Comparison of two different strategies of treatment with zoledronate in HIV-infected patients with low bone mineral density: single dose versus two doses in 2 years

Objectives Given the need for easily managed treatment of osteoporosis in HIV-infected patients, we evaluated the efficacy and tolerability of two doses of zoledronate, by comparing three groups of patients: those with annual administration, those with biennial administration (one dose in 2 years) and a control group with no administration of zoledronate. Methods We randomized (2:1) 31 patients on antiretroviral therapy with low bone mineral density (BMD) to zoledronate (5 mg administered intravenously; 21 patients) plus diet counselling and to a control group (diet counselling; 10 patients). At week 48, patients treated with zoledronate were randomized again to receive a second dose (two-dose group; n = 12) or to continue with diet counselling only (single-dose group; n = 9). Changes in lumbar spine and hip BMD and bone turnover markers were compared. Results The median percentage change from baseline to week 96 in L1−L4 BMD was −1.74% [interquartile range (IQR) −2.56, 3.60%], 7.90% (IQR 4.20, 16.57%) and 5.22% (IQR 2.02, 7.28%) in the control, two-dose and single-dose groups, respectively (P < 0.01, control vs. two doses; P = 0.02, control vs. single dose; P = 0.18, two doses vs. single dose). Hip BMD changed by a median of 2.12% (IQR −0.12, 3.08%), 5.16% (IQR 3.06, 6.74%) and 4.47% (IQR 1, 5.58%), respectively (P = 0.04, control vs. two doses; P = 0.34, two doses vs. single dose). No differences between the two-dose and single-dose groups were detected in bone markers at week 96. Conclusions The benefits for BMD of a single dose of zoledronate in 2 years may be comparable to those obtained with two doses of the drug after 96 weeks, although this study is insufficiently powered to exclude a real difference. Future studies should explore whether biennial administration of zoledronate is a useful alternative in the treatment of osteoporosis in HIV-infected patients.