Tolerability of risedronate in postmenopausal women intolerant of alendronate

Risedronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women

BACKGROUND

Osteoporosis is an abnormal reduction in bone mass and bone deterioration leading to increased fracture risk. Risedronate belongs to the bisphosphonate class of drugs which act to inhibit bone resorption by interfering with the activity of osteoclasts. This is an update of a Cochrane Review that was originally published in 2003.

OBJECTIVES

We assessed the benefits and harms of risedronate in the primary and secondary prevention of osteoporotic fractures for postmenopausal women at lower and higher risk for fractures, respectively.

SEARCH METHODS

With broader and updated strategies, we searched the Cochrane Central Register of Control Trials (CENTRAL), MEDLINE and Embase. A grey literature search, including the online databases ClinicalTrials.gov, International Clinical Trials Registry Platform (ICTRP), and drug approval agencies, as well as bibliography checks of relevant systematic reviews was also performed. Eligible trials published between 1966 to 24 March 2021 were identified.

SELECTION CRITERIA

We included randomised controlled trials that assessed the benefits and harms of risedronate in the prevention of fractures for postmenopausal women. Participants must have received at least one year of risedronate, placebo or other anti-osteoporotic drugs, with or without concurrent calcium/vitamin D. Major outcomes were clinical vertebral, non-vertebral, hip and wrist fractures, withdrawals due to adverse events, and serious adverse events. In the interest of clinical relevance and applicability, we classified a study as secondary prevention if its population fulfilled more than one of the following hierarchical criteria: a diagnosis of osteoporosis, a history of vertebral fractures, low bone mineral density (BMD)T score ≤ -2.5, and age ≥ 75 years old. If none of these criteria was met, the study was considered to be primary prevention.

DATA COLLECTION AND ANALYSIS

We used standard methodology expected by Cochrane. We pooled the relative risk (RR) of fractures using a fixed-effect model based on the expectation that the clinical and methodological characteristics of the respective primary and secondary prevention studies would be homogeneous, and the experience from the previous review suggesting that there would be a small number of studies. The base case included the data available for the longest treatment period in each placebo-controlled trial and a >15% relative change was considered clinically important. The main findings of the review were presented in summary of findings tables, using the GRADE approach. In addition, we looked at benefit and harm comparisons between different dosage regimens for risedronate and between risedronate and other anti-osteoporotic drugs.

MAIN RESULTS

Forty-three trials fulfilled the eligibility criteria, among which 33 studies (27,348 participants) reported data that could be extracted and quantitatively synthesized. We had concerns about particular domains of risk of bias in each trial. Selection bias was the most frequent concern, with only 24% of the studies describing appropriate methods for both sequence generation and allocation concealment. Fifty per cent and 39% of the studies reporting benefit and harm outcomes, respectively, were subject to high risk. None of the studies included in the quantitative syntheses were judged to be at low risk of bias in all seven domains. The results described below pertain to the comparisons for daily risedronate 5 mg versus placebo which reported major outcomes. Other comparisons are described in the full text. For primary prevention, low- to very low-certainty evidence was collected from four studies (one to two years in length) including 989 postmenopausal women at lower risk of fractures. Risedronate 5 mg/day may make little or no difference to wrist fractures [RR 0.48 ( 95% CI 0.03 to 7.50; two studies, 243 participants); absolute risk reduction (ARR) 0.6% fewer (95% CI 1% fewer to 7% more)] and withdrawals due to adverse events [RR 0.67 (95% CI 0.38 to 1.18; three studies, 748 participants); ARR 2% fewer (95% CI 5% fewer to 1% more)], based on low-certainty evidence. However, its preventive effects on non-vertebral fractures and serious adverse events are not known due to the very low-certainty evidence. There were zero clinical vertebral and hip fractures reported therefore the effects of risedronate for these outcomes are not estimable.  For secondary prevention, nine studies (one to three years in length) including 14,354 postmenopausal women at higher risk of fractures provided evidence. Risedronate 5 mg/day probably prevents non-vertebral fractures [RR 0.80 (95% CI 0.72 to 0.90; six studies, 12,173 participants); RRR 20% (95% CI 10% to 28%) and ARR 2% fewer (95% CI 1% fewer to 3% fewer), moderate certainty], and may reduce hip fractures [RR 0.73 (95% CI 0.56 to 0.94); RRR 27% (95% CI 6% to 44%) and ARR 1% fewer (95% CI 0.2% fewer to 1% fewer), low certainty]. Both of these effects are probably clinically important. However, risedronate's effects are not known for wrist fractures [RR 0.64 (95% CI 0.33 to 1.24); three studies,1746 participants); ARR 1% fewer (95% CI 2% fewer to 1% more), very-low certainty] and not estimable for clinical vertebral fractures due to zero events reported (low certainty). Risedronate results in little to no difference in withdrawals due to adverse events [RR 0.98 (95% CI 0.90 to 1.07; eight studies, 9529 participants); ARR 0.3% fewer (95% CI 2% fewer to 1% more); 16.9% in risedronate versus 17.2% in control, high certainty] and probably results in little to no difference in serious adverse events [RR 1.00 (95% CI 0.94 to 1.07; six studies, 9435 participants); ARR 0% fewer (95% CI 2% fewer to 2% more; 29.2% in both groups, moderate certainty).

