Cheaper counterparts of the original HIV drugs may be less effective, say experts in the Annals of Internal Medicine.
Generic drugs, or generics, also called generics, are substitutes for the original drug, containing the same active substance. They are cheaper because their producers are not monopolists, and they do not have to spend huge sums on research. Manufacturers of generic drugs can start producing them after the expiry of the patent protection period. Their use allows for a significant reduction in the costs of pharmacotherapy – both in the scale of the state and the individual patient.
In order for generics to be marketed, they must contain the same amount of the active substance, have the same form, bioavailability and the same pharmacological effect. They may contain other excipients than the original drug, provided that they do not change the properties of the drug and do not affect its effectiveness.
Data published by US specialists from Massachusetts General Hospital suggest that generic drugs used in HIV infection may be slightly less effective. Patients then have to take three pills a day instead of one, which increases the risk of missed doses.
According to the authors of the publication, the extensive use of generic drugs against HIV may result in more cases of therapy failure, and the reduced effectiveness of treatment will translate into an average reduction in survival time by 4,4 months. At the same time, savings on one patient will amount to 42 dollars throughout his life.
The currently recommended treatment for newly diagnosed patients is based on a single pill (Atripla) administered once daily. This pill contains the three antiviral drugs tenofovir (Viread), emtricitabine (Emtriva) and efavirenz (Sustiva).
A generic drug with a mechanism of action similar to emtricitabine became available in January 2012, a generic form of efavirenz is expected in the near future. Patients will be able to take these two cheaper drugs along with the original tenofovir.
As noted by one of the authors, Dr. Rochelle Walensky, the cheaper combination may be effective in disciplined patients who follow the indications of doctors, but skipping a dose may lead to treatment failure (PAP).
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