Oral alendronate induces progressive increases in bone mass of the spine, hip, and total body over 3 years in postmenopausal women with osteoporosis

Efficacy of different dosing schedules of etidronate for stress shielding after cementless total hip arthroplasty

Forty-four women who had undergone cementless total hip arthroplasty (THA) were selected for determination of the optimum dosage of etidronate in the treatment of stress shielding after surgery. Patients were 55-86 years of age. The patients were randomized into three groups. The control group (n = 17) was not treated with osteoactive drugs. The low-dose group (n = 12) and the high-dose group (n = 15) received 200 mg or 400 mg etidronate daily for 2 weeks, followed by 12 weeks of calcium supplementation of 500 mg/day. These patients received four cycles of therapy over 1 year postoperatively. Periprosthetic bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry at 3 weeks, 6 months, and 12 months. At 12 months, bone loss in the low-dose and high-dose groups was significantly lower compared with the control group in Gruen zones 1 and 7. There were additional significant differences with regard to bone loss between the control group and the high-dose group in zones 2, 4, and 6. Our data suggest that high dosages are more effective in reducing postoperative bone loss after cementless THA.

The Role of Calcium in Osteoporosis Drug Therapy

Great advances have been made in the field of osteoporosis treatment and prevention in recent years that have led to the availability of powerful new drugs. These drugs are viewed by patients and physicians as a major breakthrough in the management of osteoporosis. Unfortunately, this view has led many to ignore the importance of concurrent calcium supplementation to ensure the maximum benefit from these drugs, as evidenced by the recent decline in use of calcium supplements. As the majority of patients fail to consume the minimum recommended dietary intake of calcium, it is critical to recommend calcium supplements to raise total daily calcium intake to the levels needed to ensure maximum efficacy of osteoporosis treatments. Furthermore, osteoporosis drug labeling should be strengthened to encourage proper use of these drugs in combination with calcium supplements.

The influence of alendronate on bone formation after autogenous free bone grafting in rats

OBJECTIVE

This study was undertaken to investigate the influence of alendronate on bone formation after autogenous free bone grafting in rats.

STUDY DESIGN

Fifty-six male Wistar-Albino rats were divided into 3 groups: baseline, saline-treated, and alendronate-treated groups, and followed up at 2, 4, and 12 weeks. In the femur of the rats, autogenous free bone grafts 3 mm in diameter and 2 mm in length were harvested with a standard trephine bur. The bone defects 3 mm in diameter and 2 mm in length were created 5 mm from the donor sites. Each graft was placed in the bone defect and stabilized by perifemoral wiring. The alendronate-treated rats were administered 0.25 mg/kg alendronate subcutaneously daily. The saline-treated rats were given daily saline solution. Serum calcium, phosphate, parathyroid hormone, 1,25-dihydroxyvitamin D, bone alkaline phosphatase (BAP), osteocalcin, and urine calcium were measured. The changes in the number of osteoblasts bordering active bone formation surface and osteoid and lamellar bone formation were evaluated to measure anabolic bone activity.

RESULTS

Alendronate caused significant increase in serum osteocalcin and BAP levels biochemically and the number of osteoblasts histopathologically.

CONCLUSION

Alendronate may be considered among therapeutic options to improve bone formation process in different bone remodeling cases. Further detailed studies should be focused on dosage- and time-dependent effects of alendronate on bone formation.

Microdamage accumulation in the monkey vertebra does not occur when bone turnover is suppressed by 50% or less with estrogen or raloxifene

Long-term suppression of bone turnover with alendronate has previously been shown to increase the degree of mineralization and accumulation of microdamage in animal bones. In an effort to ascertain if other suppressors of bone resorption can also affect mineralization and microdamage accumulation, we evaluated bones from cynomolgus macaques treated with raloxifene or conjugated equine estrogens (CEE). Cynomolgus monkeys (Macaca fascicularis) were randomized, ovariectomized (except for Sham controls), and orally treated each day for 2 years with vehicle (Sham and Ovx controls), 1 mg/kg raloxifene (R1), 5 mg/kg raloxifene (R5), or 0.04 mg/kg CEE. The functional quality of the mineralized matrix was analyzed postnecropsy by biomechanical testing, histomorphometry, biochemistry, and nanoindentation. Failure testing of the whole vertebra showed no significant differences in vertebral strength among groups. Similarly, failure testing of a beam of pure bone that was machined from the femoral diaphysis also showed no differences in material strength (ultimate stress) between groups. Histomorphometry of the L2 centrum showed that Ovx tended to increase activation frequency relative to Sham controls. Estrogen (CEE) treatment for 2 years at about four times the clinical exposure tended to reduce activation frequency (Ac.f) by 41% compared to Ovx. Treatment with raloxifene at either approximately the clinical dose or five times higher nonsignificantly lowered Ac.f by 34% and 23%, respectively, relative to Ovx. Raloxifene had similar effects on serum osteocalcin, a biochemical measure of systemic bone turnover. Analysis of microcrack surface density in the cancellous bone of L3 showed a 40% reduction for Ovx relative to Sham. CEE microcrack surface density was not different than Sham whereas the R5 crack density was significantly less than Sham and CEE. R1 microcrack surface density was not significantly different from Sham or Ovx. No significant differences in crack length were observed among the groups. Hardness, which is a measure of the state of mineralization, and elastic modulus were measured for both trabecular bone on a micron scale by nanoindentation. No significant differences between groups were observed. In summary, differences in functional bone quality of the lumbar spine were not observed between Sham, Ovx, or treated monkeys. CEE increased microcracks from Ovx to Sham levels, whereas raloxifene had no effect on microdamage accumulation. We conclude that suppressing bone turnover by 40% or less offers protection against microdamage accumulation that could result in an increased risk of vertebral fracture.

Therapeutic effects of alendronate 35 mg once weekly and 5 mg once daily in Japanese patients with osteoporosis: a double-blind, randomized study

The efficacy and safety of treatment with oral alendronate (ALN) 35 mg once weekly for 52 weeks were compared with those of ALN 5 mg once daily in a double-blind, randomized, multicenter study of Japanese patients with involutional osteoporosis. The primary efficacy end point was the percent change from baseline in the lumbar spine (L1-L4) bone mineral density (BMD) after 52 weeks of treatment. In this study, 328 patients were randomized to ALN 5 mg once daily (160 patients) or ALN 35 mg once weekly (168 patients). The adjusted mean percent change from baseline in lumbar spine (L1-L4) BMD after 52 weeks of treatment was 5.8% and 6.4% in the once-daily group and the once-weekly group, respectively (both P < 0.001). The 95% confidence interval for the difference in spine BMD change between the two treatment groups was -0.31% to 1.48%, indicating that the two regimens were therapeutically equivalent, since the confidence interval fell entirely within the predefined equivalence criterion (+/-1.5%). The time course of the spine BMD increase was also similar for both regimens. Regarding total hip BMD, mean changes from baseline at 52 weeks were 2.8% and 3.0% in the once-daily group and the once-weekly group, respectively. In addition, the bone markers (urinary deoxypyridinoline, urinary type-I collagen N-telopeptides, and serum bone-specific alkaline phosphatase) were reduced to a similar level by either treatment throughout the treatment period. The tolerability and safety profiles were also similar between the treatment groups. Taken together, we conclude that the efficacy and safety of the ALN 35-mg once-weekly regimen are therapeutically equivalent to those of the ALN 5-mg once-daily regimen.

Prevention of postmenopausal bone loss: six-year results from the Early Postmenopausal Intervention Cohort Study

We report the effect of continuous treatment with alendronate for 6 yr vs. placebo in the Early Postmenopausal Intervention Cohort study. A total of 1609 healthy, early postmenopausal women were recruited; we describe results for the 585 women who received continuous placebo or alendronate (2.5 or 5 mg) daily for 6 yr. Bone mineral density (BMD) was evaluated at the lumbar spine, hip, forearm, and total body at baseline and annually thereafter. Bone turnover markers were measured every 6 months from baseline to yr 2 and annually thereafter. Adverse experiences, including upper gastrointestinal events and fractures, were recorded throughout the study. Women receiving placebo experienced progressive decreases in BMD at all skeletal sites. Patients receiving alendronate experienced significant gains in spine and hip BMD that were maintained through yr 6. Significantly greater, dose-related decreases in bone turnover markers in the alendronate groups vs. placebo occurred within the first year and were sustained through yr 6. Women receiving alendronate had adverse experience incidences similar to those receiving placebo. Fractures occurred in 11.5, 10.3, and 8.9% of women taking placebo, 2.5 mg alendronate, or 5 mg alendronate daily, respectively. Therapy with alendronate is an effective and promising strategy for the prevention of postmenopausal osteoporosis.

