Risedronate
Indications
| Indication | Approved Population | Formulation | Status |
|---|---|---|---|
| Postmenopausal osteoporosis — treatment | Postmenopausal women; reduces vertebral fracture incidence and a composite endpoint of nonvertebral osteoporosis-related fractures | Actonel (IR) and Atelvia (DR) | FDA Approved |
| Postmenopausal osteoporosis — prevention | Postmenopausal women | Actonel (IR) only — Atelvia is not approved for prevention | FDA Approved |
| Increase bone mass in men with osteoporosis | Men with osteoporosis | Actonel (IR) only | FDA Approved |
| Glucocorticoid-induced osteoporosis — treatment AND prevention | Men and women initiating or continuing systemic glucocorticoid treatment ≥7.5 mg prednisone-equivalent daily for chronic disease (FDA labelling does not require demonstration of low BMD for this indication) | Actonel (IR) only | FDA Approved |
| Paget’s disease of bone | Men and women with Paget’s disease | Actonel (IR) only | FDA Approved |
The current FDA labelling notes that the optimal duration of use for osteoporosis has not been determined and that drug discontinuation should be considered after 3 to 5 years of use in patients at low fracture risk. Risedronate is one of the agents endorsed as first-line oral therapy for postmenopausal osteoporosis by AACE/ACE 2020 and Endocrine Society 2019 guidelines, with selection often based on patient tolerability, dosing flexibility, and cost. Compared with alendronate, the FDA-labelled glucocorticoid-induced osteoporosis indication for risedronate is broader: it covers both treatment and prevention and does not require demonstration of low BMD for eligibility. The Atelvia delayed-release formulation is approved only for treatment (not prevention) of postmenopausal osteoporosis and is taken differently from immediate-release risedronate (after breakfast rather than fasting).
Cancer treatment-induced bone loss (aromatase inhibitor or androgen-deprivation therapy) — used to attenuate BMD decline; evidence quality: moderate for BMD endpoints. Denosumab and zoledronic acid have stronger fracture-outcome data and are preferred in oncology guidelines.
Osteogenesis imperfecta in children — sometimes used in pediatric subspecialty practice. Evidence quality: low. The FDA-reviewed pediatric study of 143 children (94 receiving risedronate) with predominantly mild OI showed an increase in lumbar spine BMD but did not reduce fracture risk. Adverse event rates exceeding placebo at ≥10%: pain in extremity (21% vs 16%), headache (20% vs 8%), back pain (17% vs 10%), pain (15% vs 10%), upper abdominal pain (11% vs 8%), bone pain (10% vs 4%); vomiting was 15% versus 6% on placebo. IV pamidronate or zoledronic acid are more commonly used.
Fibrous dysplasia of bone — used to reduce bone pain and turnover markers; evidence quality: very low (case series, no randomized data specifically for risedronate).
Hypercalcemia of malignancy — oral bisphosphonates are not appropriate for this indication because of poor and variable absorption; IV zoledronic acid or pamidronate are standard of care.
Dosing
Risedronate offers more dosing flexibility than other oral bisphosphonates, with daily, weekly, twice-monthly, and monthly regimens for postmenopausal osteoporosis. All immediate-release oral dosing requires fasting administration with plain water and 30 minutes upright. The delayed-release formulation (Atelvia) is taken differently — see the dedicated section below. Doses below assume normal renal function (CrCl ≥30 mL/min).
