Intravenously administered pamidronate in the treatment of Paget's disease of bone

ZOLEDRONIC ACID THERAPY OF PATIENTS WITH PAGET DISEASE OF BONE RESISTANT TO OR WITH UNSUSTAINED REMISSION FOLLOWING PRIOR BISPHOSPHONATE THERAPY

OBJECTIVE

To evaluate the effect of zoledronic acid (ZA) in patients with Paget disease (PD) who had not had a biochemical remission with prior bisphosphonate therapy or had a remission ≤12 months.

METHODS

The effects of ZA therapy were studied in 14 patients aged 54 to 90. Serum alkaline phosphatase (ALP) levels were elevated to at least 40% above the normal reference range, and glomerular filtration rates (GFRs) were ≥40 mL/minute. ZA (5 mg) was infused over 15 minutes. ALP and urine N-telopeptide/creatinine (NTx/Cr) were obtained before therapy and at 3, 6, 9, and 12 months, and thereafter at 4-month intervals.

RESULTS

At baseline, ALP ranged from 141 to 1,009 U/L. In 13 patients, ALP fell to normal following ZA administration. Remissions occurred in 9 patients who had not previously had a remission. Remissions varied from 12 to 60 months and were more prolonged in 4 patients with prior remissions ≤12 months. ZA failed to induce a remission in 1 patient. Ten to 12 days after therapy in 3 asymptomatic patients, serum calcium levels fell to 7.9, 8, and 8.3 mg/dL. Other than flu-like symptoms in 3 patients after ZA infusion, there were no other adverse effects.

CONCLUSION

Therapy with ZA induced remissions in 13/14 patients and induced more prolonged remissions in patients who previously had remissions ≤12 months. The lack of remission in 1 patient despite 2 courses of therapy is evidence of a continuing therapeutic challenge for some patients with a more resistant form of PD.

Paget's Disease of Bone: A Review of Epidemiology, Pathophysiology and Management

Paget's disease of bone is a common disorder which may affect one or many bones. Although many patients are asymptomatic, a variety of symptoms and complications may occur. Fortunately, effective pharmacologic therapy, primarily with potent bisphosphonates, is now available to treat patients with complications or symptoms. This review of Paget's disease of bone will include epidemiology and pathophysiology, complications and clinical findings, indications for treatment, and the drugs currently available to treat this condition.

[Usefulness of Pamidronate in the Treatment of Charcot's Arthropathy]

OBJECTIVE

To investigate the usefulness of pamidronate in the management of active Charcot's arthropathy.

MATERIAL AND METHODS

Open prospective study with a follow-up of 12 months, including patients with active neuroarthropathy seen over a period of 3 years in our rheumatology unit. Patients received three pamidronate infusions at 0, 2, and 4 months. Clinical assessment, serum and urine bone turnover markers, radiological exam, and scintigraphy were performed before and after treatment.

RESULTS

Seven patients were ncluded (4F/3M), mean age, 51.3 years (30-64). The underlying disease was diabetes mellitus in 4 cases, syringomyelia in 2, and sensory and autonomic neuropathy in 1. The joints affected were shoulder, ankle, tarsians, metacarpophalaneal, and metatarsophalangeal. All patients showed a rapid resolution of clinical symptoms, with a clear reduction of all bone remodeling markers that achieved statistical significance for urine NTX and urinary pyridoline (P=.04 and P=.03, respectively). Six of 7 patients disclosed at the end of follow-up a radiological healing. Quantitative scyntigraphy showed a clear reduction of the bone (99)Tm uptake. No important side affects were reported.

CONCLUSIONS

Pamidronate appears as a useful treatment for neuroarthropathy independently of the underlying disease. A rapid diagnosis and early pamidronate treatment could avoid severe articular consequences.

Comparison of different intravenous bisphosphonate regimens for Paget's disease of bone

This randomized study compared different intravenous bisphosphonates in PDB. Zoledronate was superior with respect to pamidronate in achieving biochemical remission, with therapeutic response maintained in most patients at 15 mo. Single neridronate and zoledronate infusion showed a similar efficacy in up to 90% of patients nonresponders to pamidronate.

