. The median (IQR) percentage of body weights increased from baseline by 3.0% (0.3-6.3), 6.2% (2.2-9.3), 7.3% (3.9-10.9) and 8.1% (3.4-11.9) at 3, 6, 12 and 24 months, respectively and then remained at a plateau until the end of the 3-year study. The occurrence of new opportunistic infections decreased significantly (p < 0.001) with GPO-VIR treatment. Drug resistance occurred in 5 cases (3.3%) with a median (IQR) time of 18.0 (16.5-32.5) months to occurrence. Adverse effects included hypercholesterolemia (43.2%), lipodystrophy (35.5%), hypertriglyceridemia (25%), hypertension (13.1%), peripheral neuropathy (11.9%), hyperlactatemia (2.6%) and lactic acidosis (1.3%). Thirty-six patients (27%) switched from GPO-VIR to other anti-retroviral drugs regimens due to lipodystrophy. This study showed GPO-VIR had clinical and immunological benefits, but one-third of patients had adverse effects.

In silico study supports the efficacy of a reduced dose regimen for stavudine

Stavudine (d4T) is used extensively as part of HAART in resource poor settings, despite its toxicities. The revised WHO guidelines specify replacement of d4T with less toxic but more expensive drugs when feasible, and that d4T doses be standardized to 30 mg twice daily (bid) (irrespective of body-weight), from the approved 40 mg bid in adults (body-weight ≥60 kg). Therefore, an in silico population pharmacokinetic and biochemical model was utilized to compare relative efficacies of the two doses in humans. Assessment of predicted quartile ranges of simulated concentrations of the triphosphate of d4T suggested sufficient trough concentrations to inhibit wild type HIV-1 reverse transcriptase at the reduced dose, lending support to the revised WHO recommendations.

[Effects of daily administration of a stavudine/nelfinavir association on the fetuses and placentas of female albino rats]

PURPOSE

To evaluate the effect of administration of a stavudine/nelfinavir combination on the rat pregnancy by assessing maternal and concepts weights, as well as the number of implantations, fetuses, placentas, resorptions and maternal and fetal mortality.

METHODS

Forty adult pregnant Wistar rats of the EPM-1 strain were randomly divided into four groups: control (GCtrl--drug vehicle control, n=10), and three experimental groups, which were treated with an oral solution of stavudine/nelfinavir (ExpI--1/40 mg/kg b.w., n=10; ExpII--3/120 mg/kg b.w., n=10; ExpIII--9/360 mg/kg b.w., n=10) from day 0 to the 20th day of pregnancy. Maternal body weights were determined at the start of the experiment and on the 7th, 14th and the 20th day thereafter. At term (20th day) the rats were anesthetized and, upon laparotomy and hysterotomy, the number of implantations, resorptions, living fetuses, placentae and intrauterine deaths were recorded. The collected fetuses and placentae were weighed and the concepts were examined under a stereomicroscope for possible external malformations. Statistical analysis was performed by analysis of variance (ANOVA) complemented by the Kruskal-Wallis test (p<0.05).

RESULTS

There was a progressive and gradual increase in body weight during the course of pregnancy in all groups, which was more evident in the final period, but with no significant difference between groups. The mean number of fetuses, placentas, implantations, and fetal and placental weights showed no significant differences between groups. Also, no resorptions or external malformations were found in the experimental groups. However, between the 8th and 14th days of gestation, there was one case of maternal mortality in each experimental group.

CONCLUSIONS

The administration of a stavudine/nelfinavir combination had no deleterious effects on the concepts.

Stavudine entrapped lipid nanoparticles for targeting lymphatic HIV reservoirs

The main objective of present research study was to evaluate the potential of lipid nanoparticles for active delivery of an antiretroviral drug to lymphatic tissues. Stavudine entrapped drug loaded solid lipid nanoparticles (SLNs) were prepared and characterized for a variety of physicochemical parameters such as appearance, particle size, polydispersity index and zeta potential. The targeting potential of the prepared nanoparticles was investigated by carrying out ex vivo cellular uptake studies in macrophages which depicted several times enhanced uptake as compared to pure drug solution. Further, the lymphatic drug levels and organ distribution studies demonstrated efficiency of the developed nanoparticles for prolonged residence in spleenic tissues. Thus it was concluded that stavudine entrapped lipid carriers can be exploited for effective and targeted delivery to cellular and anatomical HIV reservoirs and may ultimately increase the therapeutic safety and reduce side effects.

