Effect of calcitonin on bone mass and fracture rates

Investigation of Bone Health Subsequent to Vitamin D Supplementation in Children Following Burn Injury

BACKGROUND

The effect of supplemental vitamin D on fracture occurrence following burn injuries is unclear. The objective of this study was to evaluate postintervention incidence of fractures in children during the rehabilitative phase postburn (PB) following participation in a randomized clinical trial of vitamin D supplementation.

MATERIALS AND METHODS

Follow-up for fracture evaluation was obtained in 39 of 50 patients randomized to daily enteral vitamin D2, D3, or placebo throughout the acute burn course. Serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, D2, D3, calcitonin, and bone alkaline phosphatase (BAP) measurements were obtained PB day 7, midpoint, discharge, and 1-year PB. Urinary calcium was obtained PB day 7 and midpoint. Dual-energy x-ray absorptiometry (DXA) was performed at discharge and 1-year PB.

RESULTS

Fractures were reported in 6 of 39 respondents. Four fractures occurred in the placebo group, 2 in the D2 group, and none in the D3 group. Serum vitamin D, calcitonin, BAP, and urinary calcium were similar between fracture groups. The group with fracture morbidity had larger burn size (83.8% ± 4.9% vs 53.0% ± 2.9%, P < .0001), greater full-thickness burn (69.7% ± 9.4% vs 39.4% ± 4.1%, P = .02), and increased incidence of inhalation injury (33% vs 6%, P = .04). Decreased bone mineral density z score was noted at discharge in the placebo fracture compared with no-fracture group (P < .05).

CONCLUSION

This preliminary report suggests there may be benefit of vitamin D3 in reducing postdischarge fracture risk. Results reaffirm the importance of monitoring bone health in pediatric patients postburn.

European guidance for the diagnosis and management of osteoporosis in postmenopausal women

Guidance is provided in a European setting on the assessment and treatment of postmenopausal women at risk of fractures due to osteoporosis.

INTRODUCTION

The International Osteoporosis Foundation and European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis published guidance for the diagnosis and management of osteoporosis in 2008. This manuscript updates these in a European setting.

METHODS

Systematic literature reviews.

RESULTS

The following areas are reviewed: the role of bone mineral density measurement for the diagnosis of osteoporosis and assessment of fracture risk, general and pharmacological management of osteoporosis, monitoring of treatment, assessment of fracture risk, case finding strategies, investigation of patients and health economics of treatment.

CONCLUSIONS

A platform is provided on which specific guidelines can be developed for national use.

Efficacy and harms of nasal calcitonin in improving bone density in young patients with inflammatory bowel disease: a randomized, placebo-controlled, double-blind trial

OBJECTIVES

There are very few published studies of agents having the potential to improve bone health in children with inflammatory bowel disease (IBD). The objective of this study was to establish the efficacy and safety of intranasal calcitonin in improving bone mineral density (BMD) in young patients with IBD and to define additional factors that impact bone mineral accrual.

METHODS

We conducted a randomized, placebo-controlled, double-blind clinical trial in 63 participants, ages 8-21 years, with a spinal BMD Z-score ≤ -1.0 s.d. measured by dual energy X-ray absorptiometry. Subjects were randomized to 200 IU intranasal calcitonin (n=31) or placebo (n=32) daily. All received age-appropriate calcium and vitamin D supplementation. Subsequent BMD measurements were obtained at 9 and 18 months.

RESULTS

Intranasal calcitonin was well tolerated. Adverse event frequency was similar in both treatment groups, and such events were primarily minor, reversible, and limited to the upper respiratory tract. The BMD Z-score change documented at screening and 9 months and screening and 18 months did not differ between the two therapeutic arms. In participants with Crohn's disease, the spinal BMD Z-score improved between screening and 9 months (change in spine BMD Z-score (ΔZSBMD)(9-0)) in the calcitonin group (ΔZSBMD(9-0)(calcitonin)=0.21 (0.37), ΔZSBMD(9-0)(placebo)=-0.15 (0.5), P=0.02); however, this was only a secondary subgroup analysis. Bone mineral accrual rate during the trial did not lead to normalization of BMD Z-score in this cohort. Factors favoring higher bone mineral accrual rate were lower baseline BMD and higher baseline body mass index Z-score, improvement in height Z-score, higher serum albumin, hematocrit and iron concentration, and more hours of weekly weight-bearing activity. Factors associated with lower bone mineral accrual rate were more severe disease-as indicated by elevated inflammatory markers, need for surgery, hospitalization, and the use of immunomodulators-and higher daily caffeine intake.