Immediate-Release Risedronate (Actonel and Generics)
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| Postmenopausal osteoporosis — treatment | 35 mg PO once weekly | 35 mg once weekly | 150 mg/month equivalent | Four equivalent regimens approved Alternatives: 5 mg PO daily; 75 mg on two consecutive days monthly; 150 mg PO once monthly |
| Postmenopausal osteoporosis — prevention | 35 mg PO once weekly | 35 mg once weekly | 150 mg/month equivalent | 5 mg PO daily is the alternative; the FDA labelling notes that 75 mg twice-monthly or 150 mg monthly may also be considered as alternative regimens |
| Increase bone mass in men with osteoporosis | 35 mg PO once weekly | 35 mg once weekly | 35 mg/week | Only the weekly regimen is FDA-approved in this indication |
| Glucocorticoid-induced osteoporosis — treatment and prevention | 5 mg PO once daily | 5 mg once daily | 5 mg/day | Indicated at glucocorticoid doses ≥7.5 mg prednisone-equivalent daily for chronic disease; ensure adequate calcium and vitamin D intake |
| Paget’s disease of bone | 30 mg PO once daily | 30 mg once daily × 2 months | 30 mg/day | Re-treatment may be considered after a ≥2-month post-treatment observation period if relapse occurs or alkaline phosphatase fails to normalize No data are available on more than one course of re-treatment |
Delayed-Release Risedronate (Atelvia)
| Clinical Scenario | Dose | Administration | Notes |
|---|---|---|---|
| Postmenopausal osteoporosis — treatment only (not approved for prevention) | 35 mg PO once weekly | After breakfast, in the morning, swallowed whole with at least 4 oz plain water; remain upright for 30 minutes | The delayed-release coating allows administration after food, unlike all other oral bisphosphonates Atelvia and Actonel must NOT be used together — same active ingredient. Per the FDA Atelvia labelling, this is an explicit warning |
Renal Dose Adjustment
| Renal Function | Recommendation | Notes |
|---|---|---|
| CrCl ≥30 mL/min | Standard dose | No dosage adjustment required per FDA PI |
| CrCl <30 mL/min | Not recommended | Renal clearance of risedronate decreased by approximately 70% in patients with CrCl ~30 mL/min; lack of clinical experience below this threshold |
Special Populations
- Hepatic impairment: No dosage adjustment required (risedronate is not metabolized; biliary excretion of an IV dose is <0.1% in animal studies).
- Older adults (≥65 years): No dosage adjustment required. Bioavailability and disposition are similar in elderly versus younger subjects per FDA PI; renal function should be reviewed before initiation.
- Pediatrics: Not indicated. The FDA-reviewed 1-year pediatric osteogenesis imperfecta study did not demonstrate fracture-risk reduction.
- Long-term therapy and drug holiday: The FDA labelling recommends reassessment for drug discontinuation after 3 to 5 years of use in patients at low fracture risk.
Immediate-release risedronate (Actonel) follows the standard oral bisphosphonate routine: take on first waking, fasting, with a full glass (6 to 8 oz) of plain water, and remain upright for at least 30 minutes before any food, beverage, or other medication. Delayed-release risedronate (Atelvia) is unique among oral bisphosphonates: take in the morning immediately after breakfast with at least 4 oz of plain water, then remain upright for 30 minutes. Both forms must be swallowed whole; do not chew, cut, or crush. Patients should never receive both Actonel and Atelvia concurrently.
Pharmacology
Mechanism of Action
Risedronate is a pyridinyl bisphosphonate that binds with high affinity to hydroxyapatite at sites of active bone remodeling. As a nitrogen-containing bisphosphonate, it inhibits farnesyl pyrophosphate synthase in the mevalonate pathway within osteoclasts, blocking prenylation of small GTPases (Ras, Rho, Rac) required for osteoclast cytoskeletal organization, ruffled-border formation, and survival. The result is reduced osteoclast activity and increased osteoclast apoptosis, which decreases bone resorption.
At the cellular level, osteoclasts adhere normally to bone surfaces but show evidence of reduced active resorption (lack of ruffled border). Histomorphometric studies in animals confirm reduced bone-turnover activation frequency without disruption of mineralization or histologically abnormal bone. Bone formation eventually decreases as the resorption-formation coupling re-equilibrates, but net positive bone balance during the early treatment period yields measurable BMD gains within 6 months at the lumbar spine and hip.
ADME Profile
| Parameter | Value | Clinical Implication |
|---|---|---|
| Absorption | Oral bioavailability ~0.63% (immediate-release, fasted); independent of dose strength (5–30 mg) and bioequivalent between tablet and aqueous solution. Tmax approximately 1 hour. Food and divalent cations markedly reduce absorption of immediate-release; the delayed-release formulation is designed to release in the small intestine after breakfast | Strict fasting administration with plain water is mandatory for immediate-release; delayed-release allows post-breakfast administration; bioavailability is the primary modifiable determinant of efficacy |
| Distribution | Steady-state Vd ~13.8 L/kg in humans; ~24% plasma protein binding (low compared with alendronate). In preclinical rat and dog IV studies with [14C]-risedronate, approximately 60% of the dose distributed to bone with the remainder excreted in urine; analogous human radio-labelled distribution data are not available, but human PK is consistent with high skeletal affinity | Lower protein binding than alendronate; rapid bone uptake; minimal soft-tissue distribution |
| Metabolism | Not metabolized in animals or humans; no CYP450 induction or inhibition; biliary excretion is <0.1% of an IV dose (animal data) | No clinically significant pharmacokinetic drug-drug interactions via hepatic pathways |
| Elimination | Renal excretion of unchanged drug; in healthy subjects, mean renal clearance ~105 mL/min and total clearance ~122 mL/min, with renal clearance accounting for ~87% of total clearance after IV dosing; approximately half of an absorbed oral dose excreted in urine within 24 hours; 65% of an IV dose excreted in 24 hours and 85% over 28 days; initial half-life ~1.5 h, terminal half-life ~480 hours (~20 days). In osteopenic postmenopausal women, mean total clearance is ~73 mL/min, partly reflecting age-related renal decline | Avoid in CrCl <30 mL/min; pharmacologic effect wanes more rapidly than alendronate after discontinuation, although fracture risk reduction has been shown to persist for at least 1 year off-therapy in post-trial follow-up of randomized trial participants (Watts 2008) |
Side Effects
Adverse-event rates below derive from the FDA prescribing information Table 1: combined Phase 3 postmenopausal osteoporosis treatment trials of risedronate 5 mg daily versus placebo (n=1,613 risedronate, n=1,619 placebo, 3-year duration). Events shown are reported regardless of causality. The overall safety profile of risedronate was similar to placebo, with a numerically lower rate of withdrawal due to adverse events with risedronate (14.8% versus 15.6%). Per the FDA highlights, the four most common adverse reactions reported in >10% of patients and at a higher frequency than placebo were back pain, arthralgia, abdominal pain, and dyspepsia.
