Alendronate Uses, Dosage, Side Effects, Food Interaction and all others data.

Alendronate inhibits osteoclast-mediated bone-resorption. Like all bisphosphonates, it is chemically related to inorganic pyrophosphate, the endogenous regulator of bone turnover. But while pyrophosphate inhibits both osteoclastic bone resorption and the mineralization of the bone newly formed by osteoblasts, alendronate specifically inhibits bone resorption without any effect on mineralization at pharmacologically achievable doses. Its inhibition of bone-resorption is dose-dependent and approximately 1,000 times stronger than the equimolar effect of the first bisphosphonate drug, etidronate. Under therapy, normal bone tissue develops, and alendronate is deposited in the bone-matrix in a pharmacologically inactive form. For optimal action, enough calcium and vitamin D are needed in the body in order to promote normal bone development. Hypocalcemia should, therefore, be corrected before starting therapy.

Alendronate tablets have a very low oral bioavialability. After administration it distributes into soft tissue and bone or is excreted in the urine. Alendronate does not undergo metabolism.

Trade Name Alendronate
Generic Alendronic acid
Alendronic acid Other Names ABDP, Acide Alendronique, Acido Alendronico, Acidum Alendronicum, Alendronate, Alendronic acid
Weight 70mg/75ml, 10mg, 35mg, 40mg, 5mg, 70mg,
Type Oral Solution, Oral Tablet, Effervescent
Formula C4H13NO7P2
Weight Average: 249.096
Monoisotopic: 249.016724799
Protein binding

78%. Studies in rats show that plasma protein binding increases with decreasing alendronic acid plasma concentration and increasing pH.

Groups Approved
Therapeutic Class Bisphosphonate preparations
Available Country United States
Last Updated: September 19, 2023 at 7:00 am


Alendronate is used for the-

  • Treatment and prevention of osteoporosis in post-menopausal women
  • Treatment of osteoporosis, Alendronate increases bone mass and reduces the incidence of fractures, including those of the hip and spine (vertebral compression fractures)
  • Prevention of osteoporosis, Alendronate may be considered in postmenopausal women who are at risk of developing osteoporosis and for whom the desired clinical outcome is to maintain bone mass and to reduce the risk of future fracture
  • Treatment toincrease bone mass in men with osteoporosis
  • Treatment of glucocorticoid-induced osteoporosis in men and women receiving glucocorticoids in a daily dosage equivalent to 7.5 mg or greater of prednisone and who have low bone mineral density. Patients treated with glucocorticoids should receive adequate amounts of calcium and vitamin D
  • Treatment of Paget’s disease of bone in men and women

Alendronate is also used to associated treatment for these conditions: Osteogenesis Imperfecta (OI), Osteoporosis, Osteoporosis caused by glucocorticoid, Paget’s Disease

How Alendronate works

Alendronate binds to bone hydroxyapatite. Bone resorption causes local acidification, releasing alendronic acid which is that taken into osteoclasts by fluid-phase endocytosis. Endocytic vesicles are acidified, releasing alendronic acid to the cytosol of osteoclasts where they induce apoptosis. Inhibition of osteoclasts results in decreased bone resorption which is shown through decreased urinary calcium, deoxypyridinoline and cross-linked N-telopeptidases of type I collagen.


Alendronate dosage

Treatment of osteoporosis in post-menopausal women: The recommended dose is one Alendronate 70 mg once weekly or 10 mg once daily.

Treatment to increase bone mass in men with osteoporosis:The recommended dose is one Alendronate tablet 10 mg once daily. Alternatively, one Alendronate 70 mg once weekly may be considered.

Prevention of osteoporosis in post-menopausal women: The recommended dose is 35 mg once weekly or 5 mg once daily. The safety of treatment and prevention of osteoporosis with Alendronate has been studied for up to 7 years.

Use for elderly patients: No dosage adjustment is required for elderly patients. Because in clinical study there was no evidence of age related differences in the efficacy or safety profiles of Alendronate.

Treatment of glucocorticoid-induced osteoporosis in men and women: The recommended dose is 5 mg once daily, except for post-menopausal women not receiving oestrogen, for whom the recommended dose is 10 mg once daily.

Paget’s disease of bone in men and women: The recommended treatment regimen is 40 mg once a day for six months.

Side Effects

The commonest symptomatic side effects are constipation, diarrhoea, oesophageal ulcer, flatulence, dysphagia, musculoskeletal pain, headache, rarely rash, erythema, transient decrease in serum calcium and phosphate, nausea, vomiting, peptic ulceration, hypersensitivity reactions including urticaria and angio-oedema.


In clinical studies, ≥3% of patients experience abdominal pain, acid regurgitation, constipation, diarrhea, dyspepsia, musculoskeletal pain, and nausea.

No information for treatment of overdose is available, however patients should be given milk or antacids to bind alendronic acid and vomiting should not be induced. Patients may experience hypocalcemia, hypophosphatemia, and upper gastrointestinal events..

There are currently no studies for safety and efficacy in pregnancy, though studies in pregnant rats show fetal and maternal complications at 4 times the clinical dose and pregnant rabbits do not show complications at as high as 10 times the clincal dose.

Excretion in breast milk, and therefore safety in lactation, is unknown.

Alendronate has been studied for use in pediatric patients. The oral bioavailability is similar to that in adult patients, but an increase in the portion of patients experiencing vomiting.

There is no significant difference in efficacy or safety of alendronic acid in geriatric populations, though there is potential for even greater sensitivity in patients at a further advanced age than those in the study.