Regional adipose tissue measured by MRI over 5 years in HIV-infected and control participants indicates persistence of HIV-associated lipoatrophy

OBJECTIVE

Peripheral fat loss and visceral fat gain have been reported in HIV infection. There are limited data on long-term change in adipose tissue in HIV-infected patients vs. controls. Therefore, we determined change in regional adipose tissue from baseline examination to 5 years later among participants in the study of Fat Redistribution and Metabolic Change in HIV Infection.

METHODS

Regional adipose tissue volume was measured using MRI at both examinations in 477 HIV-infected and 214 control men and women. Lipoatrophy was defined as leg subcutaneous adipose tissue (SAT) below the cutoff point marking the lowest decile (10%) of controls at each examination.

RESULTS

HIV-infected and control participants showed similar adipose tissue gains. In men, all SAT depots and visceral adipose tissue started lower and remained lower on average in HIV-infected vs. controls. In women, leg and arm SAT also started lower and remained lower in HIV-infected vs. controls. Mean leg SAT of HIV-infected men was 67% of control men at baseline and 65% at follow-up; for women 83% and 77%. At baseline, 48% of HIV-infected participants had lipoatrophy; on average those with baseline lipoatrophy gained 0.96L of leg SAT compared with 1.23L gain for controls in the lowest decile (P = 0.16). At follow-up, 53% of HIV-infected participants had lipoatrophy. In multivariable models, discontinuation of stavudine appeared to produce little gain in leg SAT ( approximately 1.1%/year).

CONCLUSION

HIV-infected participants did not substantially recover SAT compared with controls, although both showed average gains. HIV-associated lipoatrophy persisted after 5 years of follow-up.

[Durability and tolerability of long-term nevirapine-based HAART]

Efficacy and tolerability of nevirapine-based HAART regimens were retrospectively evaluated. HIV-1-infected patients were included if they had been receiving a NVP-containing HAART regimen for at least 60 months, regardless of the reason for its initiation. A total of 82 patients were included in this study. The median follow-up time period was 96 months (range 64-120). At the time of starting NVP-based therapy, 31.7% (26 patients) were antiretroviral-naive, while 68.3% (56 patients) switched to an NVP-based strategy because of intolerance to the prior regimen, failure of a previous regimen or for simplification purposes. Coinfection with hepatitis B or C viruses was present in 26.8% of the patients (n 22). The most frequent nucleoside analogue backbone was zidovudine/lamivudine (52.4%) followed by stavudine/lamivudine (15.8%). A protease inhibitor was concomitantly administered in 2.4% of cases. To investigate the tolerability, we report the results separately on the basis of the presence/absence of HBV and/or HCV coinfection. Coinfected patients displayed significantly higher baseline liver enzymes than non-coinfected patients. Nevertheless, ALT levels showed a constant decrease over time in coinfected patients. Overall, median triglycerides, HDL and total cholesterol values tended to be lower in coinfected patients than in the remaining subjects. In particular, there was a significant decrease in triglyceride values in both groups and, concomitantly, a slight increase in total cholesterol. On the other hand, HDL cholesterol demonstrated a progressive increase. Finally, no change was found in glucose plasma levels, which always remained within normal ranges. In conclusion, no long-term toxicities associated with the use of nevirapine beyond five years were documented in our cohort of patients, even in coinfected patients. Long-term exposure to nevirapine was associated with optimal HIV suppression and favourable lipidic and glucidic profiles.

Stavudine-loaded mannosylated liposomes: in-vitro anti-HIV-I activity, tissue distribution and pharmacokinetics

Cells of the mononuclear phagocyte system (MPS) are important hosts for human immunodeficiency virus (HIV). Lectin receptors, which act as molecular targets for sugar molecules, are found on the surface of these cells of the MPS. Stavudine-loaded mannosylated liposomal formulations were developed for targeting to HIV-infected cells. The mannose-binding protein concanavalin A was employed as model system for the determination of in-vitro ligand-binding capacity. Antiretroviral activity was determined using MT-2 cell line. Haematological changes, tissue distribution and pharmacokinetic studies of free, liposomal and mannosylated liposomal drug were performed following a bolus intravenous injection in Sprague-Dawley rats. The entrapment efficiency of mannosylated liposomes was found to be 47.H ± 1.57%. Protein-carbohydrate interaction has been utilized for the effective delivery of mannosylated formulations. Cellular drug uptake was maximal when mannosylated liposomes were used. MT2 cells treated continuously with uncoated liposomal formulation had p24 levels 8–12 times lower than the level of free drug solution. Further, the mannosylated liposomes have shown p24 levels that were 14–20 and 1.42.3 times lower than the level of free drug and uncoated liposomal formulation treatment, respectively. Similar results were observed when infected MT2 cells were treated overnight. Stavudine, either given plain or incorporated in liposomes, led to development of anaemia and leucocytopenia while mannosylated liposomes overcame these drawbacks. These systems maintained a significant level of stavudine in the liver, spleen and lungs up to 12 h and had greater systemic clearance as compared with free drug or the uncoated liposomal formulation. Mannosylated liposomes have shown potential for the site-specific and ligand-directed delivery systems with desired therapeutics and better pharmacological activity.