CONCLUSIONS

Intranasal calcitonin is well tolerated but does not offer a long-term advantage in youth with IBD and decreased BMD. Bone mineral accrual rate remains compromised in youth with IBD and low BMD raising concerns for long-term bone health outcomes. Improvement in nutritional status, catch-up linear growth, control of inflammation, increase in weight-bearing activity, and lower daily caffeine intake may be helpful in restoring bone density in children with IBD and low BMD.

European guidance for the diagnosis and management of osteoporosis in postmenopausal women

Guidance is provided in a European setting on the assessment and treatment of postmenopausal women with or at risk from osteoporosis.

INTRODUCTION

The European Foundation for Osteoporosis and Bone disease (subsequently the International Osteoporosis Foundation) published guidelines for the diagnosis and management of osteoporosis in 1997. This manuscript updates these in a European setting.

METHODS

The following areas are reviewed: the role of bone mineral density measurement for the diagnosis of osteoporosis and assessment of fracture risk; general and pharmacological management of osteoporosis; monitoring of treatment; assessment of fracture risk; case finding strategies; investigation of patients; health economics of treatment.

RESULTS AND CONCLUSIONS

A platform is provided on which specific guidelines can be developed for national use.

Osteoporosis

Effective therapies are available for the patient who has arthritic osteoporosis. The approach is critical to ensure an optimal quality of life in these individuals who suffer with a disease that is clearly treatable.

Osteoporosis

Bone is a complex organ which contains an organic matrix which serves as scaffolding, includes mineral as calcium distributed in a pattern providing structure and serves as an ion reservoir for the body. Throughout life it dynamically changes in response to changes in activity, body mass, and weight bearing. It is important to define patients at risk for bone loss, since accrued bone loss leading to osteoporosis in the older population of both men and women is unacceptable. There are many different therapies including biphosphonates which can decrease loss of bone and decrease fracture risk in patients who already have had sustained a fracture. Newer therapies such as parathyroid hormone may improve the fracture risk even more than biphosphonates over a shorter period of time.

Meta-analyses of therapies for postmenopausal osteoporosis. VI. Meta-analysis of calcitonin for the treatment of postmenopausal osteoporosis

OBJECTIVE

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

DATA SOURCE

We searched MEDLINE and EMBASE from 1966 to 2000 and examined citations of relevant articles and the proceedings of international osteoporosis meetings. We contacted osteoporosis investigators to identify additional studies and primary authors for unpublished data.

STUDY SELECTION

We included 30 studies that randomized women to calcitonin or an alternative (placebo or calcium and/or vitamin D) and measured bone density or fracture incidence for at least 1 yr.

DATA EXTRACTION

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

DATA SYNTHESIS

Calcitonin reduced the incidence of vertebral fractures, with a pooled relative risk (RR) of 0.46 [95% confidence interval (CI) 0.25-0.87, P = 0.02, n = 1404, 4 trials]. However, the RR from the one relatively large randomized controlled trial (RCT) was 0.79 (95% CI 0.62-1.00, P = 0.05, n = 1108). For nonvertebral fractures, the pooled RR was 0.52 (95% CI 0.22-1.23, P = 0.14, n = 1481, 3 trials). Once again, the single large trial showed a less impressive effect than the smaller trials (RR 0.80, 95% CI 0.59-1.09, P = 0.16, n = 1245). For bone density of the lumbar spine, the pooled weekly dose of 250 to 2800 IU per week resulted in significant increase in the weighted mean difference (WMD) of 3.74 (2.04-5.43, P < 0.01, n = 2260, 24 trials). The combined forearm showed a similar effect, with a WMD of 3.02 (95% CI 0.98-5.07, P < 0.01, n = 468, 9 trials). At the femoral neck, the pooled weighted mean difference showed a nonsignificant trend toward benefit, WMD 3.80 (95% CI -0.32-7.91, P = 0.07, 9 trials, n = 513). Methodologically weaker studies tended to show greater effects on bone density, and the lumbar spine results suggested the possibility of publication bias.

