Profiling the risk factors of lactic acidosis in HIV positive adult patients on antiretroviral treatment in South Africa in the public sector
Date
2012-06-20
Authors
Padayachee, Neelaveni
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Abstract
Background: According to the 2010 edition of the UNAIDS Report on the global AIDS epidemic, an estimated 320 000 (20%) fewer people died of AIDS-related causes in South Africa in 2009 than in 2004 due to the increase in availability of anti-retroviral medicines.(2) With this positive trend, the mindset should be shifted towards reducing adverse effects of ART. The need for permanent ART treatment and the significant increase in life expectancy have led to the observation of new, frequent, and sometimes severe drug-related adverse effects.(4) One of the most challenging and potentially dangerous side-effects is hyperlactataemia (Hlac) that may evolve to lactic acidosis (LA)(5) ART–associated Hlac may be asymptomatic, or symptomatic which in the extreme case can progress to life threatening acidosis. The latter, i.e. lactic acidosis is a fairly frequent and often misdiagnosed or under diagnosed and potentially fatal side effect of ARTs. (6)
Objectives: To explore the relationship between Hlac/LA and gender, weight, dosage CD4 and regimen alterations in HIV patients on ARTs and to compare the earlier regimens to the revised regimens as independent risk factors for Hlac and LA. Sample size would be based on the hypothesis that newer regimens would reduce the incidence of Hlac and LA.
Methods: A Retrospective study was conducted by reviewing 3 741 patient files from August 2004 to December 2007. This study was to assess the incidence and risk factors of Hlac/LA. Hlac was defined as a venous lactate measurement of ≥2.3mmol/L and LA was ≥5mmol/L. Immunological, virological, haemotological and biochemical results were recorded for all the patients. A second phase involved a Prospective study. Patients who were on treatment for >12 months were randomly selected from the queue at the clinic between the September 2008 and December 2009. Immunological, virological, haematological and biochemical information was recorded for all patients selected. Analysis involved descriptive statistics, comparison of means, frequency analysis and multivariate analysis.
Results: Two-hundred and thirty two patients were identified with elevated lactate levels in the retrospective study. The incidence was 6.2% in this population, with gastro-intestinal symptoms, peripheral neuropathy, abdominal tenderness, rash and upper respiratory tract infection being the significant symptoms. The major risk factor was a low CD4 count. The prospective study included 292 patients with 24.3% with Hlac/LA with peripheral neuropathy (p 0.209), gastrointestinal symptoms (nausea, vomiting) (p 0.148) and abdominal tenderness (p 0.214) were the most significant symptoms. In terms of the hypothesis that newer regimens would lower the incidence of elevated lactate levels by 50%, the observed incidence of 24.3% is no different from previously reported rates. This therefore shows that although regimen changes have been implemented the overall incidence of Hlac appears to be unchanged but the LA rate was found to be significantly lower than before, 6.8 cases per 1000 patient years vs ±19 cases per 1000 person years.(16) Gastro-intestinal symptoms but not peripheral
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neuropathy; with low CD4 count, weight loss and low weight on entry were the significant risk factors, which is most likely representative of advanced disease. Conclusions: Although newer regimens have been introduced, Hlac/LA still exist. Healthworkers need to be on high alert for Hlac/LA particularly if a patient enters into the ART program with a low CD4 count and a low weight
Description
M. Pharm., Faculty of Health Sciences, University of the Witwatersrand, 2011