INTRODUCTION

Intravenous bisphosphonates represent a common therapy for Paget's disease of bone (PDB). However, there have been few head to head randomized trials comparing intravenous bisphosphonates.

MATERIALS AND METHODS

We performed a 15-mo, randomized study comparing different intravenous bisphosphonates in 90 subjects with active PDB. At baseline, patients were randomly assigned to receive pamidronate (30 mg, i.v., for 2 consecutive days every 3 mo; n = 60) or zoledronate (4 mg, i.v.; n = 30). After 6 mo, nonresponders to pamidronate were crossed over to zoledronate or neridronate (100 mg, i.v., for 2 consecutive days). The primary efficacy endpoint was therapeutic response at 6 mo, defined as normalization of alkaline phosphatase (ALP) or a reduction of at least 75% in total ALP excess.

RESULTS

At 6 mo, 97% of patients receiving zoledronate had a therapeutic response compared with 45% of patients receiving pamidronate. Normalization of ALP was achieved in 93% of patients in the zoledronate group and in 35% of patients in the pamidronate group. ALP normalization was maintained in 79% and 65% of zoledronate-treated patients after 12 and 15 mo, respectively; loss of therapeutic response was observed in 2 of 30 (6%) at 12 and 15 mo. At 6 mo, 27 patients showing therapeutic response to pamidronate continued the treatment, whereas nonresponders were crossed-over to neridronate (n = 15) or zoledronate (n = 18). Among these subjects, 14 of 15 (93%) in the neridronate group and 17 of 18 (94%) in the zoledronate group achieved a therapeutic response. Similar normalization rates were observed between neridronate- (80%) and zoledronate- (83%) treated subjects. Normalization and therapeutic response were maintained at 9 mo from treatment (corresponding to 15 mo from the baseline visit) in either neridronate or zoledronate groups.

CONCLUSIONS

Single neridronate and zoledronate infusion showed a similar efficacy in achieving biochemical remission in up to 90% of patients nonresponders to pamidronate. Therapeutic response to zoledronate seems to be maintained in most patients at 15 mo.

Amino-bisphosphonates in heterotopic ossification: first experience in five consecutive cases

STUDY DESIGN

Retrospective, observational study in five consecutive cases.

OBJECTIVES

The management of heterotopic ossification (HO), a frequent complication after spinal cord injury (SCI) and after orthopaedic surgery, is a therapeutic challenge with high recurrence rates of over 50%. Conflicting data were reported for Etidronate. The use of the more potent new generation of amino-bisphosphonates has been put forward in different inflammatory, dysmorphogenic bone disease. In order to try and halt the underlying dysfunctional bone metabolism we have studied the action of pamidronate in five consecutive high-risk patients with established HO of different etiology undergoing surgical removal.

SETTING

University Hospital of Basel, Switzerland, Division of Endocrinology, Diabetology and Clinical Nutrition and the Department of Orthopedic Surgery.

METHODS

In all five patients, ranging from 47 to 68 years of age, we used continuous pamidronate infusions perioperatively at a dosage of 120 mg in the first 12 h and subsequent reduction to 75-60-30-15 mg/12 h over a period of 10-14 days.

RESULTS

None of these patients showed clinical, radiographical and laboratory signs of HO recurrence or new forming HO in the follow-up 5-54 month after surgery. Potential side effects of high-dose bisphosphonate therapy such as osteoporosis and osteomalacia were not reported in any case.

CONCLUSION

We postulate that pamidronate might have pronounced beneficial effects in high-risk patients with established HO undergoing excision surgery. Since the therapeutic window of amino-bisphosphonates has not yet been defined and the minimal necessary doses for preventing new HO are unknown, further studies are encouraged to confirm our findings and to identify the necessary dosage and duration of treatment and to pinpoint, which patients will benefit most from this treatment.

The usefulness of bone remodelling markers in predicting the efficacy of pamidronate treatment in SAPHO syndrome

OBJECTIVES

Pamidronate has recently been used in SAPHO syndrome due to its anti-osteoclastic effect. The aim of this study is to determine the usefulness of bone remodelling markers for determining the efficacy of pamidronate treatment.