Effects of discontinuation as well as intervention of cyclic therapy with etidronate on bone remodeling after cementless total hip arthroplasty

We previously reported the effects of cyclic therapy with etidronate (CTE) on periprosthetic bone mineral density (BMD) after cementless total hip arthroplasty (THA). This study aimed to evaluate the effects of withdrawal and intervention of CTE after cementless THA. The control group consisted of 24 patients without osteoactive drugs. Sixteen patients continued on CTE (i.e., 400 mg/day oral etidronate for 2 weeks followed by 12 weeks of 500 mg/day calcium lactate, repeated every 14 weeks) for the first 12 months followed by no treatment for 18 months (early-etidronate group). Fifteen patients received no treatment for the first 18 months followed by CTE for 12 months (late-etidronate group). Periprosthetic BMD in seven regions of interest based on the zones of Gruen et al. was measured with dual energy X-ray absorptiometry at 3 weeks, 6, 12, 18, 24, and 30 months postoperatively. At 12 months after operation (off therapy point in the early-etidronate group), postoperative decreases of BMD in the early-etidronate group were significantly smaller than those in the control group in zones 1, 2, 5, 6, and 7 and those in the late-etidronate group in zones 1, 5, 6, and 7 (P < 0.05 for each). In the early-etidronate group, significant decreases in BMD were found during months 12-30 (off therapy period) after withdrawal of CTE in zones 1 and 7 (P < 0.05 for each). In the late-etidronate group, BMD increased significantly in zones 4 and 6 (P < 0.05 for each) during months 18-30 (on therapy period) after intervention trial, while in the controls, BMD decreased significantly in zone 3 (P < 0.05) over this period. At the final follow-up (30 months), BMD loss in zone 7 was significantly less in the early-etidronate group than in the other groups (P < 0.05). BMD changes in the early-etidronate group and late-etidronate group were associated with changes in biochemical bone markers.

Ten years' experience with alendronate for osteoporosis in postmenopausal women

BACKGROUND

Antiresorptive agents are widely used to treat osteoporosis. We report the results of a multinational randomized, double-blind study, in which postmenopausal women with osteoporosis were treated with alendronate for up to 10 years.

METHODS

The initial three-year phase of the study compared three daily doses of alendronate with placebo. Women in the original placebo group received alendronate in years 4 and 5 and then were discharged. Women in the original active-treatment groups continued to receive alendronate during the initial extension (years 4 and 5). In two further extensions (years 6 and 7, and 8 through 10), women who had received 5 mg or 10 mg of alendronate daily continued on the same treatment. Women in the discontinuation group received 20 mg of alendronate daily for two years and 5 mg daily in years 3, 4, and 5, followed by five years of placebo. Randomized group assignments and blinding were maintained throughout the 10 years. We report results for the 247 women who participated in all four phases of the study.

RESULTS

Treatment with 10 mg of alendronate daily for 10 years produced mean increases in bone mineral density of 13.7 percent at the lumbar spine (95 percent confidence interval, 12.0 to 15.5 percent), 10.3 percent at the trochanter (95 percent confidence interval, 8.1 to 12.4 percent), 5.4 percent at the femoral neck (95 percent confidence interval, 3.5 to 7.4 percent), and 6.7 percent at the total proximal femur (95 percent confidence interval, 4.4 to 9.1 percent) as compared with base-line values; smaller gains occurred in the group given 5 mg daily. The discontinuation of alendronate resulted in a gradual loss of effect, as measured by bone density and biochemical markers of bone remodeling. Safety data, including fractures and stature, did not suggest that prolonged treatment resulted in any loss of benefit.

CONCLUSIONS

The therapeutic effects of alendronate were sustained, and the drug was well tolerated over a 10-year period. The discontinuation of alendronate resulted in the gradual loss of its effects.

Efficacy of intermittent low dose alendronate in Thai postmenopausal osteoporosis

Alendronate has been proven to be effective in the prevention and treatment of postmenopausal osteoporosis with the recommended daily dose of 10 mg. However, a constraining requirement for dosing limited its general acceptance in treatment. Since alendronate is potent and has a long half-life, weekly administration of alendronate in lower total doses might be safer and more convenient. The purpose of this study was to determine the efficacy of low dose once-weekly 20 mg alendronate in Thai postmenopausal women with osteoporosis. Thirty-nine postmenopausal women with osteoporosis received alendronate 20 mg once a week plus 750 mg elemental calcium daily. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at baseline and 6 and 12 months after treatment. Serum C-terminal telopeptide of type I collagen (CTx-I) was measured by electrochemiluminescence immunoassay at baseline and 3 months after treatment. By the end of 1 year, once weekly 20 mg alendronate significantly increased vertebral BMD (+6.2%, p < 0.001 vs baseline) from baseline whereas there was a reduction of 60.7% in serum CTx-I at 3 months. However, the BMD at femur did not increase significantly (+0.64%). Conclusion. Low-dose intermittent once-weekly 20 mg alendronate was effective, cost saving and had a good safety profile in increasing vertebral BMD and stabilizing BMD at the femoral neck in postmenopausal osteoporosis.

The Impact of Fragility Fracture on Health-Related Quality of Life

Both general and specific health status instruments can be utilised in evaluating health-related quality of life (HR-QOL) deficits resulting from osteoporotic fractures. Osteoporotic hip, vertebral and wrist fractures significantly decrease HR-QOL in most HR-QOL domains investigated. The presence of multiple vertebral fractures leads to larger decrements in HR-QOL. More research needs to be completed with these HR-QOL tools to better assess the true burden of osteoporotic fractures, particularly in the case of hip fractures, as the burden is surely being underestimated without recognition of HR-QOL. Only when the burden of fragility fractures is understood, inclusive of HR-QOL, will the value of proven antifracture prevention and treatment therapies be appreciated. Information collected by HR-QOL instruments may provide new insight as to how to improve quality of life for patients with fractures and how to properly allocate healthcare spending.

Effect of alendronate and exercise on bone and physical performance of postmenopausal women: a randomized controlled trial

In this randomized, double-blind, placebo-controlled 12-month trial we evaluated effects of weight- bearing jumping exercise and oral alendronate, alone or in combination, on the mass and structure of bone, risk factors for falling (muscle strength and power, postural sway, and dynamic balance), and cardiorespiratory fitness in postmenopausal women. A total of 164 healthy, sedentary, early postmenopausal women were randomly assigned to one of four experimental groups: (1) 5 mg of alendronate daily plus progressive jumping exercise, (2) 5 mg alendronate, (3) placebo plus progressive jumping exercise, or (4) placebo. The primary endpoint was 12-month change in bone mass and geometry (measured with dual-energy X-ray absorptiometry and peripheral computed tomography at several axial and limb sites) and physical performance; the secondary endpoint was change in biochemical markers of bone turnover. The jumping exercise was conducted an average 1.6 +/- 0.9 (mean +/- SD) times a week. Alendronate daily was effective in increasing bone mass at the lumbar spine (alendronate vs placebo 3.5%; 95% CI, 2.2-4.9%) and femoral neck (1.3%; 95% CI, 0.2-2.4%) but did not affect other bone sites. Exercise alone had no effect on bone mass at the lumbar spine or femoral neck; it had neither an additive nor an interactive effect with alendronate at these bone sites. However, at the distal tibia the mean increase of 3.6% (0.3-7.1%) in the section modulus (that is, bone strength) and 3.7% (0.1-7.3%) increase in the ratio of cortical bone to total bone area were statistically significant in the exercise group compared to the nonexercise group, indicating exercise-induced thickening of the bone cortex. Bone turnover was reduced in alendronate groups only. Alendronate had no effect on physical performance while the jumping exercise improved leg extensor power, dynamic balance, and cardiorespiratory fitness. As conclusion Alendronate is effective in increasing bone mass at the lumbar spine and femoral neck, while exercise is effective in increasing the mechanical properties of bone at some of the most loaded bone sites, as well as improving the participants' muscular performance and dynamic balance. Together alendronate and exercise may effectively decrease the risk of osteoporotic fractures.

Cyclic therapy with etidronate has a therapeutic effect against local osteoporosis after cementless total hip arthroplasty

Proximal bone resorption around the femoral stem is one of the major complications of cementless total hip arthroplasty (THA). The potential complications resulting from proximal bone resorption include femoral fracture and late stem loosening. The purpose of this study was to evaluate the effects of cyclic therapy with etidronate on periprosthetic bone mineral density (BMD) after cementless THA. Fifty-two patients who had undergone cementless THA were randomized for this study. Group A consisted of 30 hips in 29 patients without osteoactive drugs. Group B consisted of 23 hips in 23 patients with cyclic therapy with etidronate (i.e., 400 mg/day of oral etidronate for 2 weeks followed by 12 weeks of 500 mg/day of calcium lactate and repeated every 14 weeks), one of whom was excluded from the study because of side effects attributed to the drug. Periprosthetic BMD in seven regions of interest based on the zones of Gruen et al. (Clin. Orthop. 141 (1979), 17-27) was measured with dual energy X-ray absorptiometry (DXA) at 3 weeks, 6 months, and 12 months postoperatively. The postoperative decreases of BMD in group B were significantly lower than those in group A in zones 1 and 7 (P < 0.05 and P < 0.05, respectively) at 6 months and in zones 1, 2, 6, and 7 (P < 0.05, P < 0.05, P < 0.05, and P < 0.001, respectively) at 12 months. The BMD change appeared to be stabilized at 6 months in all zones in group B, while in group A there was a progressive decrease of average BMD (6.1%) in zone 7 between 6 months and 12 months. These findings suggested that cyclic therapy with etidronate may help to reduce the resorptive changes in the proximal part of the femur after cementless THA. Further follow-up study with larger populations will be required to define the potential efficacy of intermittent cyclic etidronate therapy on postoperative bone loss.

