APD in Paget's disease of bone. Role of the mononuclear phagocyte system?

Zoledronic acid-induced severe lymphopenia

Although anemia, thrombocytopenia, and mild lymphopenia have been reported in the acute phase response after zoledronic acid, severe lymphopenia has not been reported. This article describes a case of severe lymphopenia following a 5 mg zoledronic acid infusion administered to treat osteoporosis. Zoledronic acid is used to treat osteoporosis, hypercalcemia, Paget's disease, and solid malignancies, including multiple myeloma, breast cancer, and prostate cancer. An acute phase response can be seen in 42% of patients after zoledronic acid treatment. Acute phase response may be accompanied by short-term spontaneously recovered anemia, thrombocytopenia, and severe lymphopenia.

Sternocostoclavicular Hyperostosis: Positive Clinical and Radiological Response on Pamidronate

BACKGROUND

Sternocostoclavicular hyperostosis (SCCH) is a rare disease, constituting a chronic sterile osteomyelitis with elevated bone turnover in the axial skeleton, causing pain and shoulder dysfunction. SCCH severely interferes with daily activities, work, and quality of life. SCCH has a relapse-remitting disease course, but inflammatory-induced sclerotic transformation in the affected area is slowly progressive. Here we present two patients with clinical and radiological diagnosis of SCCH treated with intravenous pamidronate, leading to clinical remission in both, but complete resolution of sclerosis in one of them, which is a novel finding in our experience.

CASE PRESENTATION

Two adult female SCCH-patients presented with longstanding pain, swelling of the anterior chest wall, and compromised shoulder function. Subsequent single photon emission computed tomography-computed tomography (SPECT/CT) illustrated elevated bone activity and sclerosis in the SC region, with hyperostosis, confirming the diagnosis of SCCH. As symptoms in both patients were eventually refractory to standard painkillers such as non-steroidal anti-inflammatory drugs (NSAIDs), intravenous pamidronate treatment in 3-month cycles was started. Pamidronate was effective in reducing pain and improving shoulder function and also led to decreased bone turnover on skeletal scintigraphy. Sclerosis in the first patient persisted. In the second patient, however, a complete resolution of sclerosis was observed.

CONCLUSIONS

SCCH remains a rare bone disorder for which no evidence-based therapies are yet available. While disease burden is high, SCCH lacks recognition and is often diagnosed long after symptomatic presentation. As for the cases in this report, pamidronate was successful in reducing symptoms, and in the second case even led to regression of sclerotic changes on CT-imaging.

Pamidronate: A model compound of the pharmacology of nitrogen-containing bisphosphonates; A Leiden historical perspective

Pamidronate [3-amino-1-hydroxypropylidene-1,1-bisphosphonate (APD)] was the first nitrogen-containing bisphosphonate (N-BP) investigated in clinical studies. In contrast to other clinically used bisphosphonates, pamidronate was discovered and its properties were initially studied in an Academic Institution. On the occasion of the 50th Anniversary of the first publications on the biological effects of bisphosphonates, I review in this article the contribution of Leiden investigators to the development of pamidronate that led to the recognition of the significance of the Nitrogen atom in the side chain of bisphosphonates for their action on bone resorption and to the formulation of principles for the use of N-BPs in the management of patients with different skeletal disorders.

Management of Paget's disease of bone

Paget's disease is a progressive focal bone condition which can result in pain, low quality of life, deformity and other complications. Disease progression can be halted with potent bisphosphonates, resulting in improvement in both quality of life and pain, and normalisation of scintigraphy, plain radiographs and bone histology. Zoledronate has transformed the treatment of Paget's disease, producing sustained remissions in almost all patients. Thus, it is now possible to normalise bone cell activity and prevent disease progression at low cost, with one or two intravenous injections of zoledronate, greatly reducing follow-up costs. Patients with Paget's disease who are symptomatic or at risk of complications should have the opportunity to reap these therapeutic benefits. Potent bisphosphonates are highly effective in halting disease progression in Paget's disease, but guidelines disagree about treatment indications. The efficacy, safety and low cost of zoledronate recommend its use in any patient who is symptomatic or judged to be at risk of complications from Paget's disease.

Role of Pamidronate Disodium in the Treatment of Metastatic Bone Disease

Aims and Background

Bone metastases are a common feature of advanced neoplastic disease and are considered to be among the most frequent causes of pain and complications in oncologic patients. The main objective of the treatment of such patients is to control their symptoms and improve their quality of life. Pamidronate disodium is a second-generation bisphosphonate capable of inhibiting bone resorption (particularly osteoclast activity) without affecting bone reminerali-zation. After a brief introduction concerning the pathophysiology of bone metastases and neoplastic bone pain, we herein present data on the clinical pharmacology and toxicity of bisphosphonates in general, and pamidronate in particular. We conclude by reviewing the literature on the use of pamidronate in phase II and III trials involving patients with metastatic bone disease.

Methods

The paper is based on a review of articles published between 1984 and 1997 selected from the Cancerline and Medline databases.

Results

In the considered phase II and III studies involving patients with bone metastases (breast cancer and multiple myeloma in particular), pamidronate proved to be efficacious in reducing the incidence of pain and skeletal complications, decreasing the excretion of metabolic markers of bone resorption and improving the quality of life. Intravenous infusions of 60-90 mg over a period of 2 hr every 3-4 weeks did not cause any significant toxic effects and was easily managed.

Conclusions

Pamidronate is a bisphosphonate that is efficacious in the treatment of symptomatic bone metastases and can be considered an important therapeutic option in association with systemic treatments, radiotherapy and normal supportive care, especially in patients with breast cancer and multiple myeloma. Further randomized studies are necessary to confirm the positive preliminary results in other neoplasms, analyze the cost/benefit ratio of the treatment, and verify the possibility that, in addition to being used for palliative purposes, pamidronate may also prevent or delay the appearance of bone metastases.

Acute phase response following intravenous zoledronate in postmenopausal women with low bone mass

An acute phase response (APR) is frequently observed in patients treated with intravenous (i.v.) zoledronate (ZOL). We aimed to define clinical and laboratory parameters that may predict ZOL-induced APR in women with low bone mass. Fifty-one postmenopausal women with low bone mass were given a single i.v. infusion of ZOL 5mg. APR was clinically defined by the visual analog pain scale (VAS) for the musculoskeletal symptoms and body temperature. White blood cell count (WBC), leucocyte subpopulations, C-reactive protein (CRP), parathyroid hormone (PTH), 25-hydroxyvitamin D [25(OH)D], interleukins (IL)-1b and -6, tumor necrosis factor (TNF)α and interferon (IFN)γ were measured before and 48 h following the infusion. Subsequently, patients were divided into those experiencing APR (APR+) or not (APR-). WBC, granulocytes, CRP, IL-1b and IL-6 were significantly increased, whereas lymphocytes, eosinophils, calcium, phosphate and 25(OH)D decreased 48h after ZOL infusion. Twenty-eight of the 51 patients (54.9%) experienced an APR. APR+ patients were younger and had higher baseline lymphocytes compared to APR- patients. There was no difference (p=0.405) in the development of APR between treatment-naive patients (19/32, 59.4%) and patients previously treated with another oral nitrogen-containing bisphosphonate (9/19, 47.4%). In conclusion, our data suggest that pre-treatment higher lymphocyte number increases the risk of APR while previous treatment with another nitrogen-containing bisphosphonate does not significantly reduce the risk. Serum 25(OH)D concentrations decrease significantly after the infusion, possibly as part of the inflammatory response to ZOL.

