Improvements in lipoatrophy, mitochondrial DNA levels and fat apoptosis after replacing stavudine with abacavir or zidovudine.

OBJECTIVE: To determine if stavudine (alpha4T)-associated mitochondrial toxicity could be reversed by substitution with another nucleoside reverse transcriptase inhibitor. As apoptosis and dysfunction of electron transport chain (ETC) activities may underlie mitochondrial toxicity, these parameters were also evaluated. DESIGN: The 16 participants (on d4T for >3 years; with lipoatrophy and/or hyperlactatemia) substituted abacavir or zidovudine for stavudine in their antiretroviral regimen. Key parameters including dual-energy X-ray absorptiometry (DEXA) scans, fat apoptosis, mitochondrial DNA (mtDNA) content in peripheral blood mononuclear cells (PBMC), skeletal muscle and fat, as well as skeletal muscle mitochondrial ETC activities were evaluated at study entry and at 48 weeks after the substitution. METHODS: Quantitative PCR was used to evaluate mtDNA levels and the presence of deletions/rearrangements; CLIA-validated methods for ETC activities; terminal deoxynucleotidyl transferase dUTP-digoxigenin nick-end labeling assays to evaluate adipocyte apoptosis; and DEXA scans to measure changes in body fat. RESULTS: MtDNA was depleted at study entry in muscle, adipose tissue and PBMC but levels rebounded with respective mean increases of 141%, 146%, and 369% at week 48. Corresponding fat improvements were noted with DEXA increases of 21%, 11%, and 16% in arm, leg, and trunk, respectively. Quantitative adipocyte apoptosis were significantly increased at baseline (P < 0.01 versus HIV-negative controls), with a significant reduction at week 48 (P < 0.05 versus baseline). Mean values for seven mitochondrial enzyme activities assays at entry indicated substantial loss of function (48% to 85% of controls) with significant improvement of complex I activity by week 48. CONCLUSIONS: Substitution of stavudine with abacavir or zidovudine improves mitochondrial indices and fat apoptosis in the setting of lipoatrophy.

Lack of recurrence of hyperlactatemia in HIV-infected patients switched from stavudine to abacavir or zidovudine.

Stavudine (d4T) has been observed in clinical trials and cohort studies to be more often implicated in cases of hyperlactatemia than other nucleoside reverse transcriptase inhibitors, possibly because of its relatively greater propensity to induce mitochondrial toxicity. The ESS40010 study was a 48-week, open-label, switch study that assessed changes in serum lactate levels and signs/symptoms of hyperlactatemia after substitution of abacavir (n = 86) or zidovudine (n = 32) for d4T in 118 virologically suppressed HIV-infected patients (HIV-1 RNA <400 copies/mL) who had developed serum lactate concentrations > or =2.2 mmol/L (n = 16) or had remained normolactatemic (n = 102) after receiving > or =6 months of d4T-based treatment. Median serum lactate decreased significantly below baseline at week 24 (-0.15 mmol/L, P = 0.0002) and week 48 (-0.15 mmol/L, P = 0.0015). In 10 hyperlactatemic patients in whom d4T was discontinued, serum HIV-1 RNA levels rebounded over the ensuing 31 days, but virologic suppression (HIV-1 RNA <400 copies/mL) was regained when treatment using abacavir or zidovudine was subsequently instituted. In the group with elevated lactate at baseline, symptoms of hyperlactatemia improved in 8% to 23% of patients, did not change in 69%, and worsened in 8%. Serum transaminases, which had been elevated while patients received d4T, normalized after d4T discontinuation and remained in the normal range after the switch to abacavir or zidovudine. Overall, in patients with d4T-associated hyperlactatemia, stopping d4T results in normalization of lactate and a rebound in viral load; restarting treatment using abacavir or zidovudine subsequently maintains normal lactate levels and rapidly leads to a return of virologic suppression.

Improvement in lipoatrophy associated with highly active antiretroviral therapy in human immunodeficiency virus-infected patients switched from stavudine to abacavir or zidovudine: the results of the TARHEEL study.