Synthesis and in vitro human skin penetration of oligo- and polymeric ethylene glycol carbonates of zidovudine and stavudine

In continuation of studies focusing on the transdermal delivery of antiretroviral (ARV) drugs, the skin permeation ability of synthesized homologous series of both oligomeric and polymeric ethylene glycol (PEG) carbonates of zidovudine (3'-azido-3'-deoxythymidine, AZT, CAS 30516-87-1) and stavudine (2',3'-dideoxy-2',3'-didehydrothymine, d4T, CAS 3056-17-5) was evaluated in vitro through excised human skin in phosphate buffered solution (PBS) (0.01 M, pH 7.4) at 37 degrees C by using Franz cell diffusion methodology. The results revealed that all the derivatives permeated the skin regardless of the series. However, the derivative having three ethylene glycol repeating units was the most effective permeant in each series. The skin permeation rates of zidovudine and stavudine were enhanced by factors in the 2-4, and 1-3 range through these carbonates, respectively.

Steady-state nevirapine, lamivudine and stavudine levels in Malawian HIV-infected children on antiretroviral therapy using split Triomune 30 tablets

BACKGROUND

Children remain under-represented in national antiretroviral treatment (ART) programmes in settings with limited resources and high HIV prevalence. In Malawi, an increasing number of HIV-infected children have been started on ART with split tablets of an adult fixed-dose combination drug in the past few years. In 2006, the national paediatric ART regime was changed from Triomune 40 (T40) to Triomune 30 (T30).

METHODS

This was a cross-sectional study conducted at the paediatric ART clinic in Blantyre (Malawi) from September 2006 to July 2007. Children taking T30 for > 6 weeks from each dosing weight band (<5, 5-<8, 8-<12, 12-<14, 14-<19, 19-<26, 26-<30 and > or = 30 kg) were recruited. Plasma drug concentration, CD4+ T-cell count and HIV viral load were measured.

RESULTS

A total of 74 children were analysed. The median nevirapine (NVP) concentration was 7.35 mg/l. A therapeutic NVP plasma level > 3 mg/l was found in 62 (87.8%) children. A subtherapeutic NVP level (< 3 mg/l) occurred significantly more often in children treated with T30 doses between one-quarter tablet once daily and one-half tablet twice daily (P=0.035). Median prescribed NVP dose was 342 mg/m(2)/day, but 13 (17.6%) children received a dose below the recommended dose of 300 mg/m(2)/day. Compared with a historical control, the median prescribed NVP dose was increased (from 243 to 342 mg/m(2)/day).

CONCLUSIONS

Our findings indicate that with the Malawian T30-based ART regime, the majority (87.8%) of children in the study group achieved a therapeutic NVP level. However, treatment remains suboptimal especially for young children receiving T30 dosages less than or equal to one-half tablets twice daily and child appropriate formulations are warranted.

Virologic and immunologic outcomes in HIV-infected Cambodian children after 18 months of highly active antiretroviral therapy (HAART)

This observational cohort study was conducted among HIV-infected, antiretroviral therapy (ART) naive children in Phnom Penh, Cambodia, to evaluate the feasibility and efficacy of highly active antiretroviral therapy (HAART) delivered using a modified directly observed therapy (MDOT) protocol. From August 2004 to March 2006, 26 children were enrolled and started on a first-line HAART regimen, which was continued for 18 months. The study included a directly observed therapy phase (months 1-3) and a medication self-administration phase (months 4-18). CD4 percentage (CD4%) and HIV-1 RNA plasma viral load (PVL) were measured at baseline and at months 6, 12, and 18. At baseline, the median age was 5.5 years (range: 13 months-12 years), the median CD4% was 4, and the median PVL was 7.5x10(5) copies/ml. At 18 months, 23 (88%) children were alive and participating in the study. Of these children, 20 (87%) had a PVL <400 copies/ml and 12 (52%) had PVL < 50 copies/ml. The median CD4% increased to 23, while the median change in height-for-weight z-score was 0.64. Genotypic resistance typing in 2 children with PVL > 400 copies/ml at 18 months demonstrated mutations associated with resistance to lamivudine (M184V) and non-nucleoside reverse transcriptase inhibitors (Y181C and G190A). The virologic and immunologic outcomes achieved in this study compare favorably with those reported by other pediatric HIV treatment programs worldwide. The study results suggest that MDOT may be effective for HAART administration in limited-resource settings like Cambodia.