Treatment of Paget's disease of bone

Paget's disease of bone is the paradigm of bone focal distortion with accelerated bone turnover. Over the years, a number of different drugs have been used to control its activity but, since biphosphonates were introduced for the treatment of the disease, they have become the preferred treatment. This review will update the therapeutic indications, available drugs and therapeutic response monitoring.

Circulating γδ T cells and the risk of acute-phase response after zoledronic acid administration

The use of intravenous nitrogen-containing bisphosphonates (N-BPs) is associated with the appearance of an acute phase response (APR) in a proportion of the patients for reasons that are poorly understood. The APR was attributed to the indirect activation of γδ T cells with the release of interferon-γ and tumor necrosis factor (TNF). Forty patients with postmenopausal or senile osteoporosis (age range = 53-91 years) never previously treated with intravenous (i.v.) bisphosphonate, received a single 5-mg zoledronic acid (ZOL) iv infusion over 15 minutes. White blood cells were counted and analyzed with an automated hematology analyzer (ADVIA 2120i Siemens, New York, USA) and by flow cytometer (BD FACSCanto, Becton Dickinson). The occurrence of APR was defined by the occurrence of fever (>37 °C) during the next 2 days. Forty-two percent of patients (17 of 40) receiving the infusion of ZOL experienced an APR. Compared with the others they were younger (69 ± 7 years versus 74 ± 8 years; p = 0.06), and both the proportion and absolute number of γδ T cells were significant higher (p = 0.02 and p = 0.013, respectively). Nonsignificant differences were found between the two groups for white blood cells and for the other circulating lymphocyte subpopulations. Age was inversely correlated with circulating γδ T cells (p = 0.003) but the difference between the two groups in circulating γδ T cells persisted for age-adjusted values and vice versa. In conclusion, the results of this study indicate that the number of circulating γδ T cells, together with age, are important determinant of the occurrence of APR after intravenous infusion of ZOL and possibly of any other N-BPs.

Bisphosphonates in Paget's disease

Paget's disease is the best example of a common high turnover bone disease. A review of the early use of bisphosphonates in the treatment of this condition shows that many of the fundamental therapeutic issues were identified using drugs which by today's standards were far from ideal. Over the succeeding decades there has been a steady increase in potency culminating in the introduction of intravenous zoledronic acid which is capable of inducing long term remissions which were unthinkable when bisphosphonates were first introduced.

No effect of rosuvastatin in the zoledronate-induced acute-phase response

The acute-phase response (APR) is frequently observed in patients treated with intravenous (iv) zoledronate (ZOL). We investigated whether a short course of rosuvastatin (ROSU) could attenuate the ZOL--induced APR through blocking the mevalonate pathway at a proximal level. Twenty-eight osteoporotic postmenopausal women with no prior bisphosphonate use (mean age 65.3 ± 1.9 years) were subjected to ZOL iv infusion. Patients were randomly assigned into either a ROSU+ group (n = 12), which received ROSU 10 mg/day starting 5 days before the infusion of ZOL for a total period of 11 days, or a ROSU- group (n = 16), which did not receive ROSU. The visual analog pain scale (VAS) for musculoskeletal symptoms and body temperature was used to define clinically APR. In addition, white blood cell (WBC) count, leukocytic subpopulations, and C-reactive protein (CRP) were obtained before and 48 h following the infusion. Seven (58.3%) patients in the ROSU+ group and 13 (81.3%) in the ROSU- group experienced APR (P = not significant). No difference was found in fever and VAS measurements. CRP and granulocytes increased significantly in both groups; WBC count increased, while lymphocytes and eosinophils decreased significantly only in the ROSU- group. In a post hoc analysis of only patients with an APR, all laboratory parameters exhibited a similar significant change solely within the ROSU- group. In conclusion, our data suggest that a short course of ROS at this dose cannot prevent the ZOL-induced APR among osteoporotic women. Milder changes in acute-phase laboratory parameters in ROSU+ patients suggest that studies with higher doses may be warranted.

Characterization of and risk factors for the acute-phase response after zoledronic acid

CONTEXT

Intravenous aminobisphosphonates often cause an acute-phase response (APR), but the precise components of this, its frequency, and the risk factors for its development have not been systematically studied.

OBJECTIVE

The objective of the study was to characterize the APR and determine its frequency and the risk factors for its development.

DESIGN

The study was an analysis of adverse events from a large randomized trial.

SETTING

This was a multicenter international trial.

PATIENTS

Patients included 7765 postmenopausal women with osteoporosis.

INTERVENTION

Zoledronic acid 5 mg annually or placebo was the intervention.

MAIN OUTCOME MEASURE

Adverse events occurring within 3 d of zoledronic acid infusion were measured.

RESULTS

More than 30 adverse events were significantly more common in the zoledronic acid group and were regarded collectively as constituting an APR. These were clustered into five groups: fever; musculoskeletal (pain and joint swelling); gastrointestinal (abdominal pain, vomiting, diarrhea); eye inflammation; and general (including fatigue, nasopharyngitis, edema). A total of 42.4% of the zoledronic acid group had an APR after the first infusion, compared with 11.7% of the placebo group. All APR components had their peak onset within 1 d, the median duration of the APR was 3 d, and severity was rated as mild or moderate in 90%. Stepwise regression showed that APR was more common in non-Japanese Asians, younger subjects, and nonsteroidal antiinflammatory drug users and was less common in smokers, patients with diabetes, previous users of oral bisphosphonates, and Latin Americans (P < 0.05 for all).

CONCLUSION

This analysis identifies new components of the APR and provides the first assessment of risk factors for it. Despite its frequency, APR rarely resulted in treatment discontinuation in this study.

Acute effects of intravenous administration of pamidronate in patients with osteoporosis

We investigated acute effects of intermittent large dose bisphosphonate therapy in osteoporotic patients. Peripheral blood mononuclear cells were incubated with alendronate (100 microM) for 18 hr, in vitro and cytokine expressions were measured by real-time RT-PCR. Pamidronate 30 mg was administered on 26 osteoporotic patients; and acute phase reactants, inflammatory cytokines and bone biomarkers were measured. The in vitro study showed significant increase in mRNA expression of IL-6, TNF-alpha and IFN-gamma. A notable rise in serum C-reactive protein (CRP) was observed over 3 days after pamidronate infusion (P=0.026). Serum levels of TNF-alpha, IL-6 and IFN-gamma were also significantly increased (P=0.009, 0.014, 0.035, respectively) and the increase in IL-6 levels were strongly correlated with CRP levels (P=0.04). Serum calcium and c-telopeptide levels rapidly decreased after the treatment (P=0.02, <0.001, respectively). This study showed that mRNA expression of inflammatory cytokines at peripheral blood mononuclear cells (PBMC) level were observed within 18 hr and marked elevation of inflammatory cytokines and acute phase reactants were demonstrated after pamidronate infusion at the dose for osteoporosis. Our studies confirmed that intermittent large dose aminobisphosphonate causes acute inflammation.