AUTHORS' CONCLUSIONS

This update recaps the key findings from our previous review that, for secondary prevention, risedronate 5 mg/day probably prevents non-vertebral fracture, and may reduce the risk of hip fractures. We are uncertain on whether risedronate 5mg/day reduces clinical vertebral and wrist fractures.  Compared to placebo, risedronate probably does not increase the risk of serious adverse events.  For primary prevention, the benefit and harms of risedronate were supported by limited evidence with high uncertainty.

Risedronate's Role in Reducing Hip Fracture in Postmenopausal Women with Established Osteoporosis

Osteoporosis is a significant concern for postmenopausal women and is a critical factor in hip fracture. Examining evidence for osteoporosis medications in hip fracture is important for optimizing treatment.

PURPOSE

Review risedronate's role for hip fracture in postmenopausal women.

METHODS

A literature search was conducted using Medline and Web of Science. The search was limited using the terms "risedronate" and "hip fracture," and to studies that included women. Similar articles linked to the search and pertinent articles in bibliographies were also examined.

RESULTS

Risedronate has demonstrated efficacy and cost effectiveness for hip fracture, but may not be beneficial for patients with low fracture risk. Risedronate is generally well tolerated, but may cause side effects in some patient populations.

CONCLUSION

Risedronate has benefit for hip fracture, but patients should be carefully screened to determine the appropriateness of risedronate before starting treatment.

Safety of long-term bisphosphonate therapy for the management of osteoporosis

Drugs in the bisphosphonate class are the most commonly prescribed therapeutic agents for the treatment of osteoporosis. Prospective, randomized, placebo-controlled clinical trials have demonstrated efficacy in reducing fracture risk, with favourable safety profiles, in women with postmenopausal osteoporosis. However, long-term use in clinical practice has been associated with reports of undesirable events not previously recognized. These have included gastrointestinal intolerance, osteonecrosis of the jaw, atypical femur fractures, oesophageal cancer, atrial fibrillation and chronic musculoskeletal pain. Physicians must be alert to newly recognized safety concerns, understand the level of evidence supporting them and be able to effectively communicate the balance of expected benefit and potential risk to patients. Usually, post-marketing adverse events are first presented as case reports or observational studies with variable levels of supporting evidence for plausibility, pathophysiology and causality. Widespread coverage in the news media, which can be alarming to patients and their physicians, may not present a balanced view of the proven benefits, the uncertain risks of therapy and the relative magnitude of these events. There may be confusion about the risks associated with bisphosphonate use for the treatment of osteoporosis versus treatment of other conditions, such as cancer, which typically involves a very different patient population and different doses or frequency of drug administration. Often reports of possible adverse events do not provide information on the number of patients exposed to the drug in proportion to the reported adverse event, or do not describe the incidence of the adverse event in a comparator population not exposed to the drug. Gastrointestinal intolerance with oral bisphosphonates, and hypocalcaemia, acute phase reactions and renal toxicity with intravenous bisphosphonates are characterized by biological plausibility and demonstration of causality. Safety concerns with uncertain biological plausibility and unproven causality include osteonecrosis of the jaw, atypical femur fractures, oesophageal cancer and ocular inflammation. Suspected concerns that are unlikely to be causally related include atrial fibrillation and hepatotoxicity. When making the decision to use a bisphosphonate for the treatment of osteoporosis, the balance between benefit and potential risks according to clinical circumstances of each patient should be considered.

Differences in persistence, safety and efficacy of generic and original branded once weekly bisphosphonates in patients with postmenopausal osteoporosis: 1-year results of a retrospective patient chart review analysis

