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Alendronate is used to prevent and treat certain types of bone loss (osteoporosis) in adults. Osteoporosis causes bones to become thinner and break more easily. Your chance of developing osteoporosis increases as you age, after menopause, or if you are taking corticosteroid medications (such as prednisone) for a long time.

This medication works by slowing bone loss. This effect helps maintain strong bones and reduce the risk of broken bones (fractures). Alendronate belongs to a class of drugs called bisphosphonates.

How to use Fosamax

Read the Medication Guide provided by your pharmacist before you start taking alendronate and each time you get a refill. Follow the instructions very closely to make sure your body absorbs as much drug as possible and to reduce the risk of injury to your esophagus. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth once a day, after getting up for the day and before taking your first food, beverage, or other medication. Take it with a full glass (6-8 ounces or 180-240 milliliters) of plain water. Swallow the tablet whole. Do not chew or suck on it. Then stay fully upright (sitting, standing, or walking) for at least 30 minutes and do not lie down until after your first food of the day. Alendronate works only if taken on an empty stomach. Wait at least 30 minutes (preferably 1 to 2 hours) after taking the medication before you eat or drink anything other than plain water.

Do not take this medication at bedtime or before rising for the day. It may not be absorbed and you may have side effects.

Calcium or iron supplements, vitamins, antacids, coffee, tea, soda, mineral water, calcium-enriched juices, and food can decrease the absorption of alendronate. Do not take these for at least 30 minutes (preferably 1 to 2 hours) after taking alendronate.

Take this medication regularly to get the most benefit from it. Remember to use it at the same time each morning. Talk to your doctor about the risks and benefits of long-term use of this medication.

Side Effects

Stomach pain, constipation, diarrhea, gas, or nausea may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: jaw pain, increased or severe bone/joint/muscle pain, new or unusual hip/thigh/groin pain, swelling of joints/hands/ankles/feet, black/tarry stools, vomit that looks like coffee grounds.

This medication may infrequently cause serious irritation and ulcers of the esophagus. If you notice any of the following unlikely but very serious side effects, stop taking alendronate and talk to your doctor or pharmacist right away: new or worsening heartburn, chest pain, pain or difficulty when swallowing.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.


Before taking alendronate, tell your doctor or pharmacist if you are allergic to it; or to other bisphosphonates; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: disorders of the esophagus (such as esophageal stricture or achalasia), trouble swallowing, trouble standing or sitting upright for at least 30 minutes, low calcium levels, kidney problems, stomach/intestinal disorders (such as ulcers).

Some people taking alendronate may have serious jawbone problems. Your doctor should check your mouth before you start this medication. Tell your dentist that you are taking this medication before you have any dental work done. To help prevent jawbone problems, have regular dental exams and learn how to keep your teeth and gums healthy. If you have jaw pain, tell your doctor and dentist right away.

Before having any surgery (especially dental procedures), tell your doctor and dentist about this medication and all other products you use (including prescription drugs, nonprescription drugs, and herbal products). Your doctor or dentist may tell you to stop taking alendronate before your surgery. Follow all instructions about stopping or starting this medication.

This drug is not recommended for use in children. Studies have shown that many children who took this drug had severe side effects such as vomiting, fever, and flu-like symptoms.

Caution is advised if you are pregnant or planning to become pregnant in the future. Alendronate may stay in your body for many years. Its effects on an unborn baby are unknown. Discuss the risks and benefits with your doctor before starting treatment with alendronate.

It is unknown if this medication passes into breast milk. Consult your doctor before breast-feeding.


See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.


If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe stomach pain, painful heartburn, pain in the esophagus (chest pain), muscle weakness/cramps, mental/mood changes.


Do not share this medication with others.

Lifestyle changes that help promote healthy bones include increasing weight-bearing exercise, stopping smoking, limiting alcohol, and eating well-balanced meals that contain adequate calcium and vitamin D. You may also need to take calcium and vitamin D supplements. Consult your doctor for specific advice.

Laboratory and/or medical tests (X-rays, height measurement, blood mineral levels) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Missed Dose

If you miss a dose, skip the missed dose. Resume your usual dosing schedule the following day. Do not double the dose to catch up.


Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Information last revised March 2015. Copyright(c) 2015 First Databank, Inc.


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Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, expect as may be authorized by the applicable terms of use.

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

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