The effect of risedronate treatment on serum cytokines in postmenopausal osteoporosis: a 6-month randomized and controlled study

There is much evidence suggesting that the decline in ovarian function after menopause is associated with spontaneous increases in proinflammatory cytokines. Treatment with risedronate is accompanied by significant changes in bone turnover and bone mineral density. The objective of this study was to determine the effects of risedronate treatment on the level of serum cytokines including receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin among postmenopausal women with osteoporosis. The study group consisted of 61 postmenopausal women with osteoporosis. Patients were randomly divided in two groups: In group 1 (n = 41) postmenopausal women received oral risedronate (35 mg/week), calcium (1,000 mg/day), and vitamin D (400 IU/day) for 12 months. In group 2 (control group; n = 20) patients received only oral calcium (1,000 mg/day) and vitamin D (400 IU/day). Bone mineral density (BMD) of lumbar spine (L1-L4) and proximal femur were determined using dual X-ray absorptiometry at baseline and after one year. Venous blood samples were obtained for determination of serum cytokines including interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), RANKL, osteoprotegerin, and markers of bone formation and resorption. Levels of serum cytokines were measured before therapy and after three and 6 months. Markers of bone metabolism were studied before therapy and after 6 months. In group 1 (risedronate plus calcium/vitamin D-treated patients), serum levels of RANKL and IL-1beta significantly decreased and the level of osteoprotegerin significantly increased after three and 6 months, but no significant difference was found in TNF-alpha level. In group 2, however, the level of serum cytokines did not change after three and 6 months. In cases of bone turnover, both markers of bone resorption and formation significantly decreased after 6 months in group 1. In conclusion risedronate could improve osteoporosis by increasing osteoprotegerin and reducing RANKL and IL-1beta.

Statins prevent bisphosphonate-induced gamma,delta-T-cell proliferation and activation in vitro

The acute phase response is the major adverse effect of intravenously administered N-BPs. In this study we show that N-BPs cause gamma,delta-T-cell activation and proliferation in vitro by an indirect mechanism through inhibition of FPP synthase, an effect that can be overcome by inhibiting HMG-CoA reductase with a statin. These studies clarify the probable initial cause of the acute phase response to N-BP drugs and suggest a possible way of preventing this phenomenon.

INTRODUCTION

The acute phase response is the major adverse effect of intravenously administered nitrogen-containing bisphosphonate drugs (N-BPs), used in the treatment of metabolic bone diseases. This effect has recently been attributed to their action as non-peptide antigens and direct stimulation of gamma,delta-T-cells. However, because N-BPs are potent inhibitors of farnesyl diphosphate (FPP) synthase, they could cause indirect activation of gamma,delta-T-cells owing to the accumulation of intermediates upstream of FPP synthase in the mevalonate pathway, such as isopentenyl diphosphate/dimethylallyl diphosphate, which are known gamma,delta-T-cell agonists.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from healthy volunteers and treated with N-BP, statin, or intermediates/inhibitors of the mevalonate pathway for 7 days in the presence of interleukin (IL)-2. Flow cytometric analysis of the T-cell-gated population was used to quantify the proportion of gamma,delta-T-cells in the CD3+ population.

RESULTS AND CONCLUSIONS

The ability of N-BPs to stimulate proliferation of CD3+ gamma,delta-T-cells in human PBMC cultures matched the ability to inhibit FPP synthase. Gamma,delta-T-cell proliferation and activation (interferon gamma [IFNgamma] and TNFalpha release) was prevented by mevastatin or lovastatin, which inhibit HMG-CoA reductase upstream of FPP synthase and prevent the synthesis of isopentenyl diphosphate/dimethylallyl diphosphate. Desoxolovastatin, an analog of lovastatin incapable of inhibiting HMG-CoA reductase, did not overcome the stimulatory effect of N-BP. Furthermore, statins did not prevent the activation of gamma,delta-T-cells by a synthetic gamma,delta-T-cell agonist or by anti-CD3 antibody. Together, these observations show that N-BPs indirectly stimulate the proliferation and activation of gamma,delta-T-cells caused by inhibition of FPP synthase and intracellular accumulation of isopentenyl diphosphate/ dimethylallyl diphosphate in PBMCs. Because activation of gamma,delta-T-cells could be the initiating event in the acute phase response to bisphosphonate therapy, co-administration of a statin could be an effective approach to prevent this adverse effect.

New therapies for ankylosing spondylitis: etanercept, thalidomide, and pamidronate

Ankylosing spondylitis (AS) is the most common of a group of diseases called seronegative spondyloarthropathies. This group of diseases shares common demographic, clinical, and genetic features. This article reviews the rationale, clinical efficacy, and safety reports of etanercept, thalidomide, and pamidronate in the treatment of patients who have AS.

Daily oral pamidronate in women and men with osteoporosis: a 3-year randomized placebo-controlled clinical trial with a 2-year open extension

The efficacy and safety of oral pamidronate was examined in a double-blind, placebo-controlled trial in women and men with established osteoporosis. Seventy-eight postmenopausal women and 23 men with at least one prevalent vertebral fracture were randomized separately to 150 mg/day of pamidronate or placebo for 3 years followed by 150 mg/day of pamidronate for an additional 2 years. In addition, all patients received 400 U/day of cholecalciferol and 500 mg/day of elemental calcium. Pamidronate increased significantly bone mineral density of the lumbar spine (LS-BMD) and of the femoral neck (FN-BMD). The total increase in BMD of the spine after 5 years of treatment was 14.3%. Lateral spine radiographs were obtained at baseline and after 3 years of treatment. Fractures of previously normal vertebrae occurred in 15 of 45 patients treated with placebo (33.3%) and in 5 of 46 patients treated with pamidronate (11%). The relative risk was 0.33 (95% CI, 0.14-0.77). Treatment was well tolerated and there was no difference in gastrointestinal toxicity between pamidronate and placebo-treated patients. One hundred fifty milligrams daily of pamidronate is an effective and safe treatment of women and men with established osteoporosis.

The clinical and cost considerations of bisphosphonates in preventing bone complications in patients with metastatic breast cancer or multiple myeloma

The bisphosphonates are potent inhibitors of osteoclast-mediated bone resorption and are now the treatment of choice for the management of hypercalcaemia of malignancy. The incidences of hypercalcaemia and other skeletal complications (bone pain, pathological fracture) remain high despite apparent responses to systemic therapy, with particularly high event rates in women with advanced skeletal metastases of breast cancer. This review focuses on studies addressing the long-term efficacy of bisphosphonates to reduce skeletal complications in breast cancer (5 studies) and multiple myeloma (4 studies), with particular reference to controlled studies of sufficient magnitude and duration to allow confidence in the estimation of efficacy. Bearing in mind the limitations of differences in trial design and the lack of direct studies comparing drugs, adequate exposure to a bisphosphonate reduces the incidence of skeletal complication by 30 to 40% in both breast cancer and multiple myeloma. Oral clondronate and intravenous pamidronate have similar efficacy in both diseases, but the duration of efficacy may differ between drugs. Both agents have shown intriguing survival benefits in subgroups of patients. The numbers needed to treat (NNT) to prevent a skeletal complication during one year are lowest in metastatic skeletal disease in breast cancer (NNT < 8) but also compare very favourably with other disease for patients with recurrent nonskeletal breast cancer or multiple myeloma (NNTs 7 to 31 depending on the complication to be prevented). Treatment costs of both breast cancer and multiple myloma are driven by inpatient and outpatient hospital visits so that bisphosphonate regimens should be developed that reduce both. Further research is required to determine if subgroups of patients can be better identified that will derive particular benefit, or perhaps no benefit at all, from bisphosphonate therapy. It is not known whether more potent bisphosphonates will deliver greater clinical efficacy in the future.

