Alendronate
Alendronate is a bisphosphonate medication used to treat and prevent osteoporosis by reducing bone loss. It works by inhibiting the cells that break down bone (osteoclasts), helping to maintain or increase bone density and reduce fracture risk. This medication is commonly prescribed for postmenopausal women, men with osteoporosis, and patients on long-term corticosteroid therapy.
Alendronate is a bone-strengthening medication that treats osteoporosis by preventing the breakdown of bone tissue.
Key facts at a glance
- ATC
- M05BA04
- Generic
- Alendronate
- Class
- bisphosphonate
- Brands
- Fosamax
- Availability
- rx
- Pregnancy
- C
- Lactation
- caution
- Half-life (h)
- 6000
- Routes
- oral
- Forms
- tablet
- Regions
- CN, US, EU, JP
- Monitoring
- esophageal-irritation, calcium
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 70mg once weekly
- Maximum
- consult physician
- Frequency
- once weekly
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- not indicated
- Maximum
- consult physician
- Frequency
- not applicable
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 70mg once weekly
- Maximum
- consult physician
- Frequency
- once weekly
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
10 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks to the fetus
regular fetal monitoring and ultrasound assessments
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second trimesteravoid if possible
discontinue therapy if pregnancy occurs; consider alternative treatments
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
third trimesteravoid if possible
do not use near delivery; may affect fetal bone development
fetal growth monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
not applicableavoid or discontinue breastfeeding
not recommended during breastfeeding; decide whether to discontinue drug or breastfeeding
monitor infant for any adverse effects
geriatric
over 65 yearsno dosage adjustment required
use standard dosing; monitor renal function periodically
regular renal function monitoring, assess for gastrointestinal adverse effects
pediatric_age
under 18 yearsnot recommended; do not use
safety and efficacy not established in pediatric population
not applicable
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
severe creatinine clearance below 35contraindicated
do not use in patients with severe renal impairment
monitor renal function before and during treatment
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
mild moderate creatinine clearance 35 80no dose adjustment needed
use with caution; ensure adequate hydration
monitor renal function periodically
Use with caution and monitor for adverse effects.
hepatic_impairment
mild moderateno dosage adjustment required
no dose adjustment needed for mild to moderate impairment
standard monitoring
alcohol_users
chronic heavy useuse with caution
limit alcohol consumption; may increase risk of gastrointestinal adverse effects
monitor for gastrointestinal complications
Use with caution and monitor for adverse effects.
Statistics and clinical data
FDA approval year
Original FDA approval for Alendronate (Fosamax)
Drug class
Pharmacological classification of Alendronate
Primary indications
Main therapeutic uses of Alendronate
Mechanism of action
Primary pharmacological mechanism
Treatment and prevention of osteoporosis in postmenopausal women, treatment of osteoporosis in men, treatment of glucocorticoid-induced osteoporosis, and treatment of Paget's disease of bone.
Alendronate binds to bone mineral and is taken up by osteoclasts (bone-resorbing cells), where it inhibits their activity and promotes apoptosis, thereby reducing bone breakdown and helping to maintain bone density.
Must be taken first thing in the morning with plain water on an empty stomach; remain upright for at least 30-60 minutes after taking to prevent esophageal irritation. Common side effects include gastrointestinal symptoms. Rare but serious risks include osteonecrosis of the jaw and atypical femur fractures with long-term use. Calcium and vitamin D supplementation is often recommended alongside treatment.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 22, 2026. · Read our editorial policy