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Fosamax

Generic name: alendronatea-LEN-dro-nate ]
Brand names: Binosto, Fosamax
Drug class: Bisphosphonates

Medically reviewed by Kaci Durbin, MD. Last updated on Aug 15, 2023.

What is Fosamax?

Fosamax is a bisphosphonate (bis FOS fo nayt) medicine that alters bone formation and breakdown in the body. This can slow bone loss and may help prevent bone fractures.

Fosamax is used in women to treat or prevent osteoporosis caused by menopause and in men and women to treat osteoporosis caused by taking steroids.

Fosamax is also used to increase bone mass in men who have osteoporosis, and to treat Paget's disease of bone in men and women.

Warnings

You should not take Fosamax if you have problems with your esophagus, or low levels of calcium in your blood.

Do not take Fosamax if you cannot sit upright or stand for at least 30 minutes after taking the medicine.

Fosamax can cause serious problems in the stomach or esophagus. Stop using this medicine and call your doctor at once if you have chest pain, new or worsening heartburn, or pain when swallowing.

In rare cases, this medicine may cause bone loss (osteonecrosis) in the jaw or a broken leg bone called a femur fracture. Symptoms of osteonecrosis include jaw pain or numbness, red or swollen gums, loose teeth, or slow healing after dental work. Symptoms of a femur fracture include leg or groin pain.

Also call your doctor if you have muscle spasms, numbness or tingling (in hands and feet or around the mouth), new or unusual hip pain, or severe pain in your joints, bones, or muscles.

Before taking this medicine

You should not take Fosamax if you are allergic to alendronate, or if you have:

Do not take Fosamax if you cannot sit upright or stand for at least 30 minutes. Fosamax can cause serious problems in the stomach or esophagus. You must stay upright for at least 30 minutes after taking this medicine.

To make sure this medicine is safe for you, tell your doctor if you have ever had:

In rare cases, this medicine may cause bone loss (osteonecrosis) in the jaw. Symptoms include jaw pain or numbness, red or swollen gums, loose teeth, or slow healing after dental work. The longer you use Fosamax, the more likely you are to develop this condition.

Osteonecrosis of the jaw may be more likely if you have cancer or received chemotherapy, radiation, or steroids. Other risk factors include blood clotting disorders, anemia (low red blood cells), and a pre-existing dental problem.

Fosamax has also been reported to cause fractures, or broken bones, in the large bones of the leg. Tell your doctor if you have any leg or groin pain while using Fosamax.

Talk with your doctor about the risks and benefits of using this medication.

It is not known whether Fosamax will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant. Stop using the medicine and tell your doctor right away if you become pregnant.

It is not known whether alendronate passes into breast milk or if it could harm a nursing baby. Ask your doctor about any risk.

How should I take Fosamax?

Take Fosamax exactly as prescribed by your doctor. Fosamax is taken either once daily or once per week. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take Fosamax first thing in the morning, at least 30 minutes before you eat or drink anything or take any other medicine. If you take this medicine only once per week, take it on the same day each week and always first thing in the morning.

Take with a full glass (6 to 8 ounces) of plain water. Do not use coffee, tea, soda, juice, or mineral water. Do not eat or drink anything other than plain water.

Do not crush, chew, or suck on an Fosamax tablet. Swallow the tablet whole.

For at least 30 minutes after taking Fosamax:

Pay special attention to your dental hygiene while taking Fosamax. Brush and floss your teeth regularly. If you need to have any dental work (especially surgery), tell the dentist ahead of time that you are using alendronate.

Fosamax is only part of a complete program of treatment that may also include diet changes, exercise, bone mineral density testing, and taking calcium and vitamin supplements. Follow your doctor's instructions very closely.

Store at room temperature away from moisture and heat.

Your doctor will determine how long to treat you with this medicine. Fosamax is often given for only 3 to 5 years.

What happens if I miss a dose?

Once-daily dosing: If you forget to take Fosamax first thing in the morning, do not take it later in the day. Wait until the following morning and skip the missed dose. Do not take two (2) doses in one day.

Once-per-week dosing: If you forget to take Fosamax on your scheduled day, take it first thing in the morning on the day after you remember the missed dose. Then return to your regular weekly schedule on your chosen dose day. Do not take 2 doses in one day.

What happens if I overdose?

Drink a full glass of milk and seek emergency medical attention or call the Poison Help line at 1-800-222-1222. Do not make yourself vomit and do not lie down.

What to avoid

Avoid taking any other medicines for at least 30 minutes after taking Fosamax. This includes vitamins, calcium, and antacids. Some medicines can make it harder for your body to absorb alendronate.

Avoid smoking, or try to quit. Smoking can reduce your bone mineral density, making fractures more likely.

Avoid drinking large amounts of alcohol. Heavy drinking can also cause bone loss.

Fosamax side effects

Get emergency medical help if you have signs of an allergic reaction to Fosamax: hives; wheezing, difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using Fosamax and call your doctor at once if you have:

Common Fosamax side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Fosamax?

Tell your doctor about all your current medicines and any you start or stop using, especially:

This list is not complete. Other drugs may interact with alendronate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide. Talk with your doctor about the best dosing schedule for your other medicines.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Fosamax only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.