Acute effects of etidronate on glucocorticoid-induced bone degradation

OBJECTIVES

To study the acute short-term effects on the biochemical parameters of calcium and bone homeostasis in post-menopausal women treated with a high dose of prednisone alone or with additional etidronate, before and during 5 days of treatment.

METHODS

Serum calcium, phosphorus, creatinine, alkaline phosphatase activity, osteocalcin, carboxy-terminal propeptide of type I procollagen (PICP), cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), parathyroid hormone (PTH), 25-hydroxyvitamin D and urinary excretion of calcium over 24 h were measured before and during 5 days of treatment in 14 post-menopausal women treated with a high dose of prednisone (60 mg/day) alone (group A) or combined with cyclical etidronate (group B).

RESULTS

Significant differences from baseline were found in osteocalcin and urinary excretion of calcium in both groups and for ICTP in group B. Significant differences between groups were calculated at day 5 of the study for osteocalcin, ICTP and 24 h urine calcium excretion (P < 0.01). Urinary excretion of calcium over 24 h increased in group A (+14.7%; P < 0.05) and decreased in group B (-22.1%; P < 0.01). Osteocalcin levels decreased in group A (- 38.1%) and increased in group B (+27.4%; both P < 0.01). ICTP decreased only in group B (-19.4%; P < 0.01).

CONCLUSIONS

The results are consistent with the fact that etidronate is acutely able to prevent bone resorption due to corticosteroids. The increase in osteocalcin in the etidronate-treated group is a new feature. A direct or indirect (PTH, 1,25 vitamin D?) stimulatory effect of etidronate on the osteoblast cannot be excluded.

Pro-inflammatory effects of the aminobisphosphonate ibandronate in vitro and in vivo

OBJECTIVES

To investigate the effects of the aminobisphosphonate, ibandronate, on the course of joint inflammation in rat antigen-induced arthritis (AIA) and the release of pro-inflammatory cytokines in partially purified human peripheral blood mononuclear cells (PBMC).

METHODS

Rats with AIA received a single intra-articular injection of ibandronate (1 mg) 7 days post-arthritis induction and knee swelling was measured for 7 days thereafter. The effects of ibandronate (300 microg/ml) on PBMC cytokine production and activation marker expression were determined using polymerase chain reaction (PCR)/ELISA and FACS analysis, respectively.

RESULTS

Joint swelling, associated with AIA, was sustained in ibandronate-treated rats compared with saline-treated control rats. Ibandronate stimulated the production of interferon gamma (IFN-gamma) in adherent PBMC, and increased the surface expression of FcgammaRI and HLA DP, DQ, DR on the adherent monocyte population. Activation by lipopolysaccharide (LPS) of PBMC previously incubated with ibandronate led to enhanced levels of tumour necrosis factor alpha (TNF-alpha) secretion, and this could be partially inhibited by neutralizing antibodies to IFN-gamma.

CONCLUSIONS

The enhanced production of TNF-alpha by ibandronate-treated PBMC in vitro involves stimulation of adherent monocytes by IFN-gamma prior to LPS-induced activation. Similar cellular interactions may be involved in the pro-inflammatory effects of ibandronate in vivo.

A randomized, double-blind comparison of risedronate and etidronate in the treatment of Paget's disease of bone. Paget's Risedronate/Etidronate Study Group

PURPOSE

To compare the efficacy and tolerability of oral risedronate and etidronate for treatment of Paget's disease of bone.

PATIENTS AND METHODS

Patients from 12 centers in North America received risedronate 30 mg daily for 2 months (62 patients) or etidronate 400 mg daily for 6 months (61 patients) in a prospective, randomized, double-blind study. Serum alkaline phosphatase (the primary variable), serum bone-specific alkaline phosphatase, and urinary deoxypyridinoline concentrations were monitored for 12 to 18 months.

RESULTS

Serum alkaline phosphatase concentration normalized by month 12 in 73% of risedronate-treated patients, compared with 15% of those receiving etidronate (P <0.001). Median time to normalization was 91 days for risedronate-treated patients and >360 days for etidronate-treated patients (P <0.001); relapse rates were 3% in the risedronate group and 15% in the etidronate group (P <0.05). At month 18, 53% of the risedronate group and 14% of the etidronate group remained in biochemical remission. Urinary deoxypyridinoline normalized in 87% of patients on risedronate and 57% of patients receiving etidronate (P <0.01); serum bone-specific alkaline phosphatase normalized in 73% of patients on risedronate and 18% of patients on etidronate (P <0.001). Patients who had received etidronate previously had a blunted response to etidronate, but not to risedronate. Reductions in pain were statistically significant in the risedronate group, but not in the etidronate group. Both drugs were well tolerated.

CONCLUSION

Although etidronate is effective, risedronate offers a shorter duration of therapy, better and longer-lasting remission, significant reductions in pain, and provides additional remission in subjects who exhibited an incomplete response to previous etidronate treatment.

Bisphosphonates in bone diseases

Bisphosphonates are a class of drugs which are strongly attracted to the bone where they influence the calcium metabolism, mainly by inhibition of the osteoclast-mediated bone resorption. This property makes these compounds suited for the treatment of several diseases of the bone. In Paget's disease, several bisphosphonates can reduce bone pain and decrease the bone turnover 60-70%. Cyclical oral etidronate and daily oral alendronate both proved to reduce the vertebral fracture rate for postmenopausal osteoporotic woman, while most investigated bisphosphonates can increase spinal bone mass in osteoporosis. Bisphosphonates can help lowering serum calcium and reverse skeletal complications in malignancy mediated bone diseases. Oral and intravenous administration of therapeutic doses is relatively safe. In general, gastrointestinal disturbances are described most often and the oldest, least potent, bisphosphonate etidronate can induce osteomalacia. The various characteristics of bisphosphonates: physicochemical, biological, therapeutic and toxicological, vary greatly depending on the structure of the individual bisphosphonate. Even small changes in the structure can lead to enormous differences in potency. Overall, this class of drugs offers several prospects for the future.

Alendronate/interleukin-1beta cotreatment increases interleukin-6 in bone and UMR-106 cells: dose dependence and relationship to the antiresorptive effect of alendronate

Aminobisphosphonates inhibit bone resorption but have been shown to elicit acute-phase-like elevations in interleukin-6 (IL-6) in bone in vitro. The current studies were carried out to determine the relationship between the antiresorptive effects of the aminobisphosphonate alendronate and its effects on IL-6. Resorption was elicited in cultured 19-day fetal rat limb bones by 72 h treatment with interleukin-1beta (IL-1beta). Bone mass was quantitated at the end of the culture period to assess resorption. IL-6 was determined by bioassay (7TD1 cell proliferation). IL-1beta (18 and 180 pM) stimulated bone resorption and increased IL-6. Alendronate (70 microM) inhibited the IL-1beta-stimulated resorption. Alendronate alone did not affect IL-6 production by the bones. The IL-6 production from bones stimulated with 18 pM IL-1beta was not significantly affected by alendronate, but the IL-6 production from bones stimulated with 180 pM IL-1beta plus alendronate (21 and 70 microM) was higher than with IL-1beta alone. Indomethacin (1 mM) inhibited the IL-6 increase elicited by 180 pM IL-1beta and the enhanced IL-6 production elicited by cotreatment with IL-1beta and alendronate. Since bone cultures contain multiple cell types, further experiments were carried out to determine whether alendronate could increase IL-1beta-stimulated IL-6 production in an osteoblast cell line, UMR-106. Alendronate alone did not affect IL-6 in UMR-106 cells. Alendronate (70 microM) in combination with IL-1beta (180, 1.8, or 8 nM), or 7 microM alendronate, in combination with 8 nM IL-1beta, significantly increased IL-6 in 48 h cell cultures. The results from the bone organ cultures show that alendronate can enhance IL-6 production elicited by higher concentrations of the cytokine IL-1beta in bone, but that this effect on IL-6 does not prevent the inhibitory actions of alendronate on bone resorption. The results with the UMR106 cells indicate that one cellular site at which this enhancement of IL-6 production can occur is the osteoblast.