Stavudine use is a contributing factor for lipoatrophy, whereas use of abacavir or zidovudine is less likely to cause this complication. The TARHEEL study was a 48-week, open-label study that assessed changes in lipoatrophy after abacavir (86 patients [73%]) or zidovudine (32 patients [27%]), 300 mg twice daily, was substituted for stavudine for 118 human immunodeficiency virus (HIV)-infected patients (HIV type 1 RNA level, <400 copies/mL) with virological suppression who had developed lipoatrophy after > or =6 months of stavudine-based treatment. At week 48, full-body dual-energy x-ray absorptiometry demonstrated a median increase in arm fat of 35%, leg fat of 12%, and trunk fat of 18%, compared with the baseline level. These improvements coincided with fat gain in lipoatrophic areas that was documented by computerized tomography. Results of a "body image" questionnaire showed that a substantial percentage of patients reported some or a lot of fat gain in the arms (22%), legs (18%), buttocks (19%), and face (27%). HIV suppression was maintained over the study period. In conclusion, replacing stavudine with abacavir or zidovudine resulted in improvement in stavudine-induced lipoatrophy.

Compact quadruple therapy with the lamivudine/zidovudine combination tablet plus abacavir and efavirenz, followed by the lamivudine/zidovudine/abacavir triple nucleoside tablet plus efavirenz in treatment-naïve HIV-infected adults.

PURPOSE: To assess efficacy, safety, and adherence with compact quadruple therapy comprising one lamivudine 150-mg/zidovudine 300-mg tablet (COM) twice daily + one abacavir (ABC) 300-mg tablet twice daily + three efavirenz (EFV) 200-mg capsules at bedtime for 24 weeks, followed by one lamivudine 150-mg/zidovudine 300-mg/ABC 300-mg triple nucleoside tablet (TZV) twice daily + three EFV 200-mg capsules at bedtime for 24 weeks. METHOD: A pilot 48-week, prospective, open-label trial in which 38 antiretroviral-naïve HIV-infected adults (baseline median HIV-1 RNA 5.1 log(10) copies/mL, CD4+ cell count 285/microL) received the above treatment and were monitored regularly with respect to plasma HIV-1 RNA levels, CD4+ cell counts, T-cell receptor excision circles (TRECs), adherence, and adverse events. RESULTS: At Week 48, intent-to-treat, switch-included analysis showed plasma HIV-1 RNA levels <400 copies/mL in 100% (29/29) of patients and <50 copies/mL in 93% (27/29); 59% of patients who achieved <50 copies/mL had <3 copies/mL (16/27). Similar virologic suppression was observed in patients with baseline HIV-1 RNA above or below 100000 copies/mL. HIV-1 RNA and CD4+ cell counts changed from baseline by a median of -3.4 log(10) copies/mL and +172 cells/microL, respectively. One virologic failure occurred at Week 16. Median TRECs/100000 peripheral blood lymphocytes increased 6-fold between baseline and Week 48. Median adherence rates were consistently 100% by self-report and 94% by pill count. Grade 2-4 treatment-related adverse events included dreams (16%), nausea (13%), decreased white cells (8%), dizziness (8%), sleep disorders (8%), and malaise and fatigue (8%). A suspected ABC hypersensitivity reaction occurred in 8% (3/38) of patients. CONCLUSION: COM/ABC/EFV or TZV/EFV produced potent, durable virologic suppression and immunologic benefits, was associated with high adherence rates, and was generally well tolerated.

Response to lamivudine-zidovudine plus abacavir twice daily in antiretroviral-naive, incarcerated patients with HIV infection taking directly observed treatment.

Prison inmates with human immunodeficiency virus (HIV) infection can be difficult to treat because of the complexity and intrusiveness of many combination antiretroviral therapy regimens. NZTA4007, a 24-week open-label, single-arm clinical trial involving 108 antiretroviral therapy-naive, incarcerated, HIV-infected persons, was conducted to evaluate a compact regimen (4 tablets per day) consisting of 1 lamivudine-zidovudine (150 mg/300 mg) combination tablet (COM) and one 300-mg abacavir tablet administered twice daily under directly observed treatment conditions. In the intent-to-treat observed analysis, the plasma HIV type 1 (HIV-1) RNA level remained at < or =400 copies/mL in 85% of the patients and at < 50 copies/mL in 75% of the patients. Median change from baseline was -2.41 log(10) copies/mL for the HIV-1 RNA level and +111 cells/mm(3) for the CD4 cell count. The overall adherence to prescribed doses was 94% for patients who remained enrolled in the study. COM-abacavir given twice daily was generally well tolerated, and adverse events prompted only 4 patients to withdraw from the study.