CONCLUSIONS

Calcitonin likely increases bone density in postmenopausal women predominantly at the lumbar spine and forearm for weekly doses of greater than 250 IU, although the true effect may be smaller than the pooled estimate would suggest. Calcitonin likely reduces the risk of vertebral fracture; its effect on nonvertebral fracture remains uncertain.

Cost effectiveness of nasal calcitonin in postmenopausal women: use of Cochrane Collaboration methods for meta-analysis within economic evaluation

OBJECTIVE

To assess the cost effectiveness of nasal calcitonin (Miacalcin) compared with no therapy, alendronate or etidronate in the treatment of postmenopausal women with previous osteoporotic fracture.

DESIGN AND SETTING

Meta-analysis followed by economic analysis.

PERSPECTIVE

A Canadian provincial Ministry of Health.

METHODS

The meta-analysis of randomised controlled clinical trials was based on the recommendations of the Cochrane Collaboration. Economic analysis was conducted within a Markov model using probabilities and costs derived from Canadian sources.

RESULTS

The meta-analysis found evidence of the positive effect of both nasal calcitonin and alendronate in reducing the risks of hip, wrist and vertebral fractures in postmenopausal women. However, there was a lack of evidence of the effect of etidronate on hip and wrist fractures. For a 65-year-old woman, with 5 years' therapy, the incremental cost per quality-adjusted life-year (QALY) gained for nasal calcitonin was 46,500 Canadian dollars ($Can) compared with no therapy and $Can32,600 compared with etidronate (1998 values). Comparison with alendronate was highly sensitive to the inclusion of one specific trial.

CONCLUSIONS

Given the results of the analysis, based on current evidence, nasal calcitonin can be considered at the margins of being cost effective when compared with no therapy. Compared with active therapy, nasal calcitonin can be considered more cost effective than etidronate, but its cost effectiveness versus alendronate is inconclusive.

Prevention and treatment of osteoporosis: efficacy of combination of hormone replacement therapy with other antiresorptive agents

Osteoporosis is a debilitating disease characterized by decreased bone mineral density (BMD) leading to fractures. It primarily affects postmenopausal women and elderly men. Prevention of osteoporosis is very important because present therapies do not have the potential to mend damage to the bone microarchitecture caused by osteoporosis. The first line of prevention and treatment of osteoporosis is hormone replacement therapy (HRT). All of the approved drugs for the prevention and treatment of osteoporosis act as inhibitors of bone resorption; these drugs include HRT, selective estrogen receptor modulators, calcitonin, and bisphosphonates. The latter two drugs have also been shown to prevent fractures. This article discusses data from nine controlled prospective clinical studies. Study 1 was designed to assess the efficacy of combined HRT and bisphosphonate in preventing osteoporosis during the early stages of menopause. This combined therapy increased the lumbar spine BMD by 10.9% and femoral BMD by 7.3% over 4 yr, compared with 6.8 and 4.0% with HRT alone, and 6.8 and 1.2% with bisphosphonate alone. Study 2 was conducted on postmenopausal women with established osteoporosis. These results showed a 10.4 and 7.0% increase in BMD in vertebrae and femora, respectively, compared with 7.3 and 4.8% increases in the HRT group, and 6.8 and 0.9% in the bisphosphonate group. Data from study 3 demonstrated similar findings in that the combination of alendronate and HRT also enhanced BMD values. Studies 4 and 5 assessed the efficacy of the combined therapy of HRT and calcitonin in the prevention of early postmenopausal bone loss. Both studies demonstrated a significant increase in BMD over and above that observed with either HRT or calcitonin alone. Studies 6, 7, and 8 demonstrated that the addition of testosterone to estrogen therapy further increased BMD when compared to estrogen therapy alone, and also prevented the expected decreases in markers of bone formation in early postmenopausal women. Study 9 demonstrated a synergistic effect on BMD in postmenopausal women, when HRT was coadministered with monofluorophosphate. Other combination therapies may also enhance BMD (e.g., the combination of alendronate and parathyroid hormone [PTH]). However, some agents either lose their efficacy or have no added effects on BMD when they are coadministered (e.g., tiludronate and PTH, calcitonin and PTH, calcitonin and anabolic steroids). These studies illustrate that in a subgroup of patients (i.e., patients with high bone turnover and/or severe osteoporosis), specific combination treatments such as HRT with bis-phosphonates, calcitonin, or androgens (and perhaps also with PTH, fluoride, nitric oxide donors) provide additional beneficial effects over a single-drug therapy. Whether these combination therapies are more effective than individual drugs in reducing fractures still needs to be determined.