Modification of serum apolipoprotein A-I, apolipoprotein B and lipoprotein(a) levels after bisphosphonates-induced acute phase response

Lipoprotein(a) (Lp(a)) is a low density lipoprotein-like particle displaying strong atherothrombotic properties. Although the concentration of Lp(a) in plasma is under strong genetic regulation, there are emerging evidences that several other factors, such as hormonal disorders, acute phase, liver and renal failure may affect its metabolism. The aim of the present study was to investigate whether bisphosphonates, an effectual drug in the treatment of malignant hypercalcemia and Paget's disease of bone, known to induce a concomitant acute phase, may have a significant influence on Lp(a) concentrations. Nine subjects (four men and five women), with plasma Lp(a) concentrations in the range between 6.4 and 17.7 mg/dl, were subjected to a single intravenous infusion of bisphosphonates (7.5 mg of aminohydroxybutylidene and 5.0 mg of aminohydroxylidene), previously dissolved in 250 ml of saline. Lp(a), apo A-I, apo B, C reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured at the baseline and after days one, two, four and seven. CRP, ESR and Lp(a) started to increase after two days from the treatment, reaching statistical significance after day two, four and seven, respectively. Apo B and apo A-I decreased significantly after days one and two, respectively. Although patterns and relative amounts of the increase of CRP were substantially different among the subjects studied, the increase of Lp(a) was more homogeneous; the peak of Lp(a) concentrations was reached only seven days after treatment in the group as a whole, in agreement with previous observations. In univariate regression analysis, significant correlations were found only between apo A-I and ESR, and apo A-I and Lp(a). The present study suggest that Lp(a) behaves as an acute phase protein. Besides, we observed a slight but significant decrease of apo A-I and apo B after administration of bisphosphonates.

Clodronate and liposome-encapsulated clodronate are metabolized to a toxic ATP analog, adenosine 5'-(beta, gamma-dichloromethylene) triphosphate, by mammalian cells in vitro

Clodronate, alendronate, and other bisphosphonates are widely used in the treatment of bone diseases characterized by excessive osteoclastic bone resorption. The exact mechanisms of action of bisphosphonates have not been identified but may involve a toxic effect on mature osteoclasts due to the induction of apoptosis. Clodronate encapsulated in liposomes is also toxic to macrophages in vivo and may therefore be of use in the treatment of inflammatory diseases. It is generally believed that bisphosphonates are not metabolized. However, we have found that mammalian cells in vitro (murine J774 macrophage-like cells and human MG63 osteosarcoma cells) can metabolize clodronate (dichloromethylenebisphosphonate) to a nonhydrolyzable adenosine triphosphate (ATP) analog, adenosine 5'-(beta, gamma-dichloromethylene) triphosphate, which could be detected in cell extracts by using fast protein liquid chromatography. J774 cells could also metabolize liposome-encapsulated clodronate to the same ATP analog. Liposome-encapsulated adenosine 5'-(beta, gamma-dichloromethylene) triphosphate was more potent than liposome-encapsulated clodronate at reducing the viability of cultures of J774 cells and caused both necrotic and apoptotic cell death. Neither alendronate nor liposome-encapsulated alendronate were metabolized. These results demonstrate that the toxic effect of clodronate on J774 macrophages, and probably on osteoclasts, is due to the metabolism of clodronate to a nonhydrolyzable ATP analog. Alendronate appears to act by a different mechanism.

Bisphosphonates induce apoptosis in mouse macrophage-like cells in vitro by a nitric oxide-independent mechanism

Bisphosphonates (BPs) are an important class of antiresorptive drugs used in the treatment of bone diseases, including osteoporosis. Although their mechanism of action has not been identified at the molecular level, there is substantial evidence that BPs can have a direct effect on osteoclasts by mechanisms that may lead to osteoclast cell death by apoptosis. BPs can also inhibit proliferation and cause cell death in macrophages in vitro. We have now shown that the toxic effect of BPs on macrophages is also due to the induction of apoptotic, rather than necrotic, cell death. Morphological and biochemical features that are definitive of apoptosis (chromatin condensation, nuclear fragmentation, and endonuclease-mediated internucleosomal cleavage of DNA) could be identified in mouse macrophage-like J774 and RAW264 cells, following treatment with 100 microM pamidronate, alendronate, and ibandronate for 24 h or more. Clodronate was much less potent, even at 2000 microM, while 2000 microM etidronate did not cause apoptosis. Apoptosis was not due to increased synthesis of nitric oxide and could not be prevented by inhibitors of nitric oxide synthases. Since macrophages, like osteoclasts, are particularly susceptible to BPs, these observations support the recent suggestion that the mechanism by which BPs inhibit bone resorption may involve osteoclast apoptosis. Furthermore, the macrophage-like cell lines used in this study may be a convenient model with which to identify the molecular mechanisms by which BPs promote apoptosis in osteoclasts. Induction of macrophage apoptosis by BPs in vivo may also account, at least in part, for the anti-inflammatory properties of BPs as well as the ability of BPs to cause an acute phase response.

Clinical, biochemical, hematologic, and radiographic responses in Paget's disease following intravenous pamidronate disodium: a 2-year study

An intravenous dosage schedule using pamidronate disodium, based on biochemical severity, was used to treat 71 patients with Paget's disease who had no previous bisphosphonate treatment. Disease severity was stratified by fasting hydroxyproline excretion (HypE): Group (Gp) I (mild disease; HypE < 5.0 mumol/LGF) received a total dose of 120 mg; Gp II (moderate; HypE 5.00-9.99) received 180 mg; and Gp III (severe; HypE > or = 10) received 240 mg. Within each group patients were randomly allocated to receive daily 30 mg or 60 mg infusions. Observations for 2 years included pain scores, indices of bone turnover, and radiology of lytic lesions. There was no difference in biochemical responses, or in the percentage of patients with early fever, between the 30 mg and 60 mg daily subgroups; for convenience, 60 mg infusions are recommended. Neutrophils and total white cell counts were both significantly below baseline 4 days after the first infusion; lymphocytes were significantly reduced by day 2; and all three measures had returned to within the reference range by day 6. Remission was assessed at 6 months, when both plasma alkaline phosphatase (ALP) and HypE had reached stable nadirs. Increasing severity was associated with increasing resistance to suppression of HypE at 6 months to within the reference range: Gp I, 87%; Gp II, 44%; and Gp III, 0% (p < 0.0001 by chi-square test). Biochemical relapse at 2 years (defined as ALP 50% above the 6 month level) was also dependent on initial disease severity (Gp I, 6%; GpII, 39%; Gp III, 62%; p < 0.0005 by chi-square test). There was no association between time to relapse and either initial dose or log dose. Radiologic lytic lesions (in 22 patients) were all in remission at 3 months; however, relapse rates at 2 years appeared to be severity-dependent: Gp I, 13%; Gp II, 43%; and Gp III, 57% (n.s. by chi-square test). Remission rates based on a fall to < 50% of pretreatment of either HypE or ALP were more in accord with lytic lesion remission rates than were rates based on HypE falling to within the reference range. Pamidronate produced a significant reduction from baseline in Pagetic bone, Pagetic joint, and unrelated musculoskeletal pain in the first 6 months (p < 0.0001). From 0 months to 2 years the maintenance of improvement in bone pain (p < 0.005) and joint pain (p < 0.05) was significantly better than in unrelated pain. Pamidronate is a safe, welltolerated, and effective treatment for Paget's disease. In spite of larger dosage in severe disease, increasing severity was associated with resistance to normalization of biochemistry and a higher incidence of biochemical and radiological relapse at 2 years. Our current dosage recommendation would be for two 60 mg infusions for mild disease (Gp I); and four 60 mg infusions for moderate disease (Gp II). Severe disease (Gp III) remains a challenge; regardless of dosage, the majority of patients will be in relapse 2 years after a single course of treatment.