Bisphosphonate treatment of osteoporosis

Bisphosphonates represent the agents of choice for most patients with osteoporosis. They are the best studied of all agents for the prevention of bone loss and reduction in fractures. They increase BMD, primarily at the lumbar spine, but also at the proximal femur. In patients who have established osteoporosis, bisphosphonates reduce the risk of vertebral fractures, and are the only agents in prospective trials to reduce the risk of hip fractures and other nonvertebral fractures. Bisphosphonates reduce the risk of fracture quickly. The risk of radiographic vertebral deformities is reduced after 1 year of treatment with risedronate [68]. The risk of clinical vertebral fractures is reduced after 1 year of treatment with alendronate [69] and just 6 months' treatment with risedronate [157]. The antifracture effect of risedronate has been shown to continue through 5 years of treatment [158]. Alendronate and risedronate are approved by the FDA for prevention of bone loss in recently menopausal women, for treatment of postmenopausal osteoporosis, and for prevention (risedronate) and treatment (alendronate and risedronate) of glucocorticoid-induced osteoporosis. Alendronate is also approved for treatment of osteoporosis in men. Other bisphosphonates (etidronate for oral use, pamidronate and zoledronate for intravenous infusion) are also available and can be used off label for patients who cannot tolerate approved agents. Although bisphosphonates combined with estrogen or raloxifene produce greater gains in bone mass compared with single-agent treatment, the use of two antiresorptive agents in combination cannot be recommended because the benefit on fracture risk has not been demonstrated and because of increased cost and side effects.

Preventing osteoporotic fractures with bisphosphonates: a review of the efficacy and tolerability

Although change in bone mineral density was the outcome most commonly measured in early clinical trials of osteoporosis therapies, it is now understood that the most clinically important outcome is reduction in the risk of fractures. Of currently available osteoporosis therapies, the bisphosphonates have been most thoroughly investigated in studies with fracture risk as the primary outcome. The most widely studied bisphosphonates include etidronate, alendronate and risedronate. Alendronate and risedronate have the most compelling evidence for vertebral and non-vertebral fracture reduction. This review provides a comprehensive overview of the anti-fracture efficacy of bisphosphonates at the spine, hip, and non-vertebral sites.

Disintegration/dissolution profiles of copies of Fosamax (alendronate)

OBJECTIVE

Poor quality has been reported for some generics and other copies of original products. We performed a pilot study to compare the disintegration/dissolution profiles of FOSAMAX (alendronate) 70 mg tablets with those of copies of FOSAMAX that were manufactured outside the United States.

RESEARCH DESIGN AND METHODS

We used the standard United States Pharmacopeia (USP) disintegration method to evaluate FOSAMAX 70 mg tablets and 13 copies. At least 12 (n = 12) dosage units were tested for each product (except Fosmin, n = 10). The dissolution profiles of FOSAMAX and one representative copy were also compared.

RESULTS

Nine copies (Osteomax, Defixal, Fosmin, Endronax, Osteomix, Genalmen, Fixopan, Osteoplus, and Fosval) disintegrated two- to ten-fold faster than FOSAMAX. Three other copies (Neobon, Regenesis, and Ostenan) disintegrated at least five-fold slower than FOSAMAX. Neobon is a softgel capsule, so special consideration was given to this different dosage form. One copy (Arendal) did not fall into either category but exhibited potentially large inter- and intra-lot variability. Dissolution of alendronate from Regenesis lagged behind that from FOSAMAX.

CONCLUSION

Slower disintegration may reduce efficacy because bisphosphonates must be taken in the fasting state and contact with food or even certain beverages severely reduces bioavailability. Faster disintegration (or the use of gel-caps or other alterations to the drug formulation) could increase the risk of esophagitis, an adverse event associated with prolonged contact of the esophagus with bisphosphonates. These disintegration and dissolution results suggest that important differences may exist between FOSAMAX and its copies with regard to bioavailability, pharmacokinetics, and clinical efficacy and safety profiles. Additional testing is warranted to evaluate the pharmacokinetics and clinical safety of these copies.

Two-year results of once-weekly administration of alendronate 70 mg for the treatment of postmenopausal osteoporosis

The aim of this study was to provide confirmation that once-weekly dosing with 70 mg of alendronate (seven times the daily oral dose) and twice-weekly dosing with 35 mg is equivalent to the 10-mg once-daily regimen and to gain more extensive safety experience with this new dosing regimen. Twelve hundred fifty-eight postmenopausal women (aged 42-95 years) with osteoporosis (bone mineral density [BMD] of either lumbar spine or femoral neck at least 2.5 SDs below peak young adult mean or prior vertebral or hip fracture) were assigned to receive oral once-weekly alendronate, 70 mg (n = 519); twice-weekly alendronate, 35 mg (n = 369); or daily alendronate 10 mg (n = 370) for a total of 2 years of double-blind experience. Mean BMD increases from baseline (95% CI) at 24 months in the once-weekly, twice-weekly, and daily treatment groups, respectively, were 6.8% (6.4, 7.3), 7.0% (6.6,7.5), and 7.4% (6.9,7.8) at the lumbar spine and 4.1% (3.8,4.5), 4.3% (3.9,4.7), and 4.3% (3.9,4.7) at the total hip. These increases in BMD as well as the BMD increases at the femoral neck, trochanter, and total body and the reductions of biochemical markers of bone resorption (urinary cross-linked N-telopeptides of type I collagen [NTx]) and bone formation (serum bone-specific alkaline phosphatase [BSAP]) were similar for the three dosing regimens. All treatment regimens were well tolerated with a similar incidence of upper gastrointestinal (GI) adverse experiences. The incidence rates of clinical fractures, captured as adverse experiences, were similar among the groups. The 2-year results confirm the conclusion reached after 1 year that once-weekly alendronate is therapeutically equivalent to daily dosing, providing patients with a more convenient dosing option that may potentially enhance adherence to therapy.

Meta-analyses of therapies for postmenopausal osteoporosis. II. Meta-analysis of alendronate for the treatment of postmenopausal women

OBJECTIVE

To review the effect of alendronate on bone density and fractures in postmenopausal women.

DATA SOURCE

We searched MEDLINE, EMBASE, Current Contents, and the Cochrane Controlled trials registry from 1980 to 1999, and we examined citations of relevant articles and proceedings of international meetings.

STUDY SELECTION

We included 11 trials that randomized women to alendronate or placebo and measured bone density for at least 1 yr.

DATA EXTRACTION

For each trial, three independent reviewers assessed the methodological quality and abstracted data.

DATA SYNTHESIS

The pooled relative risk (RR) for vertebral fractures in patients given 5 mg or more of alendronate was 0.52 [95% confidence interval (CI), 0.43-0.65]. The RR of nonvertebral fractures in patients given 10 mg or more of alendronate was 0.51 (95% CI 0.38-0.69), an appreciably greater effect than for the 5 mg dose. We found a similar reduction in RR across nonvertebral fracture types; in particular, RR reductions for fractures traditionally thought to be "osteoporotic," such as hip and forearm, were very similar to RR reductions for "nonosteoporotic" fractures. Individual studies showed similar results, reflected in the P values of the test of heterogeneity (P = 0.99 for vertebral and 0.88 for nonvertebral fractures). Alendronate produced positive effects on the percentage change in bone density, which increased with both dose and time. After 3 yr of treatment with 10 mg of alendronate or more, the pooled estimate of the difference in percentage change between alendronate and placebo was 7.48% (95% CI 6.12-8.85) for the lumbar spine (2-3 yr), 5.60% (95% CI 4.80-6.39) for the hip (3-4 yr), 2.08% (95% CI 1.53-2.63) for the forearm (2-4 yr), and 2.73% (95% CI 2.27-3.20) for the total body (3 yr). Heterogeneity of the treatment effect of alendronate was not consistently explained by any of our a priori hypotheses; in particular, the effect was very similar in prevention and treatment studies. The pooled RR for discontinuing medication due to adverse effects for 5 mg or greater of alendronate was 1.15 (95% CI 0.93-1.42). The pooled RR for discontinuing medication due to gastro-intestinal (GI) side effects for 5 mg or greater was 1.03 (0.81-1.30, P = 0.83), and the pooled RR for GI adverse effects with continuation of medication was 1.03 (0.98 to 1.07) P = 0.23.

CONCLUSIONS

Alendronate increases bone density in both early postmenopausal women and those with established osteoporosis while reducing the rate of vertebral fracture over 2-3 yr of treatment. Reductions in nonvertebral fractures are evident among postmenopausal women without prevalent fractures and have bone mineral density (BMD) levels below the World Health Organization threshold for osteoporosis. The impact on fractures appears consistent across all fracture types, casting doubt on traditional distinctions between osteoporotic and nonosteoporotic fractures.