Estimating the cost per avoided hip fracture by osteoporosis treatment in Italy

OBJECTIVES

A cost-effectiveness analysis on osteoporosis treatment has been carried out as the basis for an estimate of the cost per avoided hip fracture (CPAHF) in Italy.

METHODS

We have assumed as correct, reported data on the efficacy of calcitonin in preventing hip fractures in European women over 50 (Mediterranean Osteoporosis Study). Health-care costs were calculated using Weinstein and Stason's equation.

RESULTS

Given the incidence of such fractures in Italy and their cost to the health service, we calculate that in order to prevent one hip fracture 1285 women need to be treated with calcitonin at a cost of over two million dollars. The introduction of an element of screening (bone mass measurement to select a high risk subpopulation) would reduce the CPAHF by 65%. Choice of a more effective treatment (as the hormone replacement therapy) would be cost-neutral.

CONCLUSIONS

Drug-related costs, selection of high risk subpopulations and drug efficacy have important implications in the estimation of optimal CPAHF.

Salmon calcitonin nasal spray : An effective alternative to estrogen therapy in select postmenopausal women

The efficacy and safety of estrogen replacement therapy (ERT) and salmon calcitonin in the treatment of postmenopausal osteoporosis are reviewed with special consideration given to patients for whom ERT, the primary antiresorptive therapy for osteoporosis, is not indicated, tolerable, or is refused. The various formulations of estrogen and salmon calcitonin, for which the nasal spray formulation was recently approved for use in the United States, are reviewed in depth with reference to dose ranges, side effects, and convenience. Data regarding increases in bone mineral density (BMD) produced by each agent are presented. Specifically, the range of increases in BMD induced by ERT and salmon calcitonin are comparable. Given the substantial public health consequences of postmenopausal osteoporosis and osteoporotic fractures, the primary care physician is increasingly faced with the need to educated and recruit postmenopausal patients to appropriate therapy with the optimal agent for that particular patient. In the many patients who are unable or unwilling to accept, initiate, and comply with prescribed ERT, alternative therapeutic options are necessary Based on the established safety profile of salmon calcitonin, ease of administration, an uncomplicated dosing regimen, no reported drug interactions, and the lack of uterine bleeding associated with ERT or gastrointestinal adverse effects of other agents used to treat osteoporosis, salmon calcitonin nasal spray is an appropriate alternative approach for the treatment of postmenopausal bone loss.

Prevention of postmenopausal bone loss by rectal calcitonin

A group (150) of healthy women, who had been menopausal for less than 5 years and who had never received any form of treatment to prevent bone loss were entered into a randomized, controlled study comprising three arms. They were randomly allocated to the double-blind administration of five suppositories per week containing either 100 IU of salmon calcitonin or a placebo, or to a group receiving a suppository containing 200 IU of salmon calcitonin three times per week. All women received 500 mg/day of calcium supplementation. After 12 months, bone mineral density (BMD) of the spine, measured by dual energy X-ray absorptiometry, decreased significantly (P < 0.01) in the placebo group by 3.1% (SD: 3.6%) but did not change in the two calcitonin groups [+1.3% (3.5%) with 100 IU/day and +2.3% (4.0%) with 200 IU 3/week]. The differences in response between the placebo group and the two calcitonin groups were significant (P < 0.05), but the difference between the two regimens of calcitonin administration was not. No differences appeared among the three groups for the response at the level of the hip. Evolution of biochemical markers reflecting bone turnover did not differ significantly among groups. Nearly 40% of the women withdrew prematurely because of local (rectal or intestinal) intolerance to repetitive suppositories, with a nonsignificantly different frequency in the placebo or calcitonin groups. We conclude that rectal calcitonin might be an interesting preventive approach against trabecular postmenopausal bone loss but that long-term acceptability of suppositories should be evaluated in view of each patient's sensibility or cultural background.

