[Efficacy and safety of a reduced-dose of stavudine in HIV-infected patients under immunological and virological stable conditions]

Quality of life in individuals living with HIV/AIDS attending a public sector antiretroviral service in Cape Town, South Africa

BACKGROUND

Health related quality of life (HRQoL) is an important outcome helping to understand the impact of antiretroviral therapy (ART). We examined and compared the HRQoL in relation to ART status among HIV-infected patients in a public sector service in Cape Town, South Africa. In addition, we aimed to examine the relationship between ART status and HRQoL according to CD4 count strata.

METHODS

A cross sectional study sample of 903 HIV-infected patients who were categorized as not receiving ART (ART-naïve) or receiving first-line ART for > 6 months (ART). HRQoL outcomes were compared in the two groups. HRQoL was assessed using the EQ-5D (five domains) and Visual Analogue Scale (EQ-5D VAS).

RESULTS

Of the total sample, 435 were categorised as ART naïve (76% women) and 468 were on ART (78% women). There were no significant associations between groups for most of the EQ-5D domains, however ART-naïve experienced a significantly greater problem with mobility than the ART group. Being ART-naïve (adjusted odds ratio (aOR) 3.08 95% confidence interval (CI) 1.63- 7.89) and obese 2.78 (95% CI 1.24- 6.22) were identified as predictors for increased mobility problems in multivariate analysis. In addition, receiving ART (5.61 difference; 95% CI 2.50 - 8.72) and having some source of income (4.76; 95% CI 1.63 -7.89) were identified as predictors for a higher EQ-5D VAS score. When grouped according to CD4 count strata, there were no significant difference between groups for most of the EQ-5D domains, however the ART-naïve group indicated having significantly greater problems under the CD4 count of >500 cells/μL in the anxiety/depression domain (22.4% vs 8.8%, p = 0.018) and significantly lower EQ-5D VAS scores under the CD4 counts of ≤ 200 cells/μL (median 80 (IQR 60-90) vs 90 (IQR 80-100), p = 0.0003) and 201-350 cells/μL (median 80 (IQR 70-90) vs 90 (80-100), p = 0.0004) compared to ART group.

CONCLUSIONS

HRQoL (self-rated health state) was improved with ART use, including those with immunocompromised status, which may be relevant to the public sector ART program in South Africa.

Effectiveness and safety of 30 mg versus 40 mg stavudine regimens: a cohort study among HIV-infected adults initiating HAART in South Africa

BACKGROUND

As stavudine remains an important and widely prescribed drug in resource-limited settings, the effect of a reduced dose of stavudine (from 40 mg to 30 mg) on outcomes of highly active antiretroviral therapy (HAART) remains an important public health question.

METHODS

We analyzed prospectively collected data from the Themba Lethu Clinic in Johannesburg, South Africa. We assessed the relationship between stavudine dose and six- and/or 12-month outcomes of stavudine substitution, failure to suppress viral load to below 400 copies/ml, development of peripheral neuropathy, lipoatrophy and hyperlactatemia/lactic acidosis. Since individuals with a baseline weight of less than 60 kg were expected to have received the same dose of stavudine throughout the study period, analysis was restricted to individuals who weighed 60 kg or more at baseline. Data were analyzed using logistic regression.

RESULTS

Between 1 April 2004 and 30 September 2009, 3910 patients were initiated on antiretroviral therapy (ART) with a recorded stavudine dose and were included in the analysis. Of these, 2445 (62.5%) received a 40 mg stavudine dose while 1565 (37.5%) received 30 mg. In multivariate analysis, patients receiving a 40 mg dose were more likely to discontinue stavudine use (adjusted odds ratio, OR 1.71; 95% confidence limits, CI 1.13-2.57) than those receiving 30 mg by 12 months on ART. Additionally, patients receiving 40 mg doses of stavudine were more likely to report peripheral neuropathy (OR 3.12; 95% CI 1.86-5.25), lipoatrophy (OR 11.8; 95% CI 3.2-43.8) and hyperlactatemia/lactic acidosis (OR 8.37; 95% CI 3.83-18.29) in the same time period. Failure to suppress HIV viral load within 12 months of HAART initiation was somewhat more common among those given 40 mg doses (OR 1.62; 95% CI 0.88, 2.97) although this result lacked precision. Sensitivity analyses accounting for death and loss to follow up generally supported these estimates.

CONCLUSIONS

Lower stavudine dosage is associated with fewer reports of several stavudine-associated adverse events and also a lower risk of stavudine discontinuation within the first year on ART.

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.