| Adverse Event | Risedronate vs Placebo | Clinical Note |
|---|---|---|
| Infection (general, all types) | 31.1% vs 29.9% | Numerically similar to placebo; no specific risedronate-related infection signal |
| Back pain | 28.0% vs 26.1% | One of the four most common drug-related events per the FDA highlights; numerically similar to placebo in absolute terms |
| Arthralgia | 23.7% vs 22.1% | One of the four most common drug-related events per the FDA highlights; numerically similar to placebo |
| Accidental injury | 16.9% vs 16.8% | Equivalent to placebo |
| Pain (general) | 14.1% vs 14.0% | Equivalent to placebo |
| Constipation | 12.9% vs 12.6% | Numerically similar to placebo |
| Abdominal pain | 12.2% vs 9.9% | One of the four most common drug-related events per the FDA highlights; absolute difference 2.3 percentage points |
| Urinary tract infection | 11.1% vs 10.4% | Numerically similar to placebo |
| Diarrhea | 10.8% vs 10.0% | Numerically similar to placebo |
| Dyspepsia | 10.8% vs 10.6% | One of the four most common drug-related events per the FDA highlights; equivalent to placebo |
| Nausea | 10.5% vs 11.2% | Numerically lower than placebo |
| Hypertension | 10.5% vs 9.8% | Numerically similar to placebo |
| Flu syndrome | 10.5% vs 11.6% | Numerically lower than placebo |
| Bronchitis | 10.0% vs 10.4% | Numerically lower than placebo |
| Adverse Event | Risedronate vs Placebo | Clinical Note |
|---|---|---|
| Headache | 9.9% vs 10.8% | Numerically lower than placebo |
| Arthritis | 9.6% vs 10.1% | Numerically similar to placebo |
| Traumatic bone fracture | 9.3% vs 12.3% | Lower with risedronate — consistent with the antifracture efficacy demonstrated in VERT trials |
| Sinusitis | 8.7% vs 9.1% | Numerically lower than placebo |
| Rash | 7.9% vs 7.1% | Numerically similar to placebo; severe skin reactions are post-marketing reports |
| Peripheral edema | 7.7% vs 8.8% | Numerically lower than placebo |
| Dizziness | 7.1% vs 5.7% | Modestly higher than placebo (1.4 percentage-point difference) |
| Joint disorder | 7.0% vs 5.3% | Modestly higher than placebo |
| Depression | 6.8% vs 6.1% | Numerically similar to placebo |
| Myalgia | 6.7% vs 6.2% | Numerically similar to placebo |
| Cataract | 6.5% vs 5.7% | Reflects age-related background incidence |
| Rhinitis | 6.2% vs 5.1% | Numerically similar to placebo |
| Pharyngitis | 6.0% vs 5.0% | Numerically similar to placebo |
| Increased cough | 5.9% vs 6.3% | Numerically lower than placebo |
| Asthenia | 5.4% vs 4.5% | Numerically similar to placebo |
| Neck pain | 5.4% vs 4.7% | Numerically similar to placebo |
| Bone pain | 5.3% vs 4.8% | Numerically similar to placebo; severe musculoskeletal pain is a separate post-marketing concern |
| Insomnia | 5.0% vs 4.6% | Numerically similar to placebo |
| Chest pain | 5.0% vs 5.1% | Equivalent to placebo |
| Acute-phase reaction — 75 mg twice-monthly regimen | 7.6% vs 3.6% with 5 mg daily | Symptoms within 5 days of the first dose, generally self-limited; comparator was 5 mg daily, not placebo |
| Acute-phase reaction — 150 mg once-monthly regimen | 5.2% vs 1.1% with 5 mg daily | Symptoms within 3 days of the first dose for ≤7 days; comparator was 5 mg daily, not placebo |
| Adverse Effect | Estimated Frequency | Typical Onset | Required Action |
|---|---|---|---|
| Severe esophagitis, esophageal erosion, ulcer, stricture, or perforation; gastric or duodenal ulcers | Rare (post-marketing) | Days to months | Discontinue; urgent upper endoscopy if dysphagia, odynophagia, retrosternal pain, or new/worsening heartburn |