Alendronate is not recommended for patients with creatinine clearance Label.


The incidence of upper gastrointestinal side effects are increased with the concomitant use of non-steroidal anti-inflammatory agents and aspirin. Absorption of Alendronate is reduced in the presence of antacids and calcium supplements.

Food Interaction

  • Administer vitamin supplements. Patients may require supplemental vitamin D.
  • Avoid multivalent ions. Calcium, antacids, and divalent ions may interfere with the absorption of this medication.
  • Take before a meal. Take 30-60 minutes before breakfast.
  • Take with a full glass of water.

Volume of Distribution


Elimination Route

Mean oral bioavailability of alendronic acid in women is 0.64% and in men is 0.59%. Bioavailability of alendronic acid decreases by up to 40% if it is taken within an hour of a meal.

Half Life

Due to alendronic acid being incorporated into the skeleton, the terminal half life is estimated to be over 10 years.



Elimination Route

Administration of radiolabeled alendronic acid results in 50% recovery in urine within 72 hours. No alendronic acid is recovered in the feces. Men excrete less alendronic acid than women, though race and advanced age do not affect elimination.

Pregnancy & Breastfeeding use

Alendronate should not be given to pregnant women or nursing mother.


Hypocalcaemia; Renal impairment; Vitamin D deficiency; Active gastrointestinal problem such as dysphagia, oesophago-duodenitis or ulcer; and Hypersensitivity to any components of the tablet.

Special Warning

Children: Not recommended.

Innovators Monograph

You find simplified version here Alendronate

Alendronate contains Alendronic acid see full prescribing information from innovator Alendronate Monograph, Alendronate MSDS, Alendronate FDA label


What is Alendronate used for?

Alendronate is a bisphosphonate medication used to treat osteoporosis and Paget's disease of bone. Taking Alendronate can help if you have, or are at risk of developing, osteoporosis. This is a condition that causes your bones to get weaker and be more likely to break.

How safe is Alendronate?

This evidence shows Alendronate to be safe and effective; it should be considered the nonhormonal therapy of choice for treating osteoporosis in postmenopausal women at risk for hip and vertebral fractures.

How does Alendronate work?

Alendronate works by slowing down the production of the cells that wear down bone (osteoclasts). This helps to improve bone strength and makes the bone less fragile.

What are the common side effects of Alendronate?

Some people may have serious side effects when taking Alendronate. These include heartburn (or heartburn that gets worse), problems or pain when swallowing, or chest pain. These may be signs of ulcers in your food pipe (oesophagus). If this happens, stop taking Alendronate and speak to a doctor.

Is Alendronate safe during pregnancy?

Alendronate should not be used during pregnancy.

Is Alendronate safe during breastfeeding?

It is not known whether Alendronate is excreted into human breast milk. Given the indication, Alendronate tablet should not be used by breast-feeding women.

Can I drink alcohol with Alendronate?

Yes, you can drink alcohol while taking Alendronate. However, drinking a lot of alcohol affects the strength of your bones and can increase your risk of breaks (fractures).

Can I drive after taking Alendronate?

Alendronate may make you feel dizzy. It can also cause blurred vision, and bone, muscle or joint pain. If this happens to you, do not drive, cycle or use any machinery or tools until the effects have worn off.

When should be taken of Alendronate?

Take Alendronate first thing in the morning, before you have anything to eat or drink and before you take any other medicines. Stay sitting or standing for 30 minutes so the medicine does not irritate your food pipe (oesophagus).

How many time can I take Alendronate daily?

The usual dose of Alendronate for adults is 70mg taken once a week. There is also a 10mg tablet you take once a day. You will usually take Alendronate once a week: as a standard tablet.

How often should Alendronate be taken?

Alendronate is taken either once daily or once per week. Follow your doctor's dosing instructions very carefully.

How long does Alendronate take to work?

Alendronate usually starts to work after 1 month.

How long does Alendronate stay in my system?

You'll usually take Alendronate long term, for at least 3 to 5 years. The longer you take the medicine, the longer the effects will last.

Who should not take Alendronate?

Alendronate should not be given to children and adolescents. You may suffer from a stomach upset, heartburn, inflammation of the gullet or stomach, muscle and stomach cramps, spasms, weakness and fits.

What happen If I stop taking Alendronate?

Once you stop taking Alendronate, the effects of the medicine will gradually wear off. Your bones may continue to benefit for up to 5 years afterwards. The longer you take the medicine, the longer the effects will last.

What happen If I missed Alendronate?

Patients should be instructed that if they miss a dose of Alendronate once weekly tablet, they should take one tablet on the morning after they remember. They should not take two tablets on the same day but should return to taking one tablet once a week, as originally scheduled on their chosen day.

What happen if I overdose on Alendronate?

Hypocalcaemia, hypophosphataemia and upper gastro-intestinal adverse events, such as upset stomach, heartburn, oesophagitis, gastritis, or ulcer, may result from oral overdosage. No specific information is available on the treatment of overdosage with Alendronate.

Will Alendronate affect my fertility?

There's no evidence to suggest that taking Alendronate will reduce fertility in either men or women.

Can Alendronate affect my kidneys?

Alendronate was found to be safe and effective for the treatment of osteoporosis in women with decreased renal function.

Can Alendronate affects my liver?

Alendronate treatment has also been considered as a potential hepatotoxic agent, as high serum liver enzyme concentrations and hepatitis have occasionally been reported in a few patients while receiving Alendronate.
*** Taking medicines without doctor's advice can cause long-term problems.