Curative effect of combined treatment with alendronate and 1 alpha-hydroxyvitamin D3 on bone loss by ovariectomy in aged rats

We investigated the combined effects of alendronate and 1alpha-hydroxyvitamin D3 (1alpha(OH)D3) on the bone mass and strength in aged ovariectomized rats and compared them with those of single treatments. Forty-week-old female rats underwent ovariectomy or sham operation, and after 15 weeks, ovariectomized rats were daily administered vehicle alone, alendronate (0.2 or 1.0 mg/kg,p.o.), 1alpha(OH)D3 (0.02 microg/kg, p.o.), or the combinations of 0.2 or 1.0 mg/kg of alendronate and 1alpha(OH)D3. After 12 weeks, the groups receiving combined treatments had significantly increased bone density and mechanical strength of the 4th lumbar vertebral body and the midfemur compared to the vehicle-treated group, and the effects were almost equal to or slightly less than the addition of those of the respective single treatments. The increase in mechanical strength was proportional to that in bone mineral density, suggesting that the stimulatory effects of these treatments on bone strength are ascribable primarily to those on bone mass. Analyses of histology, computed tomography, and biochemical markers confirmed the strong effect of the combined treatment on trabecular bone in particular, which was associated with increased trabecular number and decreased bone turnover. We propose that the combination of daily alendronate and 1alpha(OH)D3 is clinically promising as a curative treatment of established postmenopausal osteoporosis.

Alendronate increases bone mass and reduces bone markers in postmenopausal African-American women

Previous studies indicated that aminobisphosphonate alendronate sodium, a potent inhibitor of bone resorption, increases bone mineral density (BMD) at the hip and spine, reduces markers of bone turnover, and reduces the risk of fractures in Caucasian postmenopausal women. The purpose of the present study was to investigate whether alendronate increases BMD and reduces markers of bone turnover in African-American postmenopausal women. In a multicenter, randomized, double-blind, placebo-controlled study, 65 African-American women, aged 45 to 88 yr, were randomly assigned to either placebo (n = 33) or alendronate 10 mg daily (n = 32) for 2 yr. Mean BMD T scores of the lumbar spine at baseline were -3.18 in the placebo-treated group and -3.09 in the alendronate-treated group. All women took 500 mg elemental calcium daily in the form of calcium carbonate and 500 IU vitamin D. Alendronate significantly increased BMD and reduced markers of bone formation and resorption, compared with placebo. At 2 yr, mean changes +/- SE in BMD were 6.5% +/- 0.7% for the lumbar spine (P < 0.001), 4.5% +/- 1.0% for the femoral neck (P < 0.001), 6.4% +/- 0.6% for the femoral trochanter (P < 0.001), 4.1% +/- 0.7% for the total hip (P < 0.001), 0.7% +/- 0.5% for the one third forearm (NS), and 2.0% +/- 0.4% for the total body (P < 0.001) in women treated with alendronate, compared with 0.9% +/- 0.6% (NS), 0.5% +/- 1.1% (NS), -0.2 +/- 0.8 (NS), -1.1 +/- 0.7% (NS), -0.8% +/- 0.6% (NS), and -1.2% +/- 0.6% (P < 0.05) for the lumbar spine, femoral neck, trochanter, total hip, one third forearm, and total body, respectively, in women treated with placebo. At 2 yr, mean serum bone-specific alkaline phosphatase had declined by 46.3% with alendronate (P < 0.001) and 13.6% with placebo (P < 0.01), and mean urinary N-telopeptide of type I collagen/creatinine ratio had declined by 70.5% with alendronate (P < 0.001) and 6.7% with placebo (NS). The incidence of adverse experiences was not different between the two groups. We conclude that in postmenopausal African-American women with osteoporosis, alendronate, 10 mg daily for 2 yr, increases BMD at the lumbar spine, hip, and total body and reduces markers of bone remodeling and is well tolerated.

The gastrointestinal tolerability and safety of oral bisphosphonates

Oral bisphosphonates are effective for osteoporosis and other hyperresorptive bone disorders. Although well-tolerated in efficacy trials, some oral aminobisphosphonates have been associated with upper gastrointestinal intolerance and injury in postmarketing experience. Clinical trials often underestimate the rate of adverse events in clinical practice, and ethics prohibit direct evaluation of toxicity in high-risk patients. Accordingly, animal models and endoscopy studies of oral bisphosphonates provide valuable insight. It is unclear whether variation in ulcerogenic potential reflects differences in dosing, formulation or chemical structure. Furthermore, the clinical relevance of endoscopic lesions is uncertain. Ongoing postmarketing review will determine whether differences in endoscopic damage predict tolerability and safety in clinical practice. However, physicians and patients should consider risk factors for oesophageal injury when initiating therapy.

Upper gastrointestinal tract safety of risedronate: a pooled analysis of 9 clinical trials

Risedronate sodium is a pyridinyl bisphosphonate effective for treatment and prevention of postmenopausal and glucocorticoid-induced osteoporosis. Some bisphosphonates have been associated with upper gastrointestinal (GI) tract adverse effects. The objective of this study was to determine the frequency of upper GI tract adverse events associated with risedronate, especially among high-risk patients. The GI tract adverse events reported during 9 multicenter, randomized, double-blind, placebo-controlled studies of risedronate conducted from November 1993 to April 1998 were pooled and evaluated. The evaluation included 10,068 men and women who received placebo (n=5048) or 5 mg of risedronate sodium (n=5020) for up to 3 years (intent-to-treat population). Studies incorporated a comprehensive, prospective evaluation of GI tract adverse events. Adverse event information was collected every 3 months. The treatment groups were similar with respect to baseline GI tract disease and use of concomitant treatments during the studies. At study entry, 61.0% of patients had a history of GI tract disease and 38.7% had active GI tract disease; 20.5% used antisecretory drugs during the studies. Sixty-three percent used aspirin and/or nonsteroidal anti-inflammatory drugs (NSAIDs) during the studies. Upper GI tract adverse events were reported by 29.6% of patients in the placebo group compared with 29.8% in the risedronate group. The risk of experiencing such an event in the risedronate group was 1.01 (95% confidence interval, 0.94-1.09) relative to the placebo group (P=.77). The rate of upper GI tract adverse events per 100 patient-years was 19.2 in the placebo group compared with 20.0 in the risedronate group (P=.30). Risedronate-treated patients with active heartburn, esophagitis, other esophageal disorders, or peptic ulcer disease at study entry did not experience worsening of their underlying conditions or an increased frequency of upper GI tract adverse events overall. Concomitant use of NSAIDs, requirement for gastric antisecretory drugs, or the presence of active GI tract disease did not result in a higher frequency of upper GI tract adverse events in the risedronate-treated patients compared with controls. Endoscopy, performed in 349 patients, demonstrated no statistically significant differences across treatment groups. The results of this extensive evaluation indicate that daily treatment with 5 mg of risedronate sodium is not associated with an increased frequency of adverse GI tract effects, even among patients at high risk for these events.

Intravenous zoledronic acid in postmenopausal women with low bone mineral density

BACKGROUND

Bisphosphonates are effective agents for the management of osteoporosis. Their low bioavailability and low potency necessitate frequent administration on an empty stomach, which may reduce compliance. Gastrointestinal intolerance limits maximal dosing. Although intermittent intravenous treatments have been used, the optimal doses and dosing interval have not been systematically explored.

METHODS

We studied the effects of five regimens of zoledronic acid, the most potent bisphosphonate, on bone turnover and density in 351 postmenopausal women with low bone mineral density in a one-year, randomized, double-blind, placebo-controlled trial. Women received placebo or intravenous zoledronic acid in doses of 0.25 mg, 0.5 mg, or 1 mg at three-month intervals. In addition, one group received a total annual dose of 4 mg as a single dose, and another received two doses of 2 mg each, six months apart. Lumbar-spine bone mineral density was the primary end point.

RESULTS

There were similar increases in bone mineral density in all the zoledronic acid groups to values for the spine that were 4.3 to 5.1 percent higher than those in the placebo group (P<0.001) and values for the femoral neck that were 3.1 to 3.5 percent higher than those in the placebo group (P<0.001). Biochemical markers of bone resorption were significantly suppressed throughout the study in all zoledronic acid groups. Myalgia and pyrexia occurred more commonly in the zoledronic acid groups, but treatment-related dropout rates were similar to that in the placebo group.

CONCLUSIONS

Zoledronic acid infusions given at intervals of up to one year produce effects on bone turnover and bone density as great as those achieved with daily oral dosing with bisphosphonates with proven efficacy against fractures, suggesting that an annual infusion of zoledronic acid might be an effective treatment for postmenopausal osteoporosis.