Rates of virological failure in patients treated in a home-based versus a facility-based HIV-care model in Jinja, southeast Uganda: a cluster-randomised equivalence trial

BACKGROUND

Identification of new ways to increase access to antiretroviral therapy in Africa is an urgent priority. We assessed whether home-based HIV care was as effective as was facility-based care.

METHODS

We undertook a cluster-randomised equivalence trial in Jinja, Uganda. 44 geographical areas in nine strata, defined according to ratio of urban and rural participants and distance from the clinic, were randomised to home-based or facility-based care by drawing sealed cards from a box. The trial was integrated into normal service delivery. All patients with WHO stage IV or late stage III disease or CD4-cell counts fewer than 200 cells per microL who started antiretroviral therapy between Feb 15, 2005, and Dec 19, 2006, were eligible, apart from those living on islands. Follow-up continued until Jan 31, 2009. The primary endpoint was virological failure, defined as RNA more than 500 copies per mL after 6 months of treatment. The margin of equivalence was 9% (equivalence limits 0.69-1.45). Analyses were by intention to treat and adjusted for baseline CD4-cell count and study stratum. This trial is registered at http://isrctn.org, number ISRCTN 17184129.

FINDINGS

859 patients (22 clusters) were randomly assigned to home and 594 (22 clusters) to facility care. During the first year, 93 (11%) receiving home care and 66 (11%) receiving facility care died, 29 (3%) receiving home and 36 (6%) receiving facility care withdrew, and 8 (1%) receiving home and 9 (2%) receiving facility care were lost to follow-up. 117 of 729 (16%) in home care had virological failure versus 80 of 483 (17%) in facility care: rates per 100 person-years were 8.19 (95% CI 6.84-9.82) for home and 8.67 (6.96-10.79) for facility care (rate ratio [RR] 1.04, 0.78-1.40; equivalence shown). Two patients from each group were immediately lost to follow-up. Mortality rates were similar between groups (0.95 [0.71-1.28]). 97 of 857 (11%) patients in home and 75 of 592 (13%) in facility care were admitted at least once (0.91, 0.64-1.28).

INTERPRETATION

This home-based HIV-care strategy is as effective as is a clinic-based strategy, and therefore could enable improved and equitable access to HIV treatment, especially in areas with poor infrastructure and access to clinic care.

[Therapeutic effect and safety evaluation on 6-year highly active antiretroviral therapy for Chinese HIV-1 infected patients]

OBJECTIVE

To evaluate the long-term efficacy and safety of nevirapine (NVP)-based regimens for HIV-infected Chinese patients in routine clinical practice.

METHODS

From October 2002 to May 2004, 57 HIV-1-infected patients commenced highly active antiretroviral therapy (HAART), and were followed to December 2008. They originally received 2 nucleoside reverse transcriptase inhibitors (NRTIs) and nevirapine. HIV RNA levels, T lymphocyte subsets and safety were assessed. Blood routine test and main laboratory parameter changes were traced. If apparent side effects or virological failure appeared we would, if necessary, terminate the therapy or change the regimen.

RESULTS

Of the 57 subjects, 34 were followed-up for more than 4 years. After 5-6 years, 63.3% of the subjects (19/30) had HIV RNA levels<50 copies/microL, and the median increase in CD4(+) cell count from the baseline was 329 cells/microL. The mean decrease in CD8(+) cell count was 128 cells/microL. At the same time, the CD4(+) CD45RA+CD62L cell count and CD4(+)CD45RO(+) cell gradually increased, and the counts of CD8(+)CD38(+) cell declined gradually. These changes are apparent 2 years after HAART. The increase rate slowed down after 2 years. But they did not recover completely as well as healthy people at year 6. About 56% (32/57) of HIV-infected patients developed various drug-related side effects. The most common was gastrointestinal side effect, followed nervous disorder, baldness, and rashes, mostly happened in 6 months. Gamma-GT increased occurred in 29.8% of patients (17/57), and serum cholesterol and triglyceride elevated in 26.3% of the patients (15/57). Six patients developed lipodystrophy, mainly in female patients, and 25 patients showed abnormal blood picture and liver function, renal function changes and amylase elevation. Grade 3-4 adverse events occurred in 3 cases (2 peripheral neuropathy, and 1 suspected lactic acidosis). One subject experienced grade 3 rashes.

