Dr. Eugenia Negredo, physician at the HIV Unit and head of the research line on antiretrovirals' toxicity and new treatment strategies, attended last week the CROI (Conference on Retroviruses and Opportunistic Infections) in Boston, USA.
She is the first author of a poster that was presented on the results of VIHZOL, a study promoted by the Fight AIDS Foundation, in which the use of two different doses of zoledronic acid in the treatment of osteoporosis in HIV positive was compared.
Osteoporosis leads to a decrease of the amount of minerals in the bones, which become brittle and susceptible to fracture. More and more people with HIV require specific treatment for this disease, but there are currently few standardized treatment recommendations for these patients.
In the general population, a class of drugs called bisphosphonates are considered the most appropriate treatment. Specifically zoledronic acid is used in post-menopausal women, who often have osteoporosis. The aim of the VIHZOL study was to evaluate the efficacy and tolerability of this drug in HIV patients by comparing two dosing schedules: once a year, or once every two years.
To do this, participants (people with HIV and osteoporosis) were divided into three groups: those who would receive a dose of zoledronic acid every year, those who would receive it every two years and the control group (people not receiving the drug). At baseline, all patients underwent a blood test, as some laboratory markers are useful for monitoring bone activity. Bone densitometries (DEXA's ) were also performed: this tests are used to measure bone density. All participants received dietary advice to combat osteoporosis, but zoledronic acid was administered only to the first two groups (all patients except those in the control group). After one year, analysis and DEXAS were performed agian to all participants but then only half of the patients who received the first dose at baseline, received a second dose if zoledronic acid. A year later the study was concluded after performing the tests to all participants once again (analysis and DEXA).
After comparing the results, the conclusion is that the use of zoledronic acid every two years has the same benefits as an annual administration. It is always advisable to use the lowest possible dose of drug to achieve the desired therapeutic effect, avoiding toxicities and reducing costs.