Sintered dicalcium pyrophosphate increases bone mass in ovariectomized rats

Bisphosphonates are synthetic pyrophosphate analogs that can be used for the treatment of osteoporosis. Sintered dicalcium pyrophosphate, as a pyrophosphate analog, may be useful in the clinical setting for osteoporosis. In this study, an ovariectomized rat model is used to evaluate the effects of orally administered sintered dicalcium pyrophosphate on bone mass. Thirty-six female rats were used in this study. They randomly were divided into six groups: a negative normal control group, a positive osteoporosis control group, and ovariectomized groups treated either with alendronate sodium (one group) or sintered dicalcium pyrophosphate (three groups, each at a different level). The animals were sacrificed at 4 weeks after treatment. For all the rats, whole blood samples were obtained for the biochemical study. Bone ashes of long bones were measured and studied and histologic studies of cancellous bone were carried out. The ingestion of either alendronate or sintered dicalcium pyrophosphate did not have any deleterious effect on the major visceral organs. Ingestion of alendronate or sintered pyrophosphate decreased the bony porosity and increased bone mineral contents in the long bones of ovariectomized rats. Thus sintered dicalcium pyrophosphate can increase bone mass in the ovariectomized rat.

Postmenopausal survivors of breast cancer at risk for osteoporosis: nutritional intake and body size

Postmenopausal survivors of breast cancer for whom hormone replacement therapy is contraindicated are at risk for development of osteoporosis. The primary purpose of this article is to describe, in a sample of 30 postmenopausal survivors of breast cancer, their calcium and vitamin D intake compared with recommended dietary guidelines for those nutrients for postmenopausal women not taking hormone replacement therapy and the body mass index of these women as nutritional status risk factors for development of osteoporosis. Bone health and presence of osteoporosis were determined by bone mineral density testing of the spine, hip, and forearm. To obtain calcium and vitamin D intake, including supplements, 3-day diet records were completed; height and weight measures were used to calculate body mass index. The sample participants ranged in age from 42 to 65 years; the majority (56%) had been menopausal or off hormone replacement therapy for 5 years or less, and 70% had completed breast cancer treatment for 5 years or less (except tamoxifen). The majority (63%) were of medium body frame size; 30% were of small frame size. The mean body mass index (27.3) and mean weight (160 lbs) indicate that these women, as a group, were over-weight. Although a large percent (63%) were taking calcium supplements, the mean daily intake (diet and supplements) of calcium (1,353 mg) and vitamin D (403 IU) was less than the recommended dietary guidelines for these nutrients in this population. At study entry, 80% of the women were osteopenic (60%) or osteoporotic (20%) and none was receiving treatment/prevention for osteoporosis; only 1 had a previous known osteoporosis diagnosis. This is a special group of women for whom screening and preventive strategies for osteoporosis are imperative.

Corticosteroid-Induced osteoporosis: detection and management

Corticosteroid-induced osteoporosis is a major cause of morbidity and is the leading secondary cause of osteoporosis today. Unfortunately, despite this knowledge, patients receiving corticosteroid therapy are often not offered any preventative treatment. Recent research has focused attention on the critical role the osteoblast has played in the pathophysiology of corticosteroid-induced osteoporosis. In addition to an initial increase in bone resorption, there is evidence that corticosteroids induce osteoblast and osteocyte apoptosis and as a result are important contributors to bone loss. Interesting work has suggested that the bisphosphonates and calcitonin may help to prevent osteoblast apoptosis from occurring. Large scale randomised controlled trials have also been completed with a variety of therapeutic agents. Of the many different therapies, it is now clear that the bisphosphonates have the greatest evidence to support their use. Increases in bone mineral density when compared with a control group, not only at the spine but also at the hip, have been demonstrated. These studies have shown clinically significant reductions in vertebral fracture rates seen for the most part in postmenopausal women. Other therapies may well be effective, as evidenced by maintenance of bone mass in the spine; however, maintenance of bone mass in the hip and reductions in fracture rate have yet to be demonstrated for many of these therapies. Given our current knowledge and the evidence that is outlined in this review, it is hoped that patients who require therapy with corticosteroids for more than 3 months will be offered appropriate preventative treatment.

Alendronate reduces periprosthetic bone loss after uncemented primary total hip arthroplasty: a prospective randomized study

Periprosthetic bone loss, especially in the proximal part of the femur, is common after cemented and uncemented total hip arthroplasty (THA). Bone loss can be progressive and, in the extreme, may threaten survival of the prosthesis. To study whether alendronate therapy can reduce bone loss adjacent to prostheses, 13 uncemented primary THA patients were randomized to the study. They received 10 mg alendronate + 500 mg calcium (n = 8) or 500 mg calcium only (n = 5) daily for 6 months follow-up after THA. Periprosthetic bone mineral density (BMD) was measured with dual energy X-ray absorptiometry (DXA). Decreases in periprosthetic BMD in the alendronate-treated group were lower compared with the changes in the calcium-only group in the same regions of interest at the same follow-up time. In the proximal femur, the mean BMD decrease was 17.1% in the calcium-only group, whereas in the alendronate-treated group the decrease was only 0.9% (p = 0.019). The mean periprosthetic BMD change was also significantly different in the total periprosthetic area between the study groups at the end of the follow-up (calcium-only group -9.9% vs. alendronate-treated group -2.6%; p = 0.019). Alendronate therapy led to a significant reduction in periprosthetic bone loss after primary uncemented THA compared with the changes found in patients without therapy. This kind of bone response may improve the support of the prosthesis and may result in better survival of the prosthesis. However, in this study the follow-up time was too short and the study population was too small to make any long-term conclusions as to the prognosis for THA patients treated with alendronate.

Tolerability of risedronate in postmenopausal women intolerant of alendronate

Bisphosphonates are effective treatments for osteoporosis, but some have been associated with upper gastrointestinal intolerance. This randomized, double-blind study assessed the upper gastrointestinal tolerability of risedronate in postmenopausal women who had discontinued alendronate treatment because of upper gastrointestinal adverse events. Sixty-six women who had previously discontinued treatment with alendronate 10 mg/day because of upper gastrointestinal symptoms received placebo (N=31) or risedronate 5 mg (N=35) daily for 3 months. The primary outcome was the rate of discontinuation due to upper gastrointestinal adverse events: 5/31 (16.1%) in the placebo group, and 4/35 (11.4%) in the risedronate group. Discontinuation rates were also similar in the two treatment groups among subgroups of patients with a history of gastrointestinal disorder, prior use of acid suppression drugs, and concomitant use of NSAIDs. The overall incidence of upper gastrointestinal events was comparable between the placebo (19.4%) and risedronate (20.0%) groups. Overall, risedronate 5 mg/day for 3 months was as well tolerated as placebo in patients who could not tolerate alendronate 10 mg. These results are consistent with, and complement those from previous studies showing that risedronate 5 mg has a gastrointestinal tolerability similar to that of placebo.

Update on alendronate for osteoporosis: once-weekly dosing

Alendronate (Fosamax, Merck & Co.) is now available in a 70 mg formulation to be taken once a week for osteoporosis. Earlier studies demonstrated that alendronate is highly effective for increasing bone density, reducing bone turnover rate and reducing the risk of fractures. A subsequent clinical trial reported that the once-weekly dosing regimen is therapeutically equivalent to the daily regimen. Administering alendronate (70 mg) once a week effectively provides continuous inhibition of bone resorption because bone resorption by osteoclasts is a slow process that typically requires 2-3 weeks for completion and alendronate remains at active bone remodelling sites for a sustained period and (when present in sufficient concentration) effectively inhibits bone resorption. Bisphosphonates are currently the pre-eminent therapy for osteoporosis. Once-weekly alendronate represents a major advance in convenience because oral bisphosphonates must be taken in the fasting state with water at least 30 minutes before consuming food or beverages. Sales data several months after introduction of once-weekly alendronate into the marketplace demonstrate rapid and extensive acceptance of this new regimen.

Bone mineral density in postmenopausal breast cancer survivors

PURPOSE

The overall purpose of this longitudinal 18-month study was to test the feasibility and effectiveness of a multicomponent intervention for prevention and treatment of osteoporosis. The purpose of this article is to describe the baseline bone mineral density (BMD) findings for 30 postmenopausal women and to compare these BMD findings to time since menopause, body mass index, and tamoxifen use.

DATA SOURCES

Baseline data of BMD findings for 30 postmenopausal women, who have had a variety of treatments including surgery, adjuvant chemotherapy and or tamoxifen, and are enrolled in the 18-month longitudinal study. A demographic questionnaire and a three day dietary record were used to collect baseline data.

CONCLUSIONS

Eighty percent of the women with breast cancer history had abnormal BMDs at baseline (t-scores below -1.00 SD). Thinner women showed a greater risk for accelerated trabecular bone loss at the spine and hip.

IMPLICATIONS FOR PRACTICE

These findings suggest the need for early BMD assessments and for aggressive health promotion intervention strategies that include a multifaceted protocol of drug therapy for bone remodeling, 1500 mg of daily calcium, 400 IU vitamin D and a strength weight training program that is implemented immediately following chemotherapy treatment and menopause in this high risk population of women.