| Osteonecrosis of the jaw (ONJ) | Rare (post-marketing); generally associated with tooth extraction or local infection with delayed healing | Months to years; risk may increase with cumulative bisphosphonate exposure | Pre-treatment dental exam in high-risk patients; refer to oral-maxillofacial surgeon if exposed bone develops |
| Atypical low-energy or low-trauma femoral shaft fracture (subtrochanteric or diaphyseal); atypical fractures of other bones also reported | Rare; risk increases with bisphosphonate duration; may be bilateral | Often after >3 years of therapy; prodromal dull aching thigh pain weeks to months before complete fracture | Discontinue; image affected and contralateral femur; orthopedic referral; reassess risk/benefit and consider drug interruption |
| Severe and occasionally incapacitating bone, joint, or muscle pain | Rare (post-marketing); rates were similar to placebo in randomized trials | One day to several months after starting therapy | Discontinue; most patients have relief after stopping; do not rechallenge given recurrence risk |
| Symptomatic hypocalcemia | Rare; in daily-dosing trials mean changes from baseline were small (<1% in serum calcium, <3% in serum phosphate, <30% increase in PTH within 6 months); month-1 hypocalcemia incidence: 4.5% with 75 mg twice-monthly vs 3% with 5 mg daily; 2.2% with 150 mg monthly vs 0.2% with 5 mg daily | First month of therapy; particularly with monthly regimens | Verify and correct calcium and vitamin D before initiation; risk highest in CKD, vitamin D deficiency, hypoparathyroidism, or Paget’s disease with high bone turnover |
| Hypersensitivity reactions: angioedema, generalized rash, bullous skin reactions, Stevens-Johnson syndrome, toxic epidermal necrolysis | Rare (post-marketing) | Hours to weeks | Discontinue immediately; emergency care for airway involvement or skin sloughing |
| Eye inflammation: iritis, uveitis | Rare (post-marketing); reported in supportive Paget’s disease studies | Days to months | Discontinue and refer to ophthalmology for any new ocular pain, redness, photophobia, or visual change |
| Population / Regimen | Discontinuation Rate | Context |
|---|---|---|
| 5 mg daily vs 35 mg weekly (1-year head-to-head) | 11.9% vs 11.5% | Equivalent tolerability profiles between regimens |
| 5 mg daily vs 75 mg twice-monthly (2-year) | 14.2% vs 13.0% | Higher discontinuation due to vomiting (1.0% vs 0.2%) and diarrhea (1.0% vs 0.3%) with twice-monthly dosing, mostly within a few days of dosing |
| 5 mg daily vs 150 mg monthly (1-year) | 9.5% vs 8.6% | Higher discontinuation due to upper abdominal pain (2.5% vs 1.4%) and diarrhea (0.8% vs 0%) with monthly dosing, all events within a few days of the first dose |
| Glucocorticoid-induced osteoporosis (5 mg daily, 1-year, pooled treatment + prevention studies) | 7.5% vs 8.8% placebo | Lower withdrawal than placebo; higher reporting of arthralgia (24.7% vs 14.7%) and back pain (17.8% vs 8.8%) compared with placebo |
| Paget’s disease (30 mg/day × 2 months) vs etidronate (Didronel) | 6.6% vs 8.2% | Comparable AE-driven discontinuation rates between agents |
The 75 mg twice-monthly and 150 mg once-monthly regimens are associated with higher rates of an acute-phase reaction (flu-like symptoms, fever, myalgia, fatigue) than daily dosing — incidence approximately 7.6% with 75 mg twice-monthly and 5.2% with 150 mg monthly versus 3.6% and 1.1% respectively with 5 mg daily comparators. Symptoms occur within 3–5 days of the first dose and are generally self-limited; per FDA labelling these incidence figures are based on reporting of any of 33 acute-phase reaction-like symptoms within the early post-dose window. Counsel patients on the possibility of a transient flu-like reaction and recommend acetaminophen if needed. If significant, switching to weekly or daily dosing usually resolves recurrence.