A double-blind, placebo-controlled, dose-finding trial of intermittent nasal salmon calcitonin for prevention of postmenopausal lumbar spine bone loss

PURPOSE

Nasal administration of salmon calcitonin (SCT) has been suggested for preventing trabecular bone loss during the first years following the menopause, but no conclusive evidence has appeared about the minimal effective dose. Since nasal calcitonin is highly expensive, it makes sense to define this dose.

PATIENTS AND METHODS

We performed a double-blind, placebo-controlled, randomized, single-center study with a 3-arm parallel-group design. The subjects were 251 healthy women who had experienced natural menopause within the past 6 to 72 months and were not affected by any diseases or treatments that interfere with calcium metabolism. They were randomly allocated in groups of 6 to receive intranasal SCT 50 IU (n = 84), SCT 200 IU (n = 84), or placebo (n = 83). All treatments were given on 5 consecutive days per week. Statistical analysis was based on two populations: intention-to-treat (IT) and valid completers (VC). The main assessments performed were bone mineral density of the lumbar spine (LSBMD) and biochemical parameters reflecting bone turnover (serum alkaline phosphatase, urinary calcium/creatinine, and hydroxyproline/creatinine ratios).

RESULTS

Changes over the treatment period were comparable in the IT and VC populations. In the group receiving the placebo, LSBMD decreased from baseline to end point by a mean of 6.28% (95% confidence interval [CI] -7.69 to -4.89) in the IT population and 6.98% (95% CI -8.86 to -5.11) in the VC population (P = 0.0001, end LSBMD versus baseline LSBMD). LSBMD increased slightly with the 50-IU/d dose of SCT, by 0.82% (95% CI -0.26 to 1.89) in the IT population, and 0.51% (95% CI -0.69 to 1.72) in the VC (P = NS, versus baseline). Subjects who received SCT 200 IU/d experienced significant increases of 2.03% (95% CI 0.92 to 3.15) in the IT population and 2.26% (95% CI 1.01 to 3.51) in the VC (both P = 0.001). The difference between the evolution of the combined groups receiving nasal SCT and the group treated with the placebo was highly significant (P = 0.0001). No significant changes were recorded in biochemical parameters reflecting bone turnover.

CONCLUSIONS

SCT 50 IU/d administered nasally and intermittently appears to prevent lumbar bone loss in nonobese early postmenopausal women.

A 5-year controlled randomized study of prevention of postmenopausal trabecular bone loss with nasal salmon calcitonin and calcium

The aim of this paper was to evaluate the long-term (5 years) efficacy of nasal salmon calcitonin in prevention of trabecular postmenopausal bone loss, which was a follow-up of a previously published study (3 years); a randomized, controlled group comparison. One hundred healthy postmenopausal women were randomly chosen from those (186) having completed the 3 year protocol. The 100 women were allocated to an additional 2 year period (total of 5 years) of treatment with either 500 mg d-1, 5 days week-1 of calcium or the same amount of calcium plus 50 IU d-1, 5 days per week of nasal salmon calcitonin, 87 (87%) women complied with the protocol throughout. The main outcome measures were the bone mineral density of the lumbar spine (1-BMD) (DPA) and biochemical parameters reflecting bone turnover (serum alkaline phosphatases, urinary calcium/creatinine and hydroxyproline/creatinine ratios). The women receiving calcium alone presented a significant decrease in 1-BMD after 6 months [-1.6 (0.5)%] [mean(SEM)] (P < 0.01) and this decrease remained significant after 36 months [-6.1(0.8)%] (P < 0.01) and until the end of the trial [-6.6(1.0)% at t60] (P < 0.01). In women receiving calcium and calcitonin, 1-BMD significantly increased after 36 months [+2(0.7%] (P < 0.01) and 42 months [+2.5(0.7)%] (P < 0.01 and was unchanged at the other times of investigation [+1.1 (1.1)% at t60] (NS). The evolution of BMD in the two groups was highly significantly different (P < 0.001) since the sixth month of the study and remained so until the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitonin for prevention and treatment of osteoporosis