Long-term effects of withdrawal of bisphosphonate incadronate disodium (YM175) on bone mineral density, mass, structure, and turnover in the lumbar vertebrae of ovariectomized rats

This study was designed to evaluate the long-term effects of incadronate disodium (YM175) after its withdrawal on cancellous bone mass in ovariectomized (OVX) rats. Thirteen-week-old female SD rats were randomized into four groups: sham-operated, OVX, low-YM, and high-YM (0.01 mg/kg or 0.1 mg/kg subcutaneously [sc], three times a week after OVX) groups. After 4 weeks of treatment with vehicle or YM175, rats from each group were killed at time points of 0 (baseline), 3, 6, 9, and 12 months after withdrawal of the agent. Bone mineral density (BMD) of the lumbar vertebrae was measured by dual-energy X-ray absorptiometry (DXA). Bone volume (BV/TV), trabecular number and trabecular separation (Tb.N and Tb.Sp), eroded surface (ES/BS), osteoclast number and osteoclast surface (N.Oc/BS and Oc.S/BS), osteoid surface (OS/BS), and bone formation rate (BFR/BS) were measured as histomorphometric parameters of the fifth lumbar vertebra. BMD, BV/TV, Tb.N, and Tb.Sp in YM175-treated groups were maintained at the same level as in the sham group until 12 months after withdrawal in the high-YM group and until 3 months after withdrawal in the low-YM group. YM175 decreased both bone formative and resorptive parameters in histomorphometry. Serum bone-specific alkaline phosphatase (ALP) and urinary deoxypyridinoline at both doses of YM175 also showed a suppressive effect of this agent on bone turnover. These results indicate that YM175, after withdrawal, still maintains bone volume dose dependently by depressing bone resorption and formation in OVX rats. Intermittent YM175 treatment with a long interval may be sufficient to maintain the bone volume and structure in OVX rats.

Treatment of osteoporosis with bisphosphonates

Bisphosphonates are safe and effective agents for treatment and prevention of osteoporosis. Alendronate and risedronate are the best studied of all agents for osteoporosis in terms of efficacy and safety. They increase bone mass. In patients who have established osteoporosis, they reduce the risk of vertebral fractures. They are the only agents shown in prospective trials to reduce the risk of hip fractures and other nonvertebral fractures. They are approved by the US FDA for prevention of bone loss in recently menopausal women, for treatment of postmenopausal osteoporosis, and for management of glucocorticoid-induced bone loss. Other bisphosphonates (e.g., etidronate for oral use, pamidronate for intravenous infusion) are also available and can be used off-label for patients who cannot tolerate approved agents. Bisphosphonates combined with estrogen produce greater gains in bone mass compared with either agent used alone; whether there is a greater benefit of combination therapy on fracture risk is not clear. Combining a bisphosphonate with raloxifene or calcitonin is probably safe, although data on effectiveness are lacking.

Alendronate prevents bone loss in Chinese women with osteoporosis

The objectives of the Hong Kong study are to investigate the efficacy of 10 mg alendronate in preventing bone loss at the hip and spine in osteoporotic Chinese women. One hundred osteoporotic Chinese women, aged 60-79 years, were randomized to receive 10 mg of alendronate or placebo, with 500 mg elemental calcium. Bone mineral density (BMD) at the spine and hip were measured at baseline, 6 months, and 12 months. Seventy-eight subjects completed the study. The alendronate-treated group gained more bone at both the spine (p < 0.01) and femoral neck (p < 0.001), with a mean difference (+/-SE) of 2.4% (+/-0.86%) at the spine and 3.98% (+/-0.95%) at the femoral neck. Of the 100 patients, 6 subjects in the alendronate group and 5 subjects in the placebo group had mild gastrointestinal symptoms. We conclude that alendronate (10 mg) was effective in preventing bone loss in postmenopausal osteoporotic Chinese women.

Alendronate increases lumbar spine bone mineral density in patients with Crohn's disease

BACKGROUND & AIMS

Low bone mineral density (BMD) is a common complication of Crohn's disease and may lead to increased morbidity and mortality because of fractures. We investigated the effect of treatment with the bisphosphonate alendronate on bone mass and markers of bone remodeling in patients with Crohn's disease.

METHODS

A 12-month double-blind, randomized, placebo-controlled trial examined the effect of a 10-mg daily dose of alendronate. Thirty-two patients with a bone mass T score of -1 of the hip or lumbar spine were studied. The main outcome measure was the difference in the mean percent change in BMD of the lumbar spine measured by dual-energy x-ray absorptiometry. Secondary outcome measures included changes in BMD of the hip and total body and biochemical markers of bone turnover (S-osteocalcin, urine pyridinoline, and urine deoxypyridinoline excretion).

RESULTS

Mean (+/-SEM) BMD of the lumbar spine showed an increase of 4.6% +/- 1.2% in the alendronate group compared with a decrease of 0.9% +/- 1.0% in patients receiving placebo (P < 0.01). BMD of the hip increased by 3.3% +/- 1.5% in the alendronate group compared with a smaller increase of 0.7% +/- 1.1% in the placebo group (P = 0.08). Biochemical markers of bone turnover decreased significantly in the alendronate group (P < 0.001). Alendronate was well tolerated, and there was no difference in adverse events among treatment groups.

CONCLUSIONS

Treatment with alendronate, 10 mg daily, significantly increased BMD in patients with Crohn's disease and was safe and well tolerated.

Transdermal delivery of drugs for the treatment of bone diseases

The current status of transdermal drug delivery for the treatment of bone diseases is described in this review. The structure, physiology and function of skin and their importance in determining delivery into and across skin are discussed. Special emphasis has been devoted to a description of the major pathways of transport across the skin and the quite continuing controversy over the importance of the transfollicular route. An overview of anatomic site-dependent drug absorption is also provided and is particularly relevant to determination of transdermal patch location. Brief descriptions of the criteria for selection of transdermal drug candidate, transdermal patch designs and currently marketed transdermal products are also included. Transdermal estradiol delivery systems are examined in more detail for their clinical and biological effects. Finally, the feasibility of delivering drugs such as bisphosphonates across skin is discussed.

Prevention and treatment of osteoporosis in women with breast cancer

Women who have had breast cancer may be at higher risk for osteoporosis than other women. First, they are more likely to undergo early menopause, due to chemotherapy-induced ovarian failure or oopherectomy. In addition, chemotherapy may have a direct adverse effect on bone mineral density (BMD), and osteoclastic activity may increase from the breast cancer itself. While estrogen therapy is considered standard for the prevention and treatment of osteoporosis, use of estrogen in women with a history of breast cancer is usually contraindicated. The approach to osteoporosis in women with breast cancer is also affected by the use of tamoxifen in many, as this drug appears to have opposite effects on BMD in premenopausal and postmenopausal women. We have reviewed therapeutic alternatives for the prevention and treatment of osteoporosis, focusing on patients with a history of breast cancer. Alendronate and raloxifene are currently approved in the United States for the prevention of osteoporosis; alendronate, raloxifene, and calcitonin are approved for treatment. Alendronate has the greatest positive effect on BMD and reduces the incidence of vertebral and nonvertebral fractures. Raloxifene and calcitonin appear to reduce the incidence of vertebral fractures; their effects on the incidence of nonvertebral fractures are not yet proven. Although no published studies specifically address the use of these approved agents for osteoporosis in women with breast cancer, understanding their relative effects on BMD in postmenopausal women in general will facilitate therapy selection in this population. Postmenopausal women with a history of breast cancer should undergo bone mineral analysis. Normal results and absence of other risk factors ensure that calcium and vitamin D intake are adequate. If osteopenia or other risk factors are present, preventive therapy with alendronate or raloxifene should be considered. For osteoporosis, treatment with alendronate should be strongly considered. Raloxifene and calcitonin are alternatives when alendronate is contraindicated. Further studies are needed to evaluate the optimal timing of initial bone mineral analysis in premenopausal women after breast cancer diagnosis and to determine the value of preventive treatment in women scheduled to undergo chemotherapy.

Does suppression of bone turnover impair mechanical properties by allowing microdamage accumulation?

One plausible purpose of bone turnover is to repair bone microdamage. We hypothesized that suppression of bone turnover impairs bone quality by allowing accumulation of microdamage. We investigated the effect of high-dose etidronate (EHDP) on bone's mechanical properties and microdamage accumulation. Skeletally mature beagles, 1-2 years old at the beginning of the study, were treated with daily injections of vehicle or EHDP at 0.5 mg/kg per day or 5.0 mg/kg per day for 1 year. X-rays were taken at baseline and monthly from 7 to 12 months. Bones were taken upon sacrifice and biomechanical tests, histomorphometry, and microdamage analyses were performed. Fractures of ribs and/or thoracic spinous processes were found in 10 of 11 dogs treated with the higher dose EHDP. Only one fracture of a thoracic spinous process was found in dogs treated with the lower dose EHDP, and no fractures were found in the vehicle controls. Biomechanical tests showed reduced mechanical strength in ribs and lumbar vertebrae, but not in the femoral diaphysis or thoracic spinous process in the higher dose EHDP group. Histomorphometric measurements showed a significant reduction of cancellous bone turnover in both EHDP-treated groups compared with controls. In dogs treated with the higher dose EHDP, activation frequency was reduced to zero in both cortical and cancellous bone. Osteoid volume increased significantly, especially in trabecular bone, resulting in reduced mineralized bone volume in the higher dose EHDP group. Microcrack numerical density (Cr.Dn) increased significantly only in the lumbar vertebral body in the higher dose EHDP group, but not in the rib or thoracic spinous process where fractures occurred. These findings show that suppression of bone turnover using high doses of EHDP is associated with fractures of the ribs and spinous processes in dogs. This is most likely the result of excessive amounts of unmineralized bone produced by the inhibition of mineralization at these high doses, rather than by the accumulation of microdamage.