Drug Interactions
Risedronate is not metabolized by CYP450 enzymes and has no clinically significant pharmacokinetic interactions through hepatic pathways. The dominant interaction mechanism is reduced gastrointestinal absorption from chelation with divalent cations or interference with the absorption mechanism. Of note, the delayed-release formulation (Atelvia) has a broader interaction profile than immediate-release risedronate because acid-suppressing drugs (PPIs, H2 blockers) can disrupt the pH-dependent enteric coating; the Atelvia FDA labelling explicitly lists PPIs, H2 blockers, magnesium-based supplements or laxatives, and iron preparations as agents that interfere with absorption, in addition to calcium and antacids.
Clinical references describe additional theoretical interactions with sodium bicarbonate, sodium citrate, and other oral medications that affect gastric pH or contain divalent cations. These are extensions of the absorption-interaction principle rather than independent pharmacokinetic interactions. The general rule for immediate-release risedronate is to take it on an empty stomach with plain water and to defer all other oral medications and supplements for at least 30 minutes.
Monitoring
Monitoring focuses on confirming therapeutic response, ensuring safe long-term exposure, and recognizing the predictable adverse events of bisphosphonate therapy. Recommendations below combine FDA labelling guidance with current AACE/ACE 2020 and ASBMR Task Force 2016 consensus.
-
Bone mineral density (DEXA)
Baseline, then every 1–2 years per guideline practice
Routine Lumbar spine and total hip / femoral neck T-scores. BMD increases at the spine and hip are detectable within 6 months of starting risedronate. Significant decline (beyond least significant change) warrants adherence assessment, secondary cause evaluation, and possible therapy switch. -
Serum calcium
Baseline; recheck at month 1 if monthly regimen used; recheck if symptomatic
Routine FDA labelling requires hypocalcemia to be corrected before initiation. Phase 3 trials showed mean changes from baseline in serum calcium of less than 1% and in serum phosphate of less than 3% within 6 months on daily dosing. The 75 mg twice-monthly regimen produced a slightly higher first-month hypocalcemia incidence (4.5% vs 3% with daily dosing) and the 150 mg monthly regimen produced 2.2% vs 0.2% with daily dosing in the respective head-to-head trials. Monitor more closely in CKD, vitamin D deficiency, hypoparathyroidism, or Paget’s disease. -
25-OH vitamin D
Baseline; periodic reassessment per individual risk
Routine All Phase 3 risedronate trials provided 1,000 mg elemental calcium daily, with vitamin D supplementation as needed. Replete deficiency before starting therapy. -
Serum creatinine / eGFR
Baseline; reassess with intercurrent illness or new nephrotoxic exposure
Routine FDA PI: risedronate is not recommended in CrCl <30 mL/min. No dosage adjustment in CrCl ≥30 mL/min. Renal clearance of risedronate is reduced ~70% at CrCl ~30 mL/min. -
Serum alkaline phosphatase (Paget’s disease)
Baseline and periodically during/after 2-month treatment course
Trigger-based FDA PI specifies that serum alkaline phosphatase should be measured periodically to assess response and detect relapse. Re-treatment may be considered after a ≥2-month post-treatment observation period if the level fails to normalize or rises again. -
Bone turnover markers (CTX, P1NP)
Optional; baseline and 3–6 months after initiation if used
Trigger-based Not part of FDA-labelled monitoring but used in some practices to confirm pharmacologic effect and adherence early. A meaningful drop from baseline supports adequate response. -
Dental examination
Pre-treatment in high-risk patients; routine dental care during therapy
Trigger-based FDA PI lists invasive dental procedures, cancer diagnosis, concomitant chemotherapy/corticosteroids/anti-angiogenic therapy, poor oral hygiene, and pre-existing dental disease as ONJ risk factors. Pre-treatment dental assessment is advisable in these populations. Routine dental care does not require interruption of risedronate. -
Femoral fracture screening
If new thigh, hip, or groin pain
Trigger-based Per the FDA Warnings and Precautions, any patient with bisphosphonate exposure presenting with thigh or groin pain should be evaluated to rule out an incomplete femur fracture. Image bilateral femurs; assess for atypical features. Risk/benefit of continuing therapy should be reassessed. -
Fracture risk reassessment for drug holiday
After 3 to 5 years of continuous oral therapy
Routine FDA labelling: patients at low fracture risk should be considered for drug discontinuation after 3 to 5 years; reassess fracture risk periodically thereafter. Because risedronate has a much shorter terminal half-life than alendronate, the residual antiresorptive effect after discontinuation may be shorter, but observational follow-up has shown persistent fracture risk reduction at least 1 year off therapy. -
Adherence and administration technique
Every visit
Routine For immediate-release: timing relative to food, water volume, upright posture, fasting interval. For Atelvia: confirm patient takes the tablet AFTER breakfast (opposite of usual bisphosphonate routine). Verify the patient is not taking both Actonel and Atelvia.
