No evidence of reduced efficacy or increased side effects when patients Cocktail with generics reports study
An analysis of 440 people who switched to generic antiretroviral drugs at an Italian clinic and a cohort of patients who remained on their brand name medication found no evidence that generic drugs were less effective or caused more side effects. Nicola Gianotti and colleagues report in an article recently published in magazine PLoS ONE.
In many high-income countries, health services are under increasing financial pressures. At the same time, patents on various antiretroviral drugs have expired and the more economical generic versions of the same drugs have been made available. Doctors and pharmacists should use generic drugs when possible because they generally work as well as brand name drugs, and the money saved can pay for other treatments and services. (For more information on generic drugs, click here).
Cocktail with generics
However, some people question the quality and effectiveness of generic drugs. Generic manufacturers should prove that their products have the same pharmacokinetic properties as the original formulation with comparable drug levels of active ingredients but are not required to conduct direct comparative clinical trials of generic and brand name drugs. In addition, small differences in the ingredients and in the non-active manufacturing processes of a drug can potentially have an impact on a minority of patients.
Previous studies on generic antiretrovirals have been conducted in low- or middle-income countries. In addition, only one previous study compared the results between brand-name and generic patients - observation cohort of about 15.000 Zambian patients at the beginning of HIV treatment, half received zidovudine brand and half generic zidovudine. There were no differences in mortality, weight gain or CD4 response, but the virological response was not assessed.
The generic cocktail has gone through a new scrutiny
Switching to generics in Italy
The study comes from a single clinic in Milan, Italy. Beginning in September of 2014, all patients who were stable on lamivudine (Epivir), zidovudine / lamivudine (Combivir) or efavirenz (Sustiva) were transferred to a generic version of the same drug.
The researchers compared results to this group with a cohort of patients followed at the same clinic that did not switch drugs. It is important to note that this control group not is composed of patients taking the same drugs (lamivudine, zidovudine / lamivudine or efavirenz). Those in the control group were taking Outros antiretroviral agents that were not available in generic formulations. However, the control group was well-matched in other respects, including demographics and previous treatment experience.
Among the 440 switchers and 440 non-switchers, three-quarters were men, most were in the late 1940s or 1950s, and the median time since HIV diagnosis was 19 years. All participants had an undetectable viral load. His median CD4 cell count was about 700, his lowest possible CD4 cell count was slightly more than 200 and more than one quarter had antibodies against hepatitis C.
As noted, there were differences in terms of drugs taken. Considering that 40% of the switches were taking dual therapy based on protease inhibitors, this was the case for only 8% of non-switches. Only 60% of the switches were taking triple therapy, compared to 92% of non-switches.
Search results for Coke with Generics
The researchers evaluated the results after an average of 15 months of follow-up. The main results were virological failure and discontinuation of treatment.
Regarding virological failure (confirmed viral load higher than 50 copies / ml), there were four cases in switches and ten in non-switches. Virological failure was therefore less common in those taking generic drugs and the difference was statistically significant.
In order to analyze the virological results in more detail, the researchers also analyzed viral blipes (single viral load measurements greater than 50 copies / ml) and time spent with residual viremia (a viral load below 50 copies / ml that remained detectable in the absence of real-time PCR, associated with a greater risk of subsequent virological failure). There were no statistically significant differences - viral blipes occurred in 32 switches and 33 non-switches; The time spent with residual viremia was 29% and 30%, respectively.
Treatment discontinuation (any change in drug regimen) occurred at 118 (27%) of the switches and 128 (29%) of the non-switches. In both groups, the main reasons for drug switching were side effects, simplifying treatment and drug interactions. The discontinuation rate of treatment is high, but comparable to other cohorts of Italian people living with HIV.
Due to significant differences in drug regimen between the two groups, the researchers also performed a sensitivity analysis that included only patients treated with standard triple therapy. Virological failure was less common in those moving to generics. Discontinuation of treatment also appeared to be less common, but the difference was not statistically significant.
"In this observational study, we compared patients switched to generic antiretrovirals with a corresponding population who continued to take brand name drugs and found no evidence of reduced efficacy or increased toxicity related to switching from brand-name antiretroviral drugs to generics," the authors write. In addition, their findings on virological failures suggest that "the virological potency of these generic formulations is at least as high as that of the patented drugs."
Translated by Claudio Souza the original No evidence of reduced efficacy or increased side effects when patients switch to generic drugs, comparison study finds written by Roger Pebody on 24 August 2017
reviewed by Mara Macedo