CONCLUSION

Antiretroviral therapy with NVP-based regimens is safe and effective by suppressing HIV viremia and producing continued CD4 cell increases in subjects with HIV or AIDS for 6 years.

Benefits and risks of stavudine therapy for HIV-associated neurologic complications in Uganda

BACKGROUND

The frequency of HIV dementia in a recent study of HIV+ individuals at the Infectious Disease Institute in Kampala, Uganda, was 31%. Coformulated generic drugs, which include stavudine, are the most common regimens to treat HIV infection in Uganda and many other parts of Africa.

OBJECTIVE

To evaluate the benefits and risks of stavudine-based highly active antiretroviral therapy (HAART) for HIV-associated cognitive impairment and distal sensory neuropathy. The study compared neuropsychological performance changes in HIV+ individuals initiating HAART for 6 months and HIV- individuals receiving no treatment for 6 months. The risk of antiretroviral toxic neuropathy as a result of the initiation of stavudine-based HAART was also examined.

METHODS

At baseline, 102 HIV+ individuals in Uganda received neurologic, neuropsychological, and functional assessments; began HAART; and were followed up for 6 months. Twenty-five HIV- individuals received identical clinical assessments and were followed up for 6 months.

RESULTS

In HIV+ individuals, there was improvement in verbal memory, motor and psychomotor speed, executive thinking, and verbal fluency. After adjusting for differences in sex, HIV+ individuals demonstrated significant improvement in the Color Trails 2 test (p = 0.025) compared with HIV- individuals. Symptoms of neuropathy developed in 38% of previously asymptomatic HIV+ patients after initiation of the stavudine-based HAART.

CONCLUSIONS

After the initiation of highly active antiretroviral therapy (HAART) including stavudine, HIV+ individuals with cognitive impairment improve significantly as demonstrated by improved performance on a test of executive function. However, peripheral neurotoxicity occurred in 30 patients, presumably because of stavudine-based HAART, suggesting the need for less toxic therapy.

Demographic, socio-economic, behavioral and clinical factors predicting virologic failure with generic fixed-dose combination antiretroviral therapy before universal health insurance coverage in northern Thailand

We conducted a 2-year prospective cohort study to investigate multiple aspects of factors predicting the outcome of fixed-dose combination antiretroviral (ARV) therapy with lamivudine, stavudine, and nevirapine (GPOvir) at a government referral hospital in northern Thailand. At 6 and 24 months after the initiation of GPOvir, viral load (VL) was measured to determine virologic failure (>400 RNA copies/ml) and demographic, socio-economic, behavioral and clinical data were collected. From 10 April 2002 to 31 January 2004, 409 patients participated in this study: 64/364 (17.0%) at 6 months and 55/345 (15%) at 24 months virologically failed treatment. On univariate analysis, besides ARV experience [odds ratio (OR), 3.08, 95% confidence interval (CI), 1.71 -5.57] and the frequency of delayed doses (OR, 2.97; 95% CI, 1.47-6.00), we identified one socioeconomic factor significantly associated with virologic failure: "not having child" (OR, 1.85; 95% CI, 1.03 - 3.34). Although the association with "not having child" became marginal on multivariate analysis, results of in-depth interviews and group discussions indicated that having a child was a strong motivating factor for good treatment compliance. We suggest that patients without children may need more attention. Further investigation of socio-economic factors is warranted.

Steady-state pharmacokinetic comparison of generic and branded formulations of stavudine, lamivudine and nevirapine in HIV-infected Ugandan adults

BACKGROUND

We aimed to compare the steady-state pharmacokinetic parameters and tolerability of Triomune 40 (stavudine 40 mg, lamivudine 150 mg and nevirapine 200 mg) and branded formulations of these drugs in HIV-infected Ugandans.

METHODS

This includes a randomized, open-label, cross-over study of HIV-infected patients stable on therapy for 1 month. Patients were randomized to generic or branded formulation. Plasma pharmacokinetics were assessed after 1 month. The following day, alternate formulation was administered, and 1 month later, drug pharmacokinetics were re-assessed. Plasma pharmacokinetics were determined using HPLC-UV detection. Similarity between steady-state pharmacokinetic parameters was assessed using the US Food and Drug Administration standards for bioequivalency testing. Tolerability was assessed using questionnaires.

