Intravenous pamidronate in the treatment and prevention of osteoporosis

Effects of intravenous pamidronate on renal function, bone mineral metabolism and bone mass in patients with severe osteoporosis

INTRODUCTION

To analyze the effects of intravenous pamidronate (APD) on bone remodelling, bone mineral density (BMD), fractures and bone mineral metabolism parameters, and the rate of adverse events, with special attention to renal function, in patients with osteoporosis with intolerance and/or any contraindication to oral bisphosphonates.

METHODS

We analyzed prospectively 17 osteoporotic patients (age, 66.8 +/- 9.4 years): 65% women, 82% with prevalent vertebral fractures. All patients received APD therapy (30 mg intravenously every 3 months) and were followed up for 1 year. We analyzed serum amino-terminal propeptide of type I procollagen and urinary N-terminal cross-linked telopeptide of type I collagen (as markers of bone turnover), serum calcium, phosphate, parathormone, 25OH-vitamin D, creatinine, and the creatinine clearance: at baseline, 1 week after starting APD treatment, and thereafter for every 3 months (before infusion) during 1 year. We also analyzed lumbar and femoral BMD at baseline and after 1 year, the incidence of new fractures, and the treatment-related adverse events.

RESULTS

One week after starting APD treatment, a significant decrease of N-terminal cross-linked telopeptide of type I collagen (32%) (P < 0.05) and an increase of parathormone values (72%) (P < 0.01) were observed, without significant differences found thereafter. No significant differences were observed in BMD evolution and in the other parameters analyzed throughout the study, nor in impairment of renal function. Sixty-four percent of patients suffered new skeletal fractures, 41% of patients showed flu-like syndrome after APD infusion, and 1 patient was withdrawn from treatment because of adverse events.

CONCLUSION

Patients with severe osteoporosis receiving APD infusions had a high rate of fractures without significant changes in bone mass or in bone markers; nevertheless, such a therapeutic regimen showed a good renal safety profile, suggesting that APD at this dosage is safe but ineffective for treating severe osteoporosis.

Renal safety of intravenous bisphosphonates in the treatment of osteoporosis

Oral bisphosphonates are the mainstay of treatment for osteoporosis but cannot be used in some patients due to gastrointestinal contraindications, gastrointestinal intolerance, malabsorption or the inability to comply with dosing requirements. In such patients, intravenous bisphosphonates are a useful alternative. This review summarises the renal safety issues associated with the use of intravenous bisphosphonates for osteoporosis. Intravenous bisphosphonates are generally well tolerated, which may be a reflection of their selective activity in bone and metabolic stability. Adverse effects on renal function are primarily related to infusion rate and dose. Due to lack of data, no conclusions can be made regarding bisphosphonate safety in patients with intrinsic renal disease or an estimated glomerular filtration rate of < 30 ml/min.

Pamidronate reduces bone loss after allogeneic stem cell transplantation

BACKGROUND

Rapid bone loss occurs from the proximal femur after allogeneic stem cell transplantation (alloSCT).

OBJECTIVE

The objective of the study was to evaluate effects of high-dose pamidronate therapy on bone loss (BMD) after alloSCT.

DESIGN

This was a randomized, multicenter, open-label, 12-month prospective study of iv pamidronate (90 mg/month) beginning before conditioning vs. no pamidronate. All 116 patients also received calcitriol (0.25 microg/d) and calcium (1000 mg/d), which were continued for another year.

MAIN OUTCOME MEASURES

Primary objectives were to compare changes in BMD 12 months after alloSCT at the femoral neck, lumbar spine, and total hip between the treatment arms and assess influences of glucocorticoid and cyclosporin therapy on these changes.

RESULTS

Pamidronate reduced bone loss at the spine, femoral neck, and total hip by 5.6, 7.7, and 4.9% (all P < or = 0.003), respectively, at 12 months. However, BMD of the femoral neck and total hip was still 2.8 and 3.5% lower than baseline, respectively (P < 0.05) with pamidronate. Only differences at the total hip remained significant between the two groups at 24 months. Benefits were restricted to patients receiving an average daily prednisolone dose greater than 10 mg and cyclosporin therapy for more than 5 months within the first 6 months of alloSCT.

CONCLUSIONS

Pamidronate markedly reduced but did not completely prevent postallogeneic bone marrow transplantation bone loss. BMD benefits were greatest in patients on higher doses of immunosuppressive therapy, but most were lost 12 months after stopping pamidronate. Studies of more potent bisphosphonates or anabolic therapy with PTH after alloSCT are warranted with the aim of durable maintenance of bone mass.

Postmenopausal osteoporosis. What have we learned since the introduction of bisphosphonates?

Over the past 12 years bisphosphonates have become a mainstay of treatment for postmenopausal osteoporosis. As a class, bisphosphonates significantly suppress bone turnover and increase BMD at the lumbar spine and other site through their direct inhibitory effects on osteoclasts. Alendronate and risedronate reduce the incidence of clinical vertebral and non-vertebral fractures. Etidronate and both oral and intravenous ibandronate reduce the incidence of clinical vertebral fractures, but data from primary analyses for reduction in non-vertebral fractures are currently less robust. Intravenous administration of zoledronate is under late-stage investigation for use in postmenopausal osteoporosis. Combinations of alendronate with estrogen or raloxifene provide a greater reduction in bone turnover markers and greater increases in BMD, but fracture risk reduction has not been determined. Overall, bisphosphonates are well tolerated. The most common side effects of oral bisphosphonates are upper gastrointestinal symptoms. Newer safety concerns about the use of bisphosphonates include osteonecrosis of the jaw and oversuppression of bone turnover. The optimal duration of bisphosphonate treatment has not been clearly established.

Oral ibandronate: a less frequently administered therapeutic option for postmenopausal osteoporosis

Osteoporosis is a severe condition, associated with significant disability as a result of fragility fractures and increased mortality. Oral bisphosphonates effectively reduce the risk of osteoporotic fracture and are generally well tolerated. Unfortunately, patient outcomes are often compromised by suboptimal therapeutic adherence. In other disease areas, reduced dosing frequency has been shown to improve therapeutic adherence. A positive impact for adherence has been observed with a reduction in the bisphosphonate dosing frequency from daily to weekly. However, overall adherence remains suboptimal. Ibandronate is a potent nitrogen-containing bisphosphonate specifically designed for less frequent than weekly administration, without compromise for efficacy or tolerability. This article reviews the pharmacology, efficacy and tolerability of oral ibandronate when administered with extended dosing intervals in postmenopausal osteoporosis.

Osteoporosis in Systemic Lupus Erythematosus Mechanisms

Osteoporosis is a potentially preventable condition frequently encountered in patients who have systemic lupus erythematosus (SLE). Bone loss in SLE is heterogeneous and likely a multifactorial process involving both traditional and lupus-related risk factors. Recognizing potential contributors to bone loss in the SLE patient may allow for earlier detection of osteoporosis and optimize bone health. This article reviews the current epidemiologic information available on osteoporosis and fracture data in SLE and discusses evaluation and management strategies pertinent to patients who have lupus.