Contraindications & Cautions
Absolute Contraindications (per FDA prescribing information)
- Abnormalities of the esophagus that delay esophageal emptying — including stricture or achalasia.
- Inability to stand or sit upright for at least 30 minutes.
- Hypocalcemia — must be corrected before initiation.
- Known hypersensitivity to risedronate or any component of the product — angioedema, generalized rash, bullous skin reactions, Stevens-Johnson syndrome, and toxic epidermal necrolysis have been reported.
- Concurrent use of Actonel and Atelvia — they contain the same active ingredient; the FDA Atelvia labelling specifies that patients on Actonel must not receive Atelvia and vice versa.
Use Not Recommended (Specialist Input Advised)
- Severe renal impairment (CrCl <30 mL/min) — not recommended per FDA PI due to lack of clinical experience.
- Active upper GI disease — Barrett’s esophagus, dysphagia, other esophageal diseases, gastritis, duodenitis, or ulcers — caution per FDA Warnings; defer until controlled or use alternative agent.
- Recent or planned invasive dental procedure in patients with additional ONJ risk factors (current or prior IV bisphosphonates, glucocorticoids, anti-angiogenic therapy, head and neck radiation, cancer diagnosis); defer initiation if feasible.
- Pregnancy or planned pregnancy — discontinue when pregnancy is recognized per FDA PI; bisphosphonates persist in bone, and animal data have shown reduced neonatal survival, decreased pup body weight, low incidence of cleft palate, and delayed skeletal ossification at doses approaching or exceeding the human Paget’s disease dose.
- History of atypical femoral fracture — strong relative contraindication; alternative agents preferred (denosumab, teriparatide).
Use with Caution
- Concurrent NSAIDs, aspirin, or systemic glucocorticoids — additive GI risk and (with glucocorticoids) atypical femoral fracture risk noted in FDA labelling.
- Older adults with frailty, dementia, or aspiration risk — assess capacity to follow administration instructions.
- Long-term therapy (>3 to 5 years) — reassess need at this interval per FDA labelling.
- Patients with poor dentition or active oral infection — address with dental team before or during therapy.
- Patients on chronic PPI or H2-blocker therapy — prefer immediate-release Actonel over Atelvia, since acid suppression disrupts the delayed-release coating.
The FDA issued a Drug Safety Communication on October 13, 2010, requiring a class-wide Warning regarding atypical low-energy or low-trauma fractures of the femoral shaft (subtrochanteric and diaphyseal) in patients on bisphosphonates approved for osteoporosis. The Warnings and Precautions section was updated again in February 2026 to clarify that atypical fractures of bones other than the femur have also been reported, that they may be bilateral, and that they can occur in osteoporotic patients who have not been treated with bisphosphonates. Concomitant glucocorticoid use may also induce these fractures.
Prodromal pain in the affected area, usually presenting as dull, aching thigh pain weeks to months before a complete fracture, was reported by many patients. Any patient with a history of bisphosphonate exposure who presents with thigh or groin pain should be evaluated to rule out an incomplete femur fracture. Risk/benefit of continuing bisphosphonate therapy should be re-evaluated, and interruption of therapy should be considered. Osteonecrosis of the jaw and severe musculoskeletal pain are also recognized class-wide warnings; routine dental care should be maintained during therapy.
Patient Counselling
Purpose of Therapy
Explain that risedronate strengthens bone over months to years by reducing the rate at which old bone is removed. The medication does not reverse osteoporosis overnight; the goal is to prevent fractures, particularly of the spine and hip. In the VERT trials, risedronate 5 mg daily reduced the risk of new vertebral fractures by approximately 41–49% over 3 years and produced measurable bone-density improvement within 6 months. Most patients will not feel any difference day-to-day, which is normal. Adherence to the chosen regimen for years, combined with adequate dietary calcium and vitamin D, is what produces the protective effect.