Contrast between effects of aminobisphosphonates and non-aminobisphosphonates on collagen-induced arthritis in mice

1. Bisphosphonates (BPs) are inhibitors of bone resorption, and many derivatives have been developed for the treatment of enhanced bone resorption. Aminobisphosphonates (aminoBPs) are particularly potent in this respect. We have shown previously that aminoBPs, such as 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid (AHBuBP), induce histidine decarboxylase, the enzyme forming histamine, and increase macrophages, granulocytes and osteoclast numbers. Non-aminoBPs do not show this activity. 2. In the present study, an additional aminoBP, cycloheptyl-aminomethylene bisphosphonate (CHAMBP), was shown to have similar properties to AHBuBP suggesting that these actions are common among aminoBPs. 3. In experiments carried out to determine if aminoBPs affect immune responses, we found that CHAMBP and AHBuBP each exacerbated the arthritis induced in mice by the co-injection of type II collagen and an adjuvant, a model for rheumatoid arthritis. In contrast, dichloromethylene bisphosphonate (C12MBP), a typical non-aminoBP, did suppress the arthritis. 4. On the basis of these results, and those obtained previously, we propose that the exacerbating effects of CHAMBP and AHBuBP may be related to their ability to stimulate the synthesis of histamine and to increase macrophages and granulocytes. Conversely, we propose that the suppressive effect of C12MBP on arthritis is related to its cytotoxic action on macrophages or granulocytes.

Increased bone mass with pamidronate treatment in rheumatoid arthritis. Results of a three-year randomized, double-blind trial

OBJECTIVES

Osteoporosis is a frequent complication of rheumatoid arthritis (RA). We therefore investigated the effect of oral pamidronate therapy as a specific bone-sparing agent in RA.

METHODS

The study design was a 3-year randomized, double-blind trial of 300 mg oral pamidronate/day compared with placebo in 105 RA patients. Bone mineral density (BMD) measured at 12-month intervals was the primary efficacy parameter.

RESULTS

In 3 years, lumbar spine and forearm BMD increased significantly in the pamidronate-treated group (by 8.4 +/- 6.9% [mean =/- SEMI] [P < 0.00011 and 5.2 =/- 6.5% [P < 0.005], respectively), compared with nonsignificant changes in the placebo-treated patients (increase of 0.6 =/- 5.2% and decrease of 1.2 =/- 5.8%, respectively). Femoral neck BMD increased in the pamidronate-treated group (by 2.6 =/- 8.6%) and decreased significantly in the placebo-treated group (by 4.0=/- 1.3% [P < 0.005]). The changes in BMD with time at all 3 measurement sites were significantly different between the treatment groups (P < 0.0001). Changes in radiographic signs of joint damage and in disease activity were similar in the 2 groups.

CONCLUSION

The present study provides the first evidence that long-term treatment with an orally administered bisphosphonate overcomes bone loss and increases bone mass when compared with placebo. This finding may have significance with regard to the treatment of patients with RA.

Interleukin-6 and tumor necrosis factor alpha levels after bisphosphonates treatment in vitro and in patients with malignancy

Bisphosphonates are potent inhibitors of bone resorption and are widely used in the treatment of bone diseases. One of the side effects of administered aminobisphosphonates is transient fever and some biological changes that are suggestive of an acute phase response. Pamidronate [(3-amino-1-hydroxypropylidene).1, 1-bisphosphonate] and ibandronate [1-hydroxy-3-(methylpentylamino) propylidenebisphosphonate] incubated in heparinized whole blood at doses of 10(-4) and 10(-5) mol/L, induced the production of tumor necrosis factor alpha (TNFalpha). Moreover, pamidronate was found to slightly stimulate interleukin-6 IL-6 production. In contrast, clodronate (dichloromethylenebisphosphonate) did not increase IL-6 or TNFalpha. To investigate these phenomena in vivo, acute phase reaction was assessed in patients with malignant disease treated with 60 mg of pamidronate (n = 29), 1500 mg of clodronate (n = 8), or 0.5-2 mg of ibandronate (n = 6), all given intravenously. A significant decrease in lymphocyte and leukocyte count was observed in the pamidronate group. In the same group, seven patients (24%) showed a transient increase of body temperature above 37 degrees C with an increase > or = 0.5 degrees C at 24 h. These changes were not found in the patients treated with clodronate or ibandronate. Plasma IL-6 and TNFalpha levels increased significantly after pamidronate treatment, whereas no change was seen after clodronate infusion. The peak of IL-6 level (53.7 +/- 14.1 [SEM] pg/mL) was observed at 24 h, and that of TNFalpha level (26.9 +/- 3.4 pg/mL) at 48 h after the beginning of pamidronate administration (values before treatment, respectively: 28.6 +/- 7.1 pg/mL, p < 0.006; and 13.1 +/- 1.5 pg/mL, p = 0.0001). The peak of C-reactive protein (CRP) level was found at 48 h (41.0 +/- 7.8 vs. 25.5 +/- 5.6 mg/L before treatment, p < 0.01) and CRP levels were strongly correlated with IL-6 levels (p = 0.65,p < 0.001). Only one patient treated with ibandronate showed an increase in IL-6 and CRP levels. Patients treated with pamidronate, whose body temperatures were increased at 24 h, had a greater increases of circulating IL-6, TNFalpha, and CRP at 24 h and 48 h than patients without temperature increase. These results suggest that pamidronate treatment, but not clodronate and possibly not ibandronate at the doses used, induced an increase in the plasma levels of IL-6 and TNFalpha, which may be responsible for the acute phase reaction observed clinically.