There appears to be a consensus that 100 IU/day of nasally administered salmon calcitonin may prevent trabecular bone loss during the first year of the menopause. Strong evidence exists that half that dose may also be sufficient to prevent trabecular bone loss and that higher doses (> or = 200 IU/day) induce a significant increase in spinal bone mineral content. Calcium supplements should be systemically administered when calcitonin is given, particularly at high doses. Rectal calcitonin seems also to be an efficient alternative in prevention of trabecular bone loss. Further studies are required to evaluate the effect of calcitonin in prevention of cortical bone loss. In established osteoporosis calcitonin may prevent further bone loss at trabecular and cortical sites. A similar benefit is obtained following parenteral or nasal administration of the drug. Long-term administration of nasal salmon calcitonin induces a significant dose-dependent gain of bone at the lumbar spine, whereas discontinuous therapy with a ratio of 1:2 or 2:3 between the treatment and nontreatment periods is the best regimen for cortical bone. Epidemiological, retrospective, and prospective studies provide a convergent network of evidence that calcitonin administration in osteoporosis contributes to reduce significantly the frequency of subsequent fractures, both in the spine and in the hip. Finally, in established osteoporosis, nasal calcitonin possesses a potent analgesic effect, reduces the duration of bed confinement, and decreases the number of concomitant analgesic medications. The well-demonstrated effects of nasal calcitonin permit it to be considered as a highly rational solution for the prevention and the treatment of postmenopausal osteoporosis.

Primary osteoporosis. Methods to combat bone loss that accompanies aging

Osteoporosis is a major public health problem in the United States. The key to its management is prevention by ensuring adequate amounts of calcium, vitamin D, and protein and exercise throughout life. When a significant amount of bone mass has been lost, therapeutic interventions are aimed at preventing further loss with use of antiresorptive agents (ie, estrogen, progestin, calcitonin, and bisphosphonates). Use of pharmacologic agents that stimulate bone formation is still in experimental stages. Research efforts focusing on prevention, diagnosis, and treatment of osteoporosis are in progress and should provide improved strategies in the future.

Sustained release of salmon calcitonin in vivo from lactide: glycolide copolymer depots

Studies were carried out to determine whether monolithic depot formulations, prepared using lactide:glycolide copolymers, could be used to administer salmon calcitonin (sCT) to rats in vivo. Formulations containing 2, 5, or 10% (w/w) sCT were administered subcutaneously to female Wistar strain rats. Release of sCT was determined by measurement of peptide in plasma using a specific radioimmunoassay and by measurement of residual sCT in the depots after recovery at postmortem. Plasma calcium concentrations and cumulative weight gain of the animals were used to measure pharmacological effects of the released sCT. Release of sCT from the depots was controlled by the copolymer and was sustained for periods up to 10 days. However, the release of sCT from the depots did not significantly alter plasma calcium concentrations, and effects on cumulative weight gain were small and transient. Peptide loading of the formulations was shown to modify sCT release. Maximal release of sCT from depots containing 10% peptide occurred over a 7 to 14-day period postadministration, with 5% sCT release occurred between days 11 and 14, and with 2% sCT, the period of maximal release was between days 11 and 18. Release of peptide from the depots was essentially complete by 21 days postadministration irrespective of the peptide loading. These data suggest that lactide:glycolide copolymer depots may have application for the convenient clinical administration of sCT in metabolic bone diseases.

Calcitonins: newer routes of delivery

Because of its anti-osteoclastic and analgesic properties, calcitonin is a first-line choice in the treatment of several bone diseases characterized by absolute or relative bone resorption. With regard to the prevention and treatment of postmenopausal osteoporosis, the chronic nature of the disease and the subsequent long duration of the pharmacological intervention require uncomfortable parenteral administration to be repeated on a long-term basis. Newer routes of administration have therefore been developed. At present the most promising of these are the nasal spray and the rectal suppository. Both routes have been shown to induce significant increases in plasma levels of salmon calcitonin. The ability of salmon calcitonin to cross the nasal mucosa was shown immunologically by the generation of specific anti-salmon-calcitonin antibodies in the plasma. In healthy volunteers these alternative routes of administration do not decrease the anti-osteoclastic activity of calcitonin, as demonstrated by a significant decrease in biochemical parameters that reflect bone turnover. In the prevention and treatment of postmenopausal osteoporosis, as well as in the treatment of Paget's disease of bone, the properties of calcitonins are generally preserved if they are administered non-parenterally. However, the equivalent doses required to sustain the effects of calcitonin have not been fully elucidated. This article reviews the potential benefits of two methods of non-parenteral administration of calcitonins in the prevention and treatment of postmenopausal osteoporosis.