The objective of this study was to compare the changes on bone mineral density, and the effects on persistence and adverse events in patients treated for postmenopausal osteoporosis with generic alendronate or with branded alendronate (Fosamax®) or branded risedronate (Actonel®) once weekly. In this retrospective patient chart analysis, we reviewed the 1-year observational treatment results for 186 women (ITT population) with postmenopausal osteoporosis. Patients from our outpatient department, who had started with once-weekly bisphosphonate therapy between 36 and at least 12 months before this chart review, were included in this comparative three-arm study according to their treatment: A, Generic Alendonate 70 mg products; B, Branded Alendronate (Fosamax®) 70 mg once weekly and C, Branded Risedronate (Actonel®) 35 mg once weekly. All patients received basic therapy with 1,200 mg calcium and 800 IU vitamin D per day. Patient’s bone mineral density (BMD) at lumbar spine and total hip was below −2.5 T-score, and they were with or without prevalent vertebral and non-vertebral fractures. Data analysis regarding the 186 patients shows an average increase in LS-BMD after 12 months of 2.8, 5.2 and 4.8% for the groups A, B and C, respectively. The respective mean changes at total hip were 1.5, 2.9, and 3.1%. At both sites, the mean increases in BMD were not different between the two groups receiving branded bisphosphonates (B, C) but for both were significantly higher than for the group treated with generic alendronate (A). At 12 months, 68% of group A, 84% of group B and 94% of group C were still on bisphosphonate therapy. The persistence of patients treated with generic alendronate was significantly lower as compared to each of the two with branded bisphosphonate-treated groups. The total numbers of patients reporting gastrointestinal adverse events were 32, 15 and 9 for group A, group B, and group C, respectively. Significantly lower increases of lumbar spine and total hip BMD with generic alendronate once weekly as compared to the two branded bisphosphonate originals (Fosamax®, Actonel®) were observed. The reasons for the 40–50% lower BMD increase rates when using the generic compounds are not known yet. At least in part the lower efficacy can be explained by a significantly lower degree of persistence with generic alendronate, which could be related to a higher incidence of gastrointestinal adverse events. Other reasons could be lower bioavailability or potency of generic alendronate.

Bisphosphonates for the treatment of osteoporosis: insights for clinicians

Osteoporosis is a common skeletal disease characterized by a reduction in bone strength and increased risk of fractures. Osteoporotic fractures are associated with substantial morbidity, mortality, and high healthcare costs. Treatments for osteoporosis have been shown to increase bone strength and reduce fracture risk. The drugs most commonly used to treat osteoporosis are bisphosphonates: stable analogs of naturally occurring inorganic pyrophosphate. The bisphosphonates share a common chemical structure with side chain variations that convey differences in their pharmacological properties, such as affinity for bone mineral and inhibitory effect on osteoclastic bone resorption. The clinical profiles of bisphosphonates, such as time of onset and offset of effect, may differ according to these pharmacological properties. Bisphosphonates can be administered orally or intravenously with a wide range of doses and dosing intervals. Randomized placebo-controlled clinical trials have shown that bisphosphonates reduce fracture risk in postmenopausal women with osteoporosis and have a generally excellent safety record. Clinical challenges in using bisphosphonates to treat osteoporosis include appropriate selection of patients for initiating therapy, choosing which bisphosphonate to use, monitoring therapy to assure that medication is taken correctly and the desired effect is achieved, determining when drug discontinuation should be considered, and managing side effects, possible side effects, and fear of side effects. Strategies for treating patients with bisphosphonates should consider each of these issues.

Oral ibandronate in the management of postmenopausal osteoporosis: Review of upper gastrointestinal safety

Oral daily bisphosphonates carry a potential for gastrointestinal (GI) adverse events, which has been partly addressed by introducing once-weekly regimens. Nevertheless, the need to follow inconvenient dosing instructions every week could still hinder long-term compliance and therapeutic outcome. In addition, survey data indicates that many patients would prefer a once-monthly rather than once-weekly bisphosphonate dosing regimen. Ibandronate is a potent, nitrogen-containing bisphosphonate specifically developed for less frequent administration. In a pivotal study in postmenopausal osteoporosis, oral ibandronate, administered daily or with a between-dose interval of >2 months, demonstrated robust antifracture efficacy and an overall incidence of upper GI adverse events similar to placebo, even in patients at increased risk of such events. This and other clinical studies conducted in postmenopausal women demonstrate that oral ibandronate has an excellent upper GI safety profile.

Pharmacotherapy of osteoporosis in postmenopausal women: focus on safety

The therapy of osteoporosis has made enormous strides in the last decade. There is now a range of interventions, each with its pros and cons. Calcium and vitamin D supplementation remain the foundation and have few safety issues. Bisphosphonates are widely used, though gastrointestinal tolerance is a problem with some oral preparations. Intravenous administration may circumvent this, although this introduces the smaller problem of acute phase reactions. The side effect profile of hormone replacement therapy (HRT) is still being delineated after 40 years of use, with substantial new information expected in the next few years. This will clarify its place in the medical management of the menopause. Raloxifene appears to have a superior safety profile to HRT, though its efficacy on bone may be less. While none of these options is suitable for everyone, the range of available therapies does mean that most patients can find an intervention that is effective and acceptable.