Effects of alendronate on bone quality and remodeling in glucocorticoid-induced osteoporosis: a histomorphometric analysis of transiliac biopsies

Effects of alendronate (ALN) on bone quality and turnover were assessed in 88 patients (52 women and 36 men aged 22-75 years) who received long-term oral glucocorticoid exposure. Patients were randomized to receive oral placebo or alendronate 2.5, 5, or 10 mg/day for 1 year and stratified according to the duration of their prior glucocorticoid treatment. Transiliac bone biopsies were obtained for qualitative and quantitative analysis after tetracycline double-labeling at the end of 1 year of treatment. As previously reported in glucocorticoid-induced osteoporosis, low cancellous bone volume and wall thickness were noted in the placebo group as compared with normal values. Alendronate treatment was not associated with any qualitative abnormalities. Quantitative comparisons among the four treatment groups were performed after adjustment for age, gender, and steroid exposure. Alendronate did not impair mineralization at any dose as assessed by mineralization rate. Osteoid thickness (O.Th) and volume (OV/BV) were significantly lower in alendronate-treated patients, irrespective of the dose (P = 0.0003 and 0.01, respectively, for O.Th and OV/BV); however, mineral apposition rate was not altered. As anticipated, significant decreases of mineralizing surfaces (76% pooled alendronate group; P = 0.006), activation frequency (-72%; P = 0.004), and bone formation rate (-71%; P = 0.005) were also noted with alendronate treatment. No significant difference was noted between the changes observed with each dose. Absence of tetracycline label in trabecular bone was noted in approximately 4% of biopsies in placebo and alendronate-treated groups. Trabecular bone volume, parameters of microarchitecture, and resorption did not differ significantly between groups. In conclusion, alendronate treatment in patients on glucocorticoids decreased the rate of bone turnover, but did not completely suppress bone remodeling and maintained normal mineralization at all alendronate doses studied. Alendronate treatment did not influence the osteoblastic activity, which is already low in glucocorticoid-induced osteoporosis.

Management of corticosteroid-induced osteoporosis

OBJECTIVES

To educate scientists and health care providers about the effects of corticosteroids on bone, and advise clinicians of the appropriate treatments for patients receiving corticosteroids.

METHODS

This review summarizes the pathophysiology of corticosteroid-induced osteoporosis, describes the assessment methods used to evaluate this condition, examines the results of clinical trials of drugs, and explores a practical approach to the management of corticosteroid-induced osteoporosis based on data collected from published articles.

RESULTS

Despite our lack of understanding about the biological mechanisms leading to corticosteroid-induced bone loss, effective therapy has been developed. Bisphosphonate therapy is beneficial in both the prevention and treatment of corticosteroid-induced osteoporosis. The data for the bisphosphonates are more compelling than for any other agent. For patients who have been treated but continue to lose bone, hormone replacement therapy, calcitonin, fluoride, or anabolic hormones should be considered. Calcium should be used only as an adjunctive therapy in the treatment or prevention of corticosteroid-induced bone loss and should be administered in combination with other agents.

CONCLUSIONS

Bisphosphonates have shown significant treatment benefit and are the agents of choice for both the treatment and prevention of corticosteroid-induced osteoporosis.

Glucocorticoid-induced osteoporosis

This article attempts to evaluate the results of several recently published clinical trials of drugs used in the treatment and prevention of glucocorticoid-induced osteoporosis. Despite our lack of understanding regarding the biological mechanisms that lead to glucocorticoid-induced bone loss, effective therapy has been developed. Bisphosphonates have demonstrated significant treatment benefits and should be considered the therapy of choice for both the treatment and prevention of glucocorticoid-induced osteoporosis.

Bisphosphonates in osteoporosis: recent clinical experience

Bisphosphonates are potent inhibitors of bone resorption that have come to play a prominent role in the prevention and treatment of various forms of osteoporosis and other metabolic bone disorders. Therapy in women with osteoporosis and at high fracture risk substantially reduces the incidence of vertebral and non-vertebral fractures. In younger postmenopausal women, bisphosphonates are attractive alternatives to oestrogen to prevent bone loss and the subsequent development of osteoporosis. Bisphosphonates have recently become the treatment of choice to prevent and treat the skeletal consequences of chronic corticosteroid therapy. When administered appropriately, these drugs are very well tolerated and have an excellent safety profile. The challenges now to clinicians are to identify the patients for whom bisphosphonate therapy is indicated and to devise dosing and monitoring strategies to enhance the long-term adherence to therapy required to realise the full benefits of these treatments.

Alendronate and estrogen-progestin in the long-term prevention of bone loss: four-year results from the early postmenopausal intervention cohort study. A randomized, controlled trial

BACKGROUND

Up to 3 years of treatment with alendronate, 5 mg/d, prevents postmenopausal bone loss.

OBJECTIVE

To determine whether the effect of alendronate is sustained at 4 years of treatment and persists after treatment is discontinued.

DESIGN

Randomized, controlled trial.

SETTING

United States and Europe.

PARTICIPANTS

1609 postmenopausal women 45 to 59 years of age.

INTERVENTION

Participants were randomly assigned to receive oral alendronate, 5 mg/d or 2.5 mg/d; placebo; or open-label estrogen-progestin. Women in the alendronate groups received alendronate for the first 2 years of the study. Treatment was then continued without change or replaced with placebo for the last 2 years of the study.

MEASUREMENTS

Annual measurement of bone mineral density.

RESULTS

By year 4, the bone mineral density of participants in the placebo group had decreased by 1% to 6% (P < 0.001). Four years of treatment with 5 mg of alendronate per day increased bone mineral density at the spine (mean change [+/-SE], 3.8%+/-0.3%), hip (mean, 2.9%+/-0.2%), and total body (mean, 0.9%+/-0.2%) (P < 0.001 overall). By year 4, bone mineral density at most skeletal sites was greater in participants who switched from alendronate to placebo than in those who continuously received placebo. In years 3 and 4, bone loss in participants who switched from alendronate to placebo was similar to that seen during years 1 and 2 in those who continuously received placebo. Compared with 5 mg of alendronate per day, estrogen-medroxyprogesterone acetate produced similar increases in bone mineral density and estradiol-norethisterone acetate produced increases that were substantially greater.

CONCLUSIONS

Four years of treatment with alendronate or estrogen-progestin prevented postmenopausal bone loss. A residual effect was seen 2 years after alendronate therapy was stopped; however, continuous alendronate treatment was more effective in preventing postmenopausal bone loss than 2 years of alendronate followed by 2 years of placebo.

Bone anabolic effects of basic fibroblast growth factor in ovariectomized rats

The purpose of this study was to characterize the bone anabolic effects of basic fibroblast growth factor (bFGF) in ovariectomized (OVX) rats. Female Sprague Dawley rats were subjected to ovariectomy or sham surgery at 3 months of age and maintained untreated for 2 months post surgery. Groups of OVX rats were then treated iv with bFGF at doses of 100 or 200 microg/kg day for 7 or 14 days. Another group of OVX rats and a group of sham-operated control rats were treated iv with vehicle alone for 14 days. Certain groups of bFGF-treated OVX rats were killed at 7 or 14 days after withdrawal of treatment. The right tibiae were processed undecalcified for quantitative bone histomorphometry. Vehicle-treated OVX rats were characterized by decreased cancellous bone volume associated with increased bone turnover. Treatment of OVX rats with bFGF strongly stimulated bone formation, as indicated by marked increases of at least a factor of 10 in osteoblast surface, osteoid surface, and osteoid volume. Furthermore, new osteoid spicules were observed within the marrow cavity of these animals. Osteoclast surface was markedly decreased in bFGF-treated OVX rats, but this finding may be secondary to the extensive osteoid surface. The strongest bone anabolic effects occurred in OVX rats treated with the higher dose of bFGF for 14 days, but these animals exhibited a bone mineralization defect, as evidenced by abundant osteoid and a lack of double fluorochrome labeling, despite markedly increased osteoblast surface. However, the newly-formed osteoid rapidly calcified after withdrawal of bFGF treatment. The data indicate that bFGF not only stimulates bone formation on pre-existing bone surfaces but also induces de novo formation of bone spicules within the marrow cavity, which results in partial restoration of lost cancellous bone mass in osteopenic OVX rats after only 14 days of treatment with the growth factor. These findings suggest that bFGF merits consideration for development as a potential treatment for patients with severe osteopenia who are unresponsive to conventional osteoporosis therapies.

