Alendon

Approved Indications:

• Postmenopausal Osteoporosis in women: To increase bone mass and reduce risk of vertebral and hip fractures.
• Male Osteoporosis: Increases bone mass and reduces fracture risk in male patients with primary or hypogonadal osteoporosis.
• Glucocorticoid‑Induced Osteoporosis: For patients receiving oral systemic glucocorticoids (equivalent to ≥7.5 mg prednisone daily for ≥3 months), to prevent bone loss in both sexes.

Clinically Accepted Off‑Label Uses:

• Paget’s Disease of Bone: Used off‑label to suppress increased bone turnover.
• Osteopenia (Select High‑Risk Patients): For patients with osteopenia and high fracture risk (e.g., FRAX score).
• Bone Loss in Secondary Conditions: Such as systemic lupus erythematosus or rheumatoid arthritis long‑term steroid use.

Adults (including elderly):

• Osteoporosis (women and men): 70 mg orally once weekly or 10 mg daily.
• Glucocorticoid‑Induced Osteoporosis: 5 mg daily or 35 mg once weekly in men or premenopausal women. Postmenopausal women: usually 5 mg daily (unless high fracture risk).
• Paget’s Disease (off‑label): 40 mg daily for 6 months (alternative regimen: 30 mg daily for 2 months followed by titration).

Pediatrics (<18 years): Not recommended; safety and efficacy not established except under specialized supervision for Paget’s disease.

Administration Instructions:

• Take first thing in the morning after waking with a full glass (≥6–8 oz) of plain water.
• Swallow whole; do not chew or suck tablet.
• Remain upright (sitting, standing, or walking) for at least 30 minutes after dosing and until after first food, beverage, or medication of the day.
• Do not eat, drink other beverages (except plain water), or take other medications for at least 30 minutes.

Special Populations:

• Renal Impairment: Use with caution if creatinine clearance <35 mL/min; not recommended below this threshold.
• No hepatic dose adjustment needed.

Alendronic acid is a nitrogen‑containing bisphosphonate that selectively binds to hydroxyapatite in bone, particularly at sites of active bone resorption. Osteoclasts internalize alendronate during resorption, which inhibits farnesyl pyrophosphate synthase in the mevalonate pathway, leading to osteoclast apoptosis and decreased bone turnover. This suppression of osteoclastic activity results in reduced bone loss, increased bone mineral density (BMD), and decreased risk of fractures.

• Absorption: Oral bioavailability is poor (~0.6% fasting conditions).
• Absorption Reduced By: Food, beverages other than water, calcium or other minerals.
• Distribution: Rapid uptake into bone; plasma half‑life ~1 hour; terminal skeletal retention for years.
• Metabolism: Not metabolized.
• Elimination: Not metabolized; unabsorbed drug excreted unchanged in urine; absorbed portion excreted by kidney (~50%) and incorporated into bone.
• Onset of Therapeutic Effect: Increase in BMD after ~3–6 months; fracture risk reduction observed after ~12 months.

• Pregnancy:
• No formal FDA pregnancy category (PLLR guidelines). Animal studies show skeletal changes in offspring at high doses; human data limited. Use only if clearly needed.
• Lactation:
• Alendronate is excreted in animal milk; no data in human milk. Use caution; avoid during breastfeeding when possible.

• Primary Class: Bisphosphonate
• Subclass: Nitrogen‑containing bisphosphonate (second-generation)
• Pharmacologic: Anti‑resorptive agent for bone

• Known hypersensitivity to alendronate or excipients
• Hypocalcemia (must be corrected prior to therapy)
• Esophageal abnormalities delaying emptying (e.g., stricture or achalasia)
• Inability to remain upright for ≥30 minutes
• Severe renal impairment (creatinine clearance <35 mL/min)

• Esophageal Irritation: Risk of esophagitis, ulcers, or bleeding. Advise proper administration and upright posture.
• Hypocalcemia: Correct prior to initiation; monitor calcium, vitamin D levels.
• Atypical Femoral Fractures: Rare risk with long-term use (>3–5 years); evaluate thigh/groin pain.
• Osteonecrosis of the Jaw (ONJ): Rare, especially in dental extractions or invasive dental procedures. Dental exam recommended before prolonged therapy.
• Musculoskeletal Pain: Severe, sometimes disabling bone/muscle/joint pain reported.
• Renal Function: Monitor; avoid in severe impairment.
• Vitamin D and Calcium Supplementation: Ensure adequacy during therapy.

Common:

• Gastrointestinal system: dyspepsia, abdominal pain, nausea, constipation, diarrhea.
• Musculoskeletal pain: back pain, arthralgia.

Less Common:

• Esophagitis, gastritis, esophageal ulcers (with improper administration)
• Headache, dizziness
• Rash

Rare/Serious:

• Atypical femoral fractures
• Osteonecrosis of the jaw
• Severe and prolonged musculoskeletal pain
• Esophageal perforation
• Hypersensitivity reactions (rare)

Onset & Dose‑Dependence:

• GI symptoms often occur soon after initial doses.
• Serious adverse events usually associated with long-term therapy (≥years) or misuse.

• Calcium, Magnesium, Iron Supplements, Antacids: Reduce absorption if taken within 30 minutes.
• NSAIDs: May increase risk of GI irritation.
• Aspirin or Other NSAIDs: Combined use may increase dyspepsia or GI bleeding.
• Food: Dairy or mineral-rich foods significantly reduce bioavailability.
• No CYP450 Interactions: Alendronic acid is not metabolized by CYP system.

• Drug Holiday Recommendations: Emerging guidance suggests drug “holiday” after 5 years of oral therapy in low-to-moderate risk patients.
• Guideline Preference: Updated osteoporosis guidelines position alendronate as first-line due to cost‑effectiveness and fracture prevention profile.
• Safety Alerts: Regulatory agencies have highlighted monitoring for atypical fractures and ONJ; advisories emphasize dental assessment.

• Temperature: Store at 20 °C to 25 °C (68–77 °F); excursions permitted between 15 °C and 30 °C.
• Light & Humidity: Keep in a dry place and protect from excessive light.
• Handling:
• Blister-packed tablets should remain sealed until use.
• Do not use if foil blister is damaged.
• Reconstitution: Not applicable—solid oral tablets only.