A 57 y/o female patient comes to the clinic for her annual physical. She's had all her routine screenings done (mammogram, pap smear, CHOL, etc). She has no other health problems but is on hormone replacement therapy (HRT) for prevention of post menopausal symptoms and ossteeoporosis. Being a rather Internet-savvy patient, she asks you about the new once a year treatment for prevention of osteoporosis she found on the Web and asks you to prescribe it for her.

What's your answer? Prescribe it or not? Why or why not?

Don't prescribe this one .... yet.

The drug, zoledronate [Zometa®], is an intravenous biphosphonate similar to alendronate and pamidronate. It's another osteoclastic inhibitor and is currently only indicated for hypercalcemia of malignancy. It appears to be at least as effective as IV pamidronate for lowering serum calcium levels. Its' advantages appear to be shorter infusion times (15 minutes vs 2-24 hours) and maybe a higher, more prolonged rate of normocalcemia after treatment.

In regards to our pearl, one preliminary study (n=351) showed that a one time IV infusion of 4mg of zoledronate suppressed bone resorption for up to 12 months and increased bone mineral density in both the lumbar spine and femoral neck. This study has only been published in abstract form to date.

Although this may represent an advantage in the prevention of post-menopausal osteoporosis, it's far too early to recommend this once a year IV infusion. Further studies are necessary to clarify its' place in prevention of osteoporosis. I would recommend to this patient that she continue with her HRT until further information is available to support the use of this drug for this indication. The patient should be advised to maintain adequate calcium (1,200 - 1,500 mg/day) and Vitamin D intake (RDA = 400 IU/day), adequate exercise, stop smoking, limit alcohol consumption, etc.

Reference:

- JP Brown et al, J Bone Miner Res 2001;16:S218, F353.

- The Medical Letter 2001;43:110-1