Intermittent and continuous administration of the bisphosphonate ibandronate in ovariohysterectomized beagle dogs: effects on bone morphometry and mineral properties

Bisphosphonates have emerged as a valuable treatment for postmenopausal osteoporosis. Bisphosphonate treatment is usually accompanied by a 3-6% gain in bone mineral density (BMD) during the first year of treatment and by a decrease in bone turnover. Despite low bone turnover, BMD continues to increase slowly beyond the first year of treatment. There is evidence that bisphosphonates not only increase bone volume but also enhance secondary mineralization. The present study was conducted to address this issue and to compare the effects of continuous and intermittent bisphosphonate therapy on static and dynamic parameters of bone structure, formation, and resorption and on mineral properties of bone. Sixty dogs were ovariohysterectomized (OHX) and 10 animals were sham-operated (Sham). Four months after surgery, OHX dogs were divided in six groups (n = 10 each). They received for 1 year ibandronate daily (5 out of 7 days) at a dose of 0, 0.8, 1.2, 4.1, and 14 microg/kg/day or intermittently (65 microg/kg/day, 2 weeks on, 11 weeks off). Sham dogs received vehicle daily. At month 4, there was a significant decrease in bone volume in OHX animals (p < 0.05). Doses of ibandronate >/= 4.1 microg/kg/day stopped or completely reversed bone loss. Bone turnover (activation frequency) was significantly depressed in OHX dogs given ibandronate at the dose of 14 microg/kg/day. This was accompanied by significantly higher crystal size, a higher mineral-to-matrix ratio, and a more uniformly mineralized bone matrix than in control dogs. This finding lends support to the hypothesis that an increase in secondary mineralization plays a role in gain in BMD associated with bisphosphonate treatment. Moreover, intermittent and continuous therapies had a similar effect on bone volume. However, intermittent therapy was more sparing on bone turnover and bone mineral properties. Intermittent therapy could therefore represent an attractive alternative approach to continuous therapy.

Pharmacokinetics of alendronate

Alendronate (alendronic acid; 4-amino-1-hydroxybutylidene bisphosphonate) has demonstrated effectiveness orally in the treatment and prevention of postmenopausal osteoporosis, corticosteroid-induced osteoporosis and Paget's disease of the bone. Its primary mechanism of action involves the inhibition of osteoclastic bone resorption. The pharmacokinetics and pharmacodynamics of alendronate must be interpreted in the context of its unique properties, which include targeting to the skeleton and incorporation into the skeletal matrix. Preclinically, alendronate is not metabolised in animals and is cleared from the plasma by uptake into bone and elimination via renal excretion. Although soon after administration the drug distributes widely in the body, this transient state is rapidly followed by a nonsaturable redistribution to skeletal tissues. Oral bioavailability is about 0.9 to 1.8%, and food markedly inhibits oral absorption. Removal of the drug from bone reflects the underlying rate of turnover of the skeleton. Renal clearance appears to involve both glomerular filtration and a specialised secretory pathway. Clinically, the pharmacokinetics of alendronate have been characterised almost exclusively based on urinary excretion data because of the extremely low concentrations achieved after oral administration. After intravenous administration of radiolabelled alendronate to women, no metabolites of the drug were detectable and urinary excretion was the sole means of elimination. About 40 to 60% of the dose is retained for a long time in the body, presumably in the skeleton, with no evidence of saturation or influence of one intravenous dose on the pharmacokinetics of subsequent doses. The oral bioavailability of alendronate in the fasted state is about 0.7%, with no significant difference between men and women. Absorption and disposition appear independent of dose. Food substantially reduces the bioavailability of oral alendronate; otherwise, no substantive drug interactions have been identified. The pharmacokinetic properties of alendronate are evident pharmacodynamically. Alendronate treatment results in an early and dose-dependent inhibition of skeletal resorption, which can be followed clinically with biochemical markers, and which ultimately reaches a plateau and is slowly reversible upon discontinuation of the drug. These findings reflect the uptake of the drug into bone, where it exerts its pharmacological activity, and a time course that results from the long residence time in the skeleton. The net result is that alendronate corrects the underlying imbalance in skeletal turnover characteristic of several disease states. In women with postmenopausal osteoporosis, for example, alendronate treatment results in increases in bone mass and a reduction in fracture incidence, including at the hip.

Biochemical markers can predict the response in bone mass during alendronate treatment in early postmenopausal women. Alendronate Osteoporosis Prevention Study Group

Data from the Danish cohort (n = 67) of a multicenter trial of oral alendronate in the prevention of postmenopausal osteoporosis were used to evaluate the capacity of the biochemical markers to predict changes in bone mineral density (BMD). A panel of markers were measured: serum N-terminal midfragment osteocalcin (N-MID OC); serum total osteocalcin (total OC); bone-specific alkaline phosphatase (BSAP); serum and urine C-telopeptides of type I collagen (sCL and uCL); urine N-telopeptide crosslinks of type I collagen (NTX); and deoxypyridinoline (dPyr). The correlation between change from baseline at months 3-12 in total OC, N-MID OC, sCL, uCL, and NTX and 2 year response in spine BMD ranged from r = -0.45 to r = -0.78 (p < 0.001), and from r = -0.38 to r = 0.10 (n.s. to p < 0.002) for BSAP and dPyr. Sensitivity and specificity were used to assess the accuracy of change from baseline at month 6 in the biochemical markers for predicting prevention of bone loss in the spine over 2 years. The cutpoints used were a 30% (N-MID OC) or 50% (all other markers) decrease from baseline. Sensitivity levels were 82% (N-MID OC), 98% (total OC), 78% (sCL and NTX), and 89% (uCL). Specificities were 91% (N-MID OC), 59% (total OC), 100% (sCL), 71% (uCL), and 84% (NTX). Positive predictive values were 95% (N-MID OC), 82% (total OC), 100% (sCL), 87% (uCL), and 90% (NTX). In comparison, the predictive capacities of change from baseline at year 2 in hip BMD in predicting prevention of bone loss at the spine were similar: sensitivity, 82%; specificity, 55%; and positive predictive value, 79%. In conclusion, short-term changes in biochemical markers were valid predictors of long-term changes in BMD. Short-term changes in the sensitive biochemical markers revealed a predictive capacity similar to bone densitometry at the hip measured over 2 years. The sensitive biochemical markers offered a fast and valid alternative to bone densitometry for monitoring of alendronate treatment.

Increase of axial and appendicular trabecular and cortical bone density in established osteoporosis with intermittent nasal salmon calcitonin therapy

The aim of this study was to examine the effect of intranasal administration of salmon calcitonin to a group of 24 postmenopausal women with severe, established osteoporosis (t score < -2.5 SD) and more than one vertebral fracture. The patients were treated with 200 IU of nasal salmon calcitonin daily for 2 months with a subsequent pause of 2 months (3 cycles) and 500 mg calcium daily over a total of 12 months in an open randomized study. The patients were compared with an age matched control group of 18 women of a similar clinical status who were treated with calcium and vitamin D only. In the nasal calcitonin treatment group an increase in the trabecular axial bone density of 2.8% was achieved, as well as increase in trabecular appendicular (forearm) bone density of 1.6%, together with a cortical bone density increase of 1.8% axial and 1% appendicular. Initially, elevated values of urinary deoxypyridinoline were found in 12 women in the nasal calcitonin treatment group; these levels returned to normal under salmon calcitonin nasal therapy and documented the inhibition of increased osteoclastic activity. Cyclic intermittent calcitonin nasal therapy led to a general increase in trabecular and cortical axial and appendicular bone density, marked alleviation of the subjective sensation of pain, and a reduction in the daily dose of accompanying nonsteroidal anti-inflammatory drugs by 50%.

Intramuscular clodronate therapy in postmenopausal osteoporosis

Long-term daily administration of oral bisphosphonates has been effective in the treatment of postmenopausal osteoporosis, but the duration, mode and cost of the therapy may sometimes affect patient compliance. In Italy, the bisphosphonate clodronate is also available via the intramuscular (i.m.) route of administration, and the present study was performed to test its efficacy in postmenopausal osteoporosis. Ninety osteoporotic postmenopausal women were enrolled in a randomized, controlled 3 year study. The diet of all patients was adjusted to provide 1200-1300 mg of calcium daily, eventually by administration of supplements. Patients were randomly assigned to no therapy (30 patients) or to receive clodronate 100 mg i.m. either every 2 weeks (30 patients) or 1 week (30 patients). The i.m. injection caused substantial pain at the site of injection, which led to treatment withdrawal in almost 50% of the patients receiving weekly dosing. In control patients, a progressive, slow decline in spine and femoral bone mineral density (BMD), which became statistically significant at the end of the second year of observation, was observed. In the patients given weekly i.m. clodronate, spinal BMD rose by 3.8% (+/-7.3 SD) within 6 months. A slight, nonsignificant increase was observed thereafter, such that, at the completion of 3 years of observation, the mean gain was 4.5% (+/-6.3). In the patients treated with injections of 100 mg of clodronate every two weeks the increase in BMD was somewhat lower and slower, becoming significant only at month 24 (2.9+/-4.6%). In none of the two active groups was the femoral neck BMD changed significantly during the 3 years of the study. A significant increase in trochanter and Ward's triangle BMD was observed at month 12 only in the patients on the highest dose of clodronate. In both groups treated, the hip BMD changes were significantly different from those observed in control patients. The biochemical markers of bone turnover were suppressed in both clodronate groups. These results indicate that intermittent i.m. clodronate administration can provide clinically relevant benefits to skeletal bone density in osteoporotic postmenopausal women, but the in situ pain may limit its extensive use.