RESULTS

Sixteen (10 females) patients completed the study. Median (IQR) age, weight and CD4 count were 37 (33.7-40) years, 65 (63.4-66) kg and 292 (220.7-344.5) cells/mm(3), respectively. All patients received co-trimoxazole. The geometric mean ratio (90% CI) for stavudine, lamivudine and nevirapine was 0.92 (0.78-1.08), 1.11 (0.95-1.30) and 0.84 (0.64-1.11), respectively, for C(max), and 0.83 (0.70-0.97), 1.06 (0.94-1.20) and 0.88 (0.71-1.10), respectively, for AUC. Stavudine plasma concentrations were significantly lower for the generic formulation. Pharmacokinetic parameter inter-individual variability ranged from 29% to 99%. There were no differences in tolerability for the two formulations.

CONCLUSIONS

Pharmacokinetic profiles of generic and branded drugs were similar. Differences particularly with regard to stavudine were demonstrated. Surveillance of the quality of generic antiretroviral drugs in the target populations is needed. Capacity building for pharmacokinetic research in resource-limited settings is a priority.

[Evaluation of antiretroviral therapy in HIV-infected adults in the Department of Haematology, University Hospital of Brazzavllle, Congo]

A retrospective study was conducted during 32 months; from 1 May 2003 to 30 December 2005 in haematology department. The objective of the study was to assess the effectiveness of the anti retroviral therapy 157 patients receiving antiretroviral treatment for at least a twelve month-period and presenting AIDS symptoms based on revised CDC criteria were included. The average number of initial T4 lymphocytes is 133/mm3 (extremes 1 and 385) and the initial plasmatic average viral load, quantified in 96 patients is 214,000 copies (extreme 30,000 et 999,000) The initial antiretroviral combinations were as follows: ZDV or D4T + LMV + NVP (59.2%); ZDV or D4T + LMV + EFV (28.7%), ZDV or D4T + LMV + IDNV (8.9%); ZDV or D4T + DDI + NVP (3.2%). The results of the study are: observance rate during the first 12 months (84%), antiretroviral therapy taken irregularly (10.8%), early submission of therapy (5.2%), weight gain after 24 months: +18 kgs, clinical response globally positive. The immune response is characterised by an average increase of 353/mm3 of CD4 after 24 months. Among 96 patients tested, the plasmatic viral load was undetectable in 71% of cases after a 12 month-follow up. Mild adverse drug effects have been noticed, represented by cutaneous and nervous toxicity anaemia and digestive disorders due to indinavir These therapeutic results confirm the importance of the antiretroviral therapy in the improvement of the quality of life of HIV/AIDS patients but a concern remains on the possible drug resistance still not documented.

Severe hyperlactataemia complicating stavudine first-line antiretroviral therapy in South Africa

BACKGROUND

In the public sector antiretroviral therapy (ART) programme in South Africa the standardized first-line regimen includes stavudine (d4T). Severe symptomatic hyperlactataemia (SHL) is a potentially life-threatening complication of d4T.

METHODS

GF Jooste Hospital is a referral centre for six ART clinics. We retrospectively reviewed cases referred with lactate levels > or =5 mmol/l that were attributed to nucleoside reverse transcriptase inhibitors from August 2003 to November 2005. We calculated cumulative ART exposure in patients attending these clinics to derive a referral rate.

RESULTS

In total, 75 patients were referred with severe SHL (71 female). All had been on d4T and on ART for a median of 10 months. The referral rate for severe SHL was 17.5 cases per 1,000 patient-years. In 53 patients (71%), lactic acidosis (standard bicarbonate [SHCO3] <20 mmol/l) was confirmed, resulting in a referral rate of 12.3 cases per 1,000 patient-years. Twelve patients (16%) died during acute admission (< or =30 days). SHCO3 <15 mmol/l and pH < 7.2 were the only factors associated with acute mortality (odds ratio [OR] 22.5, 95% confidence interval [CI] 2.8-1,045.7 and OR 13.9, 95% CI 2.7-86.9, respectively). A total of 30 less severe cases were rechallenged with zidovudine without recurrence of SHL.

CONCLUSIONS

This study confirms a high incidence of severe SHL in Africa, which has been shown in previous studies. Rechallenge with zidovudine in less severe cases was found to be safe.