Article

The frequency and reasons for antiretroviral switching with specific antiretroviral associations: the SWITCH study.

St. Stephen's Centre, Chelsea and Westminster Hospital Trust, United Kingdom.
Antiviral research (Impact Factor: 3.61). 03/2010; 86(2):227-9. DOI: 10.1016/j.antiviral.2010.03.001
Source: PubMed

ABSTRACT We investigated the reasons for switching antiretroviral regimens, an issue rarely addressed in cohort studies.
An observed toxicity switch rate (OTSR) was calculated by Poisson regression using the number of days individuals received each individual antiretroviral drug.
Of 3333 individuals receiving HAART, a total of 14% of regimens were switched, the majority occurring after 6 months of therapy. Toxicity was the major reason for switching (61%) and there were no major statistically significant differences in OTSR between the protease inhibitor (OTSR 26.4, 95% CI 18.3-37) and non-nucleoside reverse transcriptase inhibitor (OTSR 22.2, 95% CI 13.6-34.4) based regimes. For individual antiretrovirals, stavudine and zidovudine had significantly higher "switch" scores than all other drugs.
There were no differences between the major HAART classes in OTSR. We suggest that newer antiretrovirals will require differentiation in terms of longer-term toxicity, as this is the major reason for switching.

0 Bookmarks
 · 
76 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Modifications to combination antiretroviral drug therapy (CART) regimens can occur for a number of reasons, including adverse drug effects. We investigated the frequency of and reasons for antiretroviral drug modifications (ADM) during the first 3 years after initiation of CART, in a closed cohort of CART-naïve adult patients who started treatment in the period 1998-2007 in Croatia. Material and Methods We calculated differential toxicity rates by the Poisson method. In multivariable analysis, we used a discrete-time regression model for repeated events for the outcome of modification due to drug toxicity. Results Of 321 patients who started CART, median age was 40 years, 19% were women, baseline CD4 was <200 cells/mm3 in 71%, and viral load was ≥100 000 copies/mL in 69%. Overall, 220 (68.5%) patients had an ADM; 124 (56%) of these had ≥1 ADM for toxicity reasons. Only 12.7% of individuals starting CART in the period 1998-2002 and 39.4% in the period 2003-2007 remained on the same regimen after 3 years. The following toxicities caused ADM most often: lipoatrophy (22%), gastrointestinal symptoms (20%), and neuropathy (18%). Only 5% of drug changes were due to virologic failure. Female sex (hazard ratio [HR], 2.42 95%; confidence intervals, 1.39-4.24) and older age (HR, 1.42 per every 10 years) were associated with toxicity-related ADM in the first 3 months of a particular CART regimen, but after 3 months of CART they were not. Conclusions Less toxic and better-tolerated HIV treatment options should be available and used more frequently in Croatia.
    Medical science monitor: international medical journal of experimental and clinical research 01/2013; 19:483-492. · 1.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background. Delays detecting treatment failure and switching to second-line combination antiretroviral therapy (cART) are often observed in human immunodeficiency virus (HIV)–infected children of low-middleincome countries (LMIC). Methods. An observational study included HIV-infected children attending the Beira Central Hospital (Mozambique) and the Nsambya Hospital, Home Care Department (Uganda) evaluated clinical and immunological failure according to World Health Organization (WHO) 2006 guidelines. Baseline predictors for cART failure and for drug substitution were explored in unadjusted and adjusted Cox proportional hazard models. Results. Two hundred eighteen of 740 children with at least 24 weeks follow-up experienced treatment failure (29%; 95% confidence interval [CI] 26–33), with crude incidence of 20.0 events per 100 person-years (95% CI 17.5–22.9). Having tuberculosis co-infection orWHO stage 4, or starting a nontriple cART significantly increased risk of failure. Two hundred two of 769 (26.3%) children receiving cART substituted drug(s), with crude incidence of 15.4 events per 100 person-years (95% CI 13.4–17.7). Drug toxicity (18.3%), drug availability (17.3%), and tuberculosis drugs interaction (52, 25.7%) were main reported reasons, while only 9 (4%) patients switched cART for clinical or immunological failure. Children starting lamivudine-zidovudine-nevirapine or lamivudine-stavudineefavirenz or lamivudine-zidovudine-efavirenz were more likely to have substitute drugs. Increased substitution was found in children with mild immunosuppression and tuberculosis co-infection at cART initiation as well as poor adherence before drug substitution. Conclusions. Considerable delay in switching to second-line cART may occur despite an observed high rate of failure. Factors including WHO clinical stage and tuberculosis co-infection should be evaluated before starting cART. Toxicity and drug adherence should be monitored to minimize drug substitution in LMIC.
    Journal of the Pediatric Infectious Diseases Society. 05/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Limited antiretroviral treatment regimens in resource-limited settings require long-term sustainability of patients on the few available options. We evaluated the incidence and predictors of combined antiretroviral treatment (cART) modifications, in an outpatient cohort of 955 patients who initiated cART between January 2009 and January 2011 in western Kenya. cART modification was defined as either first time single drug substitution or switch. Incidence rates were determined by Poisson regression and risk factor analysis assessed using multivariate Cox regression modeling. Over a median follow-up period of 10.7 months, 178 (18.7%) patients modified regimens (incidence rate (IR); 18.6 per 100 person years [95% CI: 16.2-21.8]). Toxicity was the most common cited reason (66.3%). In adjusted multivariate Cox piecewise regression model, WHO disease stage III/IV (aHR; 1.82, 95%CI: 1.25-2.66), stavudine (d4T) use (aHR; 2.21 95%CI: 1.49-3.30) and increase in age (aHR; 1.02, 95%CI: 1.0-1.04) were associated with increased risk of treatment modification within the first year post-cART. Zidovudine (AZT) and tenofovir (TDF) use had a reduced risk for modification (aHR; 0.60 95%CI: 0.38-0.96 and aHR; 0.51 95%CI: 0.29-0.91 respectively). Beyond one year of treatment, d4T use (aHR; 2.75, 95% CI: 1.25-6.05), baseline CD4 counts ≤350 cells/mm3 (aHR; 2.45, 95%CI: 1.14-5.26), increase in age (aHR; 1.05 95%CI: 1.02-1.07) and high baseline weight >60kg aHR; 2.69 95% CI: 1.58-4.59) were associated with risk of cART modification. Early treatment initiation at higher CD4 counts and avoiding d4T use may reduce treatment modification and subsequently improve sustainability of patients on the available limited options.
    PLoS ONE 04/2014; 9(4):e93106. · 3.53 Impact Factor