How to Take — Two Different Routines
Immediate-release risedronate (Actonel and generic 5, 30, 35, 75, 150 mg tablets): Per the FDA prescribing information, take on first waking, before any food, drink, or other medication. Swallow the tablet whole with at least 6 to 8 oz of plain water — never coffee, tea, mineral water, juice, or milk. Do not chew or suck the tablet (oropharyngeal ulceration risk). Avoid lying down for at least 30 minutes after taking the medication, and do not eat, drink, or take any other oral medication for at least 30 minutes after the dose.
Delayed-release risedronate (Atelvia 35 mg once weekly): Take in the morning immediately after breakfast, while sitting or standing, with at least 4 oz of plain water. Avoid lying down for 30 minutes. Do not chew, cut, or crush the tablet — the coating is essential for the delayed-release formulation. Atelvia and Actonel must never be taken together.
If a weekly dose is missed, take it the morning the patient remembers and resume the original day the following week — never two doses on the same day. Specific make-up rules apply to the 75 mg twice-monthly and 150 mg once-monthly regimens; consult the medication guide.
Sources
- U.S. Food and Drug Administration / AbbVie. ACTONEL (risedronate sodium) tablets — full prescribing information. Revised 2026. Available via DailyMed: dailymed.nlm.nih.gov Primary source for FDA-approved indications, dosing, contraindications, drug interactions, and the adult adverse-reaction tables (Table 1 incidence figures) cited throughout this monograph.
- U.S. Food and Drug Administration / AbbVie. ATELVIA (risedronate sodium) delayed-release tablets — full prescribing information. Revised 2026. Available via DailyMed: dailymed.nlm.nih.gov Reference for the delayed-release formulation, including the post-breakfast administration regimen and the broader interaction profile (PPIs, H2 blockers, magnesium, iron).
- U.S. Food and Drug Administration. FDA Drug Safety Communication: Safety update for osteoporosis drugs, bisphosphonates, and atypical fractures. October 13, 2010. fda.gov Establishes the class-wide labelling for atypical femoral fractures and informs the duration-of-therapy reassessment recommendation; further updated in February 2026.
- Harris ST, Watts NB, Genant HK, et al. Effects of risedronate treatment on vertebral and nonvertebral fractures in women with postmenopausal osteoporosis: a randomized controlled trial. Vertebral Efficacy with Risedronate Therapy (VERT) Study Group. JAMA. 1999;282(14):1344–1352. doi.org/10.1001/jama.282.14.1344 VERT-North America — pivotal RCT demonstrating 41% reduction in new vertebral fractures and 39% reduction in nonvertebral fractures over 3 years with 5 mg/day.
- Reginster J, Minne HW, Sorensen OH, et al. Randomized trial of the effects of risedronate on vertebral fractures in women with established postmenopausal osteoporosis. Vertebral Efficacy with Risedronate Therapy (VERT) Study Group. Osteoporos Int. 2000;11(1):83–91. doi.org/10.1007/s001980050010 VERT-Multinational — companion RCT showing 49% reduction in new vertebral fractures over 3 years.
- McClung MR, Geusens P, Miller PD, et al. Effect of risedronate on the risk of hip fracture in elderly women. Hip Intervention Program (HIP) Study Group. N Engl J Med. 2001;344(5):333–340. doi.org/10.1056/NEJM200102013440503 Pivotal hip-fracture RCT supporting the nonvertebral fracture composite endpoint in postmenopausal osteoporosis.
- Reid DM, Hughes RA, Laan RF, et al. Efficacy and safety of daily risedronate in the treatment of corticosteroid-induced osteoporosis in men and women: a randomized trial. J Bone Miner Res. 2000;15(6):1006–1013. doi.org/10.1359/jbmr.2000.15.6.1006 Pivotal trial supporting the glucocorticoid-induced osteoporosis indication.
- Boonen S, Orwoll ES, Wenderoth D, Stoner KJ, Eusebio R, Delmas PD. Once-weekly risedronate in men with osteoporosis: results of a 2-year, placebo-controlled, double-blind, multicenter study. J Bone Miner Res. 2009;24(4):719–725. doi.org/10.1359/jbmr.081214 Pivotal RCT supporting the male osteoporosis indication for once-weekly 35 mg risedronate.
- Delmas PD, McClung MR, Zanchetta JR, et al. Efficacy and safety of risedronate 150 mg once a month in the treatment of postmenopausal osteoporosis. Bone. 2008;42(1):36–42. doi.org/10.1016/j.bone.2007.09.001 Pivotal trial supporting the 150 mg once-monthly dosing regimen.