Bisphosphonates: a review of their pharmacokinetic properties

Bisphosphonates are a unique class of drugs. As a family, they are characterized pharmacologically by their ability to inhibit bone resorption, whereas, pharmacokinetically, they are classified by their similarity in absorption, distribution, and elimination. Although all bisphosphonates have similar physicochemical properties, their antiresorbing activities differ substantially. Activity is dramatically increased when the amino group is contained in the aliphatic carbon chain. For example, alendronate, an aminobisphosphonate, is approximately 700-fold more potent than etidronate, both in vitro and in vivo. In general, bisphosphonates are poorly absorbed from the gastrointestinal tract as a result of their poor lipophilicity. In vitro and in vivo studies have shown that bisphosphonates are absorbed from the gastrointestinal tract via paracellular transport. Systemically available bisphosphonates disappear very rapidly from plasma, and are partly taken up by the bone and partly excreted by the kidney. The relative contribution of these two processes to overall plasma elimination differs significantly among bisphosphonates. To date, all bisphosphonates studied show no evidence of metabolism. Renal excretion is the only route of elimination. Studies with alendronate in rats indicate that the drug is actively secreted by an uncharacterized renal transport system, and not by the anionic or cationic renal transport systems. Bisphosphonates bind preferentially to bones which have high turnover rates, and their distribution in bone is not homogeneous. After bone uptake, the bisphosphonates are liberated again only when the bone in which they are deposited is resorbed. Thus, the half-life of bisphosphonates in bone is very long, ranging among different species from 1 to 10 years, depending largely on the rate of bone turnover.

Interleukin-6 and the acute phase response during treatment of patients with Paget's disease with the nitrogen-containing bisphosphonate dimethylaminohydroxypropylidene bisphosphonate

Bisphosphonates suppress bone resorption and are used in the management of bone diseases with increasing frequency. In some patients treated for the first time with potent nitrogen-containing bisphosphonates, there is a transient febrile reaction and transient hematological changes suggestive of an acute phase response. Because IL-6 is considered to be an important mediator of the acute phase response, we examined the changes in circulating IL-6 bioactivity in 38 patients with Paget's disease treated with the nitrogen-containing bisphosphonate (3-dimethyl-amino-1-hydroxypropylidene)-1,1-bisphosphonate (dimethyl-APD). 16 patients who had never received such bisphosphonate were treated with oral dimethyl-APD (100-400 mg/day) and 22 (9 for the first time) with intravenous dimethyl-APD 4 mg/day. Treatment was given for 10 days. Eleven of 38 patients, all first treatments, showed an increase in body temperature of more than 0.5 degrees C exceeding 37 degrees C associated with a significant decrease in lymphocyte count and an increase in serum CRP values. These changes were transient and did not occur in the patients with no febrile response. In patients with a febrile reaction circulating IL-6 bioactivity increased significantly and this increase generally preceeded the rise in temperature. Moreover, patients with an acute phase response had significantly higher peak IL-6 values than those without (128 +/- 30 vs. 31 +/- 4 U/ml, p < 0.001). The peaks in plasma IL-6 were further correlated with the peaks in temperature and in serum CRP values (r = 0.49, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Pamidronate disodium and possible ocular adverse drug reactions

Ciba-Geigy Central Epidemiology and Drug Safety Center has received 23 reports of suspected ocular adverse drug reactions associated with the use of intravenous pamidronate disodium, an inhibitor of bone resorption that is used primarily in the management of tumor-induced hypercalcemia and Paget's disease of the bone. Anterior uveitis, bilateral in six of seven patients, occurred within 24 to 48 hours after the drug was administered. The anterior uveitis recurred in four of the five patients who were rechallenged. Three reports involved unilateral episcleritis or scleritis occurring within one to six days after the administration of the drug. Only the episcleritis patient was rechallenged five months later, when the patient again had the episcleritis occur in the same eye. Thirteen patients reported nonspecific transitory conjunctivitis within six to 48 hours after pamidronate disodium was given intravenously. This was positive on rechallenge in six of eight patients. These data indicate that, on rare occasions, pamidronate disodium is a probable cause of anterior uveitis or nonspecific transitory conjunctivitis and is a possible cause of episcleritis or scleritis.

Significance of plasma PTH-rp in patients with hypercalcemia of malignancy treated with bisphosphonate

BACKGROUND

Hypercalcemia of malignancy (HM) is one of the commonest metabolic complications associated with cancer. Plasma parathyroid hormone-related peptide (PTH-rp) is known to cause hypercalcemia in the vast majority of patients with HM.

METHODS

Fifty-two patients with HM were treated with a single infusion of 60 mg of pamidronate (3-amino-1-hydroxypropylidene-1, 1-bisphosphonate). Serum calcium and plasma PTH-rp levels were measured at the basal and after pamidronate therapy.

RESULTS

Normocalcemia was achieved in 43 (i.e., 83%) of these patients within 3 to 5 days. Eighty-one percent had increased plasma PTH-rp levels. There was no difference in the percentages of patients who had elevated plasma PTH-rp levels compared with those of patients with metastatic bone disease and humoral HM. However, the latter group of patients had significantly higher circulatory PTH-rp levels (P < 0.01). The pretreatment calcium levels were not correlated with the calcium-lowering responses nor with plasma PTH-rp levels. However, there was a significant positive correlation between pretreatment plasma PTH-rp levels and the nadir serum calcium (P < 0.001) and a negative correlation with the changes in serum calcium levels (P < 0.001) after pamidronate therapy. No relationship existed between pretreatment calcium levels or PTH-rp levels with the extent or the severity of the metastatic bone disease. Patients who had the highest PTH-rp levels had the worst prognosis, poorest calcium-lowering effect, shortest duration of normocalcemia, and required higher doses and frequent infusions of pamidronate to maintain normocalcemia. The nonresponders to therapy had a significantly higher mean plasma PTH-rp level (> 75 pg/ml) than the responders (P < 0.01).

CONCLUSIONS

The plasma PTH-rp levels may help to predict the calcium-lowering effect of bisphosphonate and give an indication of the prognosis in patients with HM. They may allow identification of patients who need higher doses and increased frequency of administration of bisphosphonate, thereby expediting the normocalcemic response.

Paget's disease of bone: five regimens of pamidronate treatment

The efficacy of five therapeutic regimens using (3-amino-1-hydroxypropylidene)-1,1- bisphosphonate (APD or pamidronate) was assessed in patients with Paget's disease of bone. These regimens were as follows: (a) pamidronate 600 mg/day given orally during six months; (b) iv infusion of 20 mg daily for 10 days; (c) iv infusion of 40 mg daily for 5 days; (d) iv infusion of 10 mg daily for 4 days and (e) a single iv infusion of 10 mg. Six months after the initiation of therapy, urinary excretion of hydroxyproline and serum alkaline phosphatase activity (expressed as percent of their initial value) were: Group a: 30 +/- 10 (mean +/- SE) and 30 +/- 6, Group b: 55 +/- 8 and 46 +/- 6, Group c: 54 +/- 7 and 57 +/- 6, Group d: 53 +/- 7 and 69 +/- 4, and Group e: 85 +/- 10 and 98 +/- 4 respectively. Oral route was accompanied by digestive intolerance. On the contrary, except for rare and transient "flu-like syndromes", the iv treatment was not associated with any serious secondary effect. Intravenous infusion of pamidronate, 20 mg for 10 days or 40 mg for 5 days, appears as an interesting alternative to the oral route in the treatment of Paget's disease of bone.

Double blind radiological assessment of continuous oral pamidronic acid in patients with rheumatoid arthritis

Continuous oral pamidronate (APD), 1000 mg/day, was administered to 14 patients with rheumatoid arthritis. A control group of 13 patients with similar conditions received placebo under a double blind randomized study design. Periarticular erosion scores were significantly higher in the control group after 12 months treatment. This was attributed to a deterioration in this group rather than to an improvement in the APD treated one. By contrast, intraarticular narrowing score was not influenced by APD. Tolerance to oral APD was acceptable in all patients.

