Which pamidronate protocol is the best for treating osteoporosis in beta-thalassemia major?

Abstract

One of the most common complications in thalassemia major patients is osteopenia and osteoporosis. In this study, we compare the therapeutic effect of two treatment protocols involving infusion of 45 mg of pamidronate injection every 6 weeks (P45) and 90 mg pamidronate infusion every 4 weeks (P90). Bone mineral density was measured using dual energy X-ray absorptiometry (DEXA). Z-score of lumbar vertebra (as L total) and the femoral head (as F total) were compared before and after administration of two protocols. Bone density between the two groups was compared by Student t test and by the paired t test before and after the intervention. Data were analyzed using SPSS (18). Ninety-one patients were treated with pamidronate 45 mg (P45), and 36 patients were treated with pamidronate 90 mg (P90). Ninety-one and 36 patients received P45 and P90 protocol, respectively. Mean age was 29.4 ± 8.1 and 30.9 ± 8.0 years old in P45 and P90 groups, respectively. Sixty-two and 58 % of P45 and P90 group were female. The means of F total were -1.73 ± 1.11 and -1.47 ± 0.92 before and after treatment in patients P45 (P = 0.01) and were -1.83 ± 0.75 and -1.57 ± 0.99 in group P90 (P = 0.005), respectively. Before treatment, the means of L total were -2.95 ± 0.81 and -2.92 ± 0.66 (P = 0.8) and after treatment were -2.53 ± 1.13 and 2.81 ± 0.98 (P = 0.1) in P45 and P90 groups, respectively. In P45, between the mean of L total was statistically significant difference before and after treatment (P < 0.0001); however, there was no significant difference in the P90 group (P = 0.3). The study showed effectiveness of both protocols. As the medication is expensive and should be administrated parenterally, we recommend P45 protocol which is less expensive with fewer injections.