METHODS

Thirteen patients with SAPHO syndrome were treated with pamidronate. The treatment evaluation was done using a visual analogue scale (VAS) and also erythrocyte sedimentation rate, C-reactive protein, serum crosslaps (sCTX) and osteocalcin initially and after 3 months. A relevant clinical response was defined as an improvement in VAS of at least 40%.

RESULTS

At 3 months, 7 of 13 patients had a good clinical response, as previously defined. Five of the seven patients maintained the good response over 6 months. Before the first perfusion 6 of the 13 patients had increased sCTX (upper 3250 pmol/l). In this small cohort we tried to analyse whether the increase in bone remodelling markers was associated with a good clinical response. In the responders group the mean levels of sCTX and osteocalcin at baseline were 6783.17 and 24.66, respectively, and in the non-responders group the levels were 2152 and 11.8, respectively. There was a significant difference in sCTX between the responders and the non-responders (P = 0.0044).

CONCLUSION

Infusion of pamidronate is effective in SAPHO in some patients. Increased sCTX might be a prognostic marker for a good clinical response but results have to be confirmed in a larger cohort.

Discovery, clinical development, and therapeutic uses of bisphosphonates

OBJECTIVE

To review the literature concerning the history, development, and therapeutic uses of bisphosphonates.

DATA SOURCES

English-language articles were identified through a search of MEDLINE (through December 2004) using the key word bisphosphonate. Reference lists of pivotal studies, reviews, and full prescribing information for the approved agents were also examined.

STUDY SELECTION AND DATA EXTRACTION

Selected studies included those that discussed the discovery and initial applications of bisphosphonates, as well as their historical development, pharmacokinetic and pharmacodynamic properties, and current therapeutic uses.

DATA SYNTHESIS

Bisphosphonates structurally resemble pyrophosphates (naturally occurring polyphosphates) and have demonstrated similar physicochemical effects to pyrophosphates. In addition, bisphosphonates reduce bone turnover and resist hydrolysis when administered orally. The information gained from initial work with etidronate generated a considerable scientific effort to design new and more effective bisphosphonates. The PCP moiety in the general bisphosphonate structure is essential for binding to hydroxyapatite and allows for a number of chemical variations by changing the 2 lateral side chains (designated R(1) and R(2)). The R(1) side chain determines binding affinity to hydroxyapatite, and the R(2) side chain determines antiresorptive potency. Accordingly, each bisphosphonate has its own characteristic profile of activity.

CONCLUSIONS

The bisphosphonates reduce bone turnover, increase bone mass, and decrease fracture risk and therefore have a significant place in the management of skeletal disorders including osteoporosis, Paget's disease, bone metastases, osteogenesis imperfecta, and heterotopic ossification.

Bisfosfonatos intravenosos

Bisphosphonates possess a fundamental role in the treatment of bone metabolic diseases. Yet their main limitations are poor oral absorption and gastrointestinal side effects, mainly esophageal irritation. Indeed, oral administration is unpleasant for many patients, and it is difficult in bed-confined subjects. Therefore, intravenous administration of these agents can be very useful in several clinical scenarios, especially to improve the compliance. Recently, it has been showed that intravenous bisphosphonates are very useful to control hypercalcemia of malignancy, and to prevent bone complications related to metastases. Their use has also been analyzed in the prevention of bone disease after organ transplantation. Thus, their application to control Paget's disease of bone is well-known, and probably they could have an important role as antiresorptive agents in postmenopausal and steroidal osteoporosis. We present here a state of the art of the use of intravenous bisphosphonates for the aforementioned disorders.

Paget's disease: a case in point

Paget's disease (PD) is the second most common bone disease in older adults, yet many clinicians are unfamiliar with it and may not consider it a diagnostic possibility. This article uses a case study to introduce the topic of Paget's disease. The definition, incidence, and etiology of PD is addressed. Normal bone physiology is defined in contrast to the pathophysiology of PD. Patient history, laboratory tests, and imaging studies are summarized with regard to the diagnosis of PD. Treatment options are discussed including pharmacologic management and prognosis. The article concludes with implications for nursing care of the patient with PD.