Pamidronate is effective for Paget's disease of bone refractory to conventional therapy

Paget's disease of bone is characterized by primary osteoclastic dysfunction and prolonged treatment with conventional medications including calcitonin and etidronate, results in a number of patients becoming refractory to treatment. We have evaluated the effectiveness of three dosage regimes of aminohydroxypropylidene bisphosphonate (pamidronate) in 15 patients with extensive Paget's disease who had become refractory to conventional therapy. Nine patients had pamidronate (intravenous infusion of 30 mg over 4-5 hours at monthly intervals) for 6 months. A further four patients received 30 mg of pamidronate infusion daily for 6 consecutive days and another two patients, 60 mg on 3 consecutive days (total dose of 180 mg/patient). In all three groups the bone-specific alkaline phosphatase and urinary hydroxyproline excretion both fell by 75% (P < 0.001). All but one patient showed a marked improvement in clinical symptomatology (pain and mobility) and biochemical parameters indicating decreased bone turnover. Remissions achieved (> 12 months) with all three regimens were comparable. The pagetic bone pain was reduced and the mobility was significantly improved after 3 months of therapy and was continued for up to 1 year. Currently, it may be difficult to justify the use of intravenous bisphosphonate as the first line of therapy for Paget's disease, but it does seem to have a definite place in patients with severe Paget's disease who do not respond to other therapeutic agents. Here we demonstrate that pamidronate is highly effective in patients with extensive Paget's disease who became refractory to conventional treatment. Further studies are necessary to optimize the dosage and frequency of administration of pamidronate.

Methylpentylaminopropylidenebisphosphonate (BM 21.0955): a new potent and safe bisphosphonate for the treatment of cancer-associated hypercalcemia

Bisphosphonates have been shown to be effective in lowering serum calcium levels in patients with cancer-associated hypercalcemia. 1-Hydroxy-3-(methylpentylamino)propylidenebisphosphonate (BM 21.0955) was developed as a third generation bisphosphonate and has been recently proven effective in animals and in patients with Paget's disease or tumor osteolysis. Thirty-six patients with cancer-associated hypercalcemia were treated with increasing doses (0.2-2.0 mg) of BM 21.0955 by single i.v. infusion over 4 h in a phase I trial. Six patients were rejected from analysis due to concomitant treatment with other bisphosphonates or chemotherapy. After rehydration and infusion of BM 21.0955 the mean serum calcium levels fell significantly (P < 0.001), from 3.29 +/- 0.49 mmol/l to 3.04 +/- 0.44 mmol/l until day 2 and normalized on day 6 (2.66 +/- 0.33 mmol/l). Serum calcium was reduced in all patients and normalized in 16. No symptomatic hypocalcemia occurred. Mean serum creatinine decreased significantly (P < 0.01), from 1.25 +/- 0.58 mg/dl (day 0) to 1.05 +/- 0.37 mg/dl (day 6). The mean urinary calcium/creatinine concentration fell significantly (P < 0.001), from 1.90 +/- 1.16 mM/mM (day 0) to 0.37 +/- 0.34 mM/mM/l (day 6). There were no subjective drug-related side effects during or after the infusion. Thirteen patients had elevations of morning body temperature above 38 degrees C. This was due to confirmed infections in five patients and possibly drug- or tumor-related in the other eight. We conclude from these preliminary results that a single infusion of BM 21.0955 is an effective and safe way to treat cancer-associated hypercalcemia.

Osteoclast recruitment in mice is stimulated by (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate

Though some evidence suggests that bisphosphonates (BPs) act directly on osteoclasts to inhibit bone resorption, other evidence suggests that they inhibit the development of the osteoclast. We found an increase in osteoclast recruitment in 2-day-old mice given (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD). A threefold increase in 5-bromo-2'-deoxyuridine (BrdU)-labeled osteoclast nuclei was observed on mouse parietal bones 3 days after APD injection. This suggests that inhibition of osteoclast development is not an action of APD in mice of this age. The mechanism of the increased recruitment was investigated. As osteoclast progenitors were not detected on parietal bones in vitro, we looked for an increase in circulating monocytes to account for the recruitment. No such increase was found, but when 51Cr-labeled bone marrow was injected intraperitoneally into mice given APD there was an increase in accumulation of 51Cr in calvaria and in femur and tibia over controls. This increase did not occur when 51Cr-labeled erythrocytes or free 51Cr was injected. We conclude that APD causes increased recruitment of osteoclast precursors by increasing the avidity of bone for hematopoietically derived cells.

Corticosteroid induced osteoporosis in severe menstrual asthma. Steroid sparing drugs may be useful

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Effects of five daily 1 h infusions of alendronate in Paget's disease of bone

We report a randomized placebo-controlled double-blind study of amino-hydroxybutylidene bisphosphonate (alendronate), infused over 1 h, in 15 patients with Paget's disease of bone. Alendronate, 10 mg/day for 5 days, suppressed urinary hydroxyproline to 44.9 +/- 4.8% and serum alkaline phosphatase to 74.6 +/- 5.4% of their pretreatment values within 1 month of the start of treatment. Within 5 months of the start of treatment serum alkaline phosphatase fell to 47.9 +/- 6.3% of pretreatment values. These effects were associated with a decrease in serum calcium and phosphate and in urinary calcium excretion and with a rise in serum iPTH values. A transient fever was observed in 3 of 10 patients who received alendronate during the course of the infusions, and this was associated with a decrease in the total and differential white cell count. No adverse effects were noted on renal function as judged by glomerular filtration rate and indices of proximal and distal tubular function. This regimen may simplify the management of patients with Paget's disease of bone.

Bisphosphonates. Pharmacology and use in the treatment of tumour-induced hypercalcaemic and metastatic bone disease

The geminal bisphosphonates are a new class of drugs characterised by a P-C-P bond. Consequently, they are analogues of pyrophosphate, but are resistant to chemical and enzymatic hydrolysis. The bisphosphonates bind strongly to hydroxyapatite crystals and inhibit their formation and dissolution. This physicochemical effect leads in vivo to the prevention of soft tissue calcification and, in some instances, inhibition of normal calcification. The main effect is to inhibit bone resorption, but in contrast to the effect on mineralisation, the mechanism involved is cellular. These various effects vary greatly according to the structure of the individual bisphosphonate. The half-life of circulating bisphosphonates is very brief, in the order of minutes to hours. 20% to 50% of a given dose is taken up by the skeleton, the rest being excreted in the urine. The half-life in bone is far longer and depends upon the turnover rate of the skeleton itself. Bisphosphonates are very well tolerated; the relatively few adverse events that have been associated with their use are specific for each compound. Bisphosphonates have been used to treat various clinical conditions, namely ectopic calcification, ectopic bone formation, Paget's disease, osteoporosis and increased osteolysis of malignant origin. The three compounds commercially available for use in tumour-induced bone disease are in order of increasing potency, etidronate, clodronate and pamidronate. Most data have been obtained with the latter two agents. By inhibiting bone resorption, they correct hypercalcaemia and hypercalciuria, reduce pain, the occurrence of fractures, as well as the development of new osteolytic lesions, and in consequence improve the quality of life. In view of these actions, of their excellent tolerability and of the fact that they are active for relatively long periods, these compounds are, after rehydration, the drugs of choice in tumour-induced bone disease and an excellent auxiliary to the drugs used in oncology.