Lack of difference in acute nephrotoxicity of intravenous bisphosphonates zoledronic acid and ibandronate in women with breast cancer and bone metastases

BACKGROUND

More than 50% of patients with advanced breast cancer develop bone metastases that may lead to multiple complications such as pathological fractures, bone pain or hypercalcaemia. The standard treatment, besides endocrine, targeted-therapy or chemotherapy, is the use of bisphosphonates. However, one of their main adverse side-effects is bisphosphonate-induced nephrotoxicity. The mechanism by which the latter occurs is not well-understood, although emerging evidence suggests that the effect of bisphosphonates on the kidney may differ between agents.

PATIENTS AND METHODS

The aim of this evaluation was to compare the renal toxicity of 6 mg ibandronate i.v. versus 4 mg zoledronic acid i.v. over a period of six months in women with breast cancer and bone metastases. A prospective randomized trial was carried out to examine specific kidney and other parameters (α1- and β2-microglobulin, albumin, α2-macroglobulin, IgG and C-reactive protein (CRP) generated from spontaneous urine samples from 17 patients of each group.

RESULTS

We were unable to find any significant difference between the two treatment groups with regard to renal toxicity. All patients, independently of the applied bisphosphonate, experienced only temporary renal dysfunction without any evidence of irreversible damage in terms of acute nephrotoxicity during the study period. α1-Microglobulin, a marker for proximal tubular damage, in particular, was not differently elevated in either group.

CONCLUSION

Both applied bisphosphonates were found to be well-tolerated and safe with regard to renal toxicity during a six-month treatment period in patients with otherwise healthy kidneys having advanced breast cancer and bone metastases.

[Prevention of complications in twin gestations and pregnancies after assisted reproduction]

BACKGROUND

Twin pregnancies and gestations after assisted reproductive therapy (ART) are of special obstetric significance with regard to their associated risks. However, little is known about preventive approaches specifically evaluated for these constellations.

METHODS

A selective literature search was conducted to examine possible preventive approaches for complications such as hypertensive disorders, anaemia, gestational diabetes, prematurity, and others, seen significantly more often in twin gestations and pregnancies after ART.

RESULTS

For both constellations, preventive approaches are not specifically evaluated for the majority of complications. For some preventive methods a possible detrimental effect cannot even be ruled out.

CONCLUSIONS

The knowledge about specific preventive approaches against complications in twin pregnancies and gestations after ART is scarce. More prospective trials are urgently needed to assess the risks and benefits of prophylactic approaches for these risk constellations.