- Camacho PM, Petak SM, Binkley N, et al. American Association of Clinical Endocrinologists / American College of Endocrinology clinical practice guidelines for the diagnosis and treatment of postmenopausal osteoporosis — 2020 update. Endocr Pract. 2020;26(Suppl 1):1–46. Executive summary: doi.org/10.4158/GL-2020-0524 Provides risk-stratified treatment selection for postmenopausal osteoporosis, including positioning of oral bisphosphonates as first-line therapy.
- Eastell R, Rosen CJ, Black DM, Cheung AM, Murad MH, Shoback D. Pharmacological management of osteoporosis in postmenopausal women: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2019;104(5):1595–1622. doi.org/10.1210/jc.2019-00221 Endocrine Society guidance on initial therapy choice and duration; positions risedronate alongside alendronate as first-line oral bisphosphonates.
- Buckley L, Guyatt G, Fink HA, et al. 2017 American College of Rheumatology guideline for the prevention and treatment of glucocorticoid-induced osteoporosis. Arthritis Rheumatol. 2017;69(8):1521–1537. doi.org/10.1002/art.40137 Source for the GIO risk-stratified therapy approach used alongside the FDA-labelled risedronate dosing.
- Adler RA, El-Hajj Fuleihan G, Bauer DC, et al. Managing osteoporosis in patients on long-term bisphosphonate treatment: report of a task force of the American Society for Bone and Mineral Research. J Bone Miner Res. 2016;31(1):16–35. doi.org/10.1002/jbmr.2708 ASBMR consensus on long-term therapy duration, drug holidays, and reassessment criteria for the bisphosphonate class.
- Ralston SH, Corral-Gudino L, Cooper C, et al. Diagnosis and management of Paget’s disease of bone in adults: a clinical guideline. J Bone Miner Res. 2019;34(4):579–604. doi.org/10.1002/jbmr.3657 Evidence-based clinical guideline developed using GRADE methodology by a Guideline Development Group led by the Paget’s Association (UK), covering diagnosis and pharmacological/non-pharmacological management of Paget’s disease.
- Russell RGG, Watts NB, Ebetino FH, Rogers MJ. Mechanisms of action of bisphosphonates: similarities and differences and their potential influence on clinical efficacy. Osteoporos Int. 2008;19(6):733–759. doi.org/10.1007/s00198-007-0540-8 Comprehensive review of nitrogen-containing bisphosphonate pharmacology; positions risedronate among the pyridinyl-ring bisphosphonates with intermediate skeletal affinity.
- Khan AA, Morrison A, Hanley DA, et al. Diagnosis and management of osteonecrosis of the jaw: a systematic review and international consensus. J Bone Miner Res. 2015;30(1):3–23. doi.org/10.1002/jbmr.2405 International consensus on ONJ definition, risk factors, and dental management for the bisphosphonate class.
- Mitchell DY, St Peter JV, Eusebio RA, et al. Effect of renal function on risedronate pharmacokinetics after a single oral dose. Br J Clin Pharmacol. 2000;49(3):215–222. doi.org/10.1046/j.1365-2125.2000.00135.x Source for the linear relationship between creatinine clearance and risedronate renal clearance, supporting the FDA cutoff at CrCl <30 mL/min.
- Mitchell DY, Eusebio RA, Sacco-Gibson NA, et al. Risedronate pharmacokinetics and intra- and inter-subject variability upon single-dose intravenous and oral administration. Pharm Res. 2001;18(2):166–170. doi.org/10.1023/A:1011024200280 Source for the absolute bioavailability of approximately 0.6%, the IV-route excretion data (65% in 24 hours, 85% over 28 days), and confirmation that tablet and oral solution formulations are bioequivalent.
- Roux C, Goldstein JL, Zhou X, Klemes A, Lindsay R. Vertebral fracture efficacy during risedronate therapy in patients using proton pump inhibitors. Osteoporos Int. 2012;23(1):277–284. doi.org/10.1007/s00198-011-1574-5 Pooled analysis from VERT-NA, VERT-MN, and HIP showing that immediate-release risedronate’s fracture-protective effect is preserved with PPI co-use.
- Watts NB, Chines A, Olszynski WP, et al. Fracture risk remains reduced one year after discontinuation of risedronate. Osteoporos Int. 2008;19(3):365–372. doi.org/10.1007/s00198-007-0460-7 Post-trial follow-up demonstrating persistent fracture-risk reduction at 1 year after discontinuation of risedronate, supporting the position that residual antifracture effect persists despite the relatively shorter terminal half-life.