Doctors prescribe Fosamax (alendronate) to treat osteoporosis. The drug works by slowing down the body’s process of breaking down bone. Merck’s marketing of the drug and its safety have faced scrutiny by critics and the FDA. A February 2018 records check showed that the last time the FDA released new side effects warnings for Fosamax was in 2015.

Fosamax Pills
Fosamax Facts
  1. Dosage 5 mg, 10 mg, 35 mg, or 70 mg
  2. Used to Treat Osteoporosis
  3. Related Drugs Boniva, Actonel, Aredia, Didronel, Reclast Skelid, Zometa
  4. FDA Safety Communications Potential risk for esophageal cancer, risk of thigh bone (femur) fractures, risk of atrial fibrillation
  5. Active Ingredient Alendronate sodium and cholecalciferol
  6. FDA Approval 1995, also available as Fosamax Plus D approved in 2005

Fosamax (alendronate sodium) belongs to a drug class called bisphosphonates. Doctors prescribe these drugs for osteoporosis. Merck makes Fosamax.

About 10 million Americans have osteoporosis and about 44 million have low-bone density, putting them at risk of fractures. Osteoporosis is more common in women, but men may also suffer from the condition.

Biphosphonates work by slowing the body’s natural process of breaking down bone. This helps maintain or increase bone density.

The U.S. Food and Drug Administration approved Fosamax in 1995. It was the first drug in its class.

In 2005, the FDA approved Fosamax Plus D (alendronate sodium and cholecalciferol). This formula combines the original active ingredient in Fosamax plus vitamin D.

Fosamax brought in billions in annual revenue for Merck. In 2008, Merck lost its patent. Then, the FDA approved the first generic version of Fosamax.

The most common Fosamax side effects are irritation of the esophagus and stomach ulcers.

Bone With and Without Osteoporosis
Normal bone vs. bone with osteoporosis

But, studies link the drug to some serious but rare side effects. These include thigh fractures and jawbone problems. People who say they suffered these side effects filed lawsuits against Fosamax.

Some studies also link the drug to a small risk of esophageal cancer, though the FDA has not issued a warning.

The FDA changed the drug’s warning label in 2015. The 2015 warning was for the risk of jaw problems (osteonecrosis). These problems may increase with cancer drugs called angiogenesis inhibitors.

As of Feb. 21, 2018, the FDA had not released any new warnings.

Merck also faced scrutiny for its controversial marketing practices of the drug. These practices include using misleading ads and publishing fake journal articles.

How Does Fosamax Work?

As people get older, the body naturally breaks down more bone. This causes bones to become weaker and thinner. This process is called resorption. Fosamax treats bone loss by slowing the resorption process.

In clinical studies on animals, alendronate — Fosamax’s active ingredient — adhered to bones in rats and mice. Alendronate prevented resorption and new bone formed on top of the drug molecules, improving bone thickness. In order to keep slowing resorption and forming new bone, patients have to keep taking Fosamax.

Fast Fact
Fosamax’s active ingredient — alendronate — slows the resorption process while new bone is formed on top of the drug molecules, improving bone thickness.

Researchers looked at biomarkers of bone resorption in urine of post-menopausal women taking 10 mg of Fosamax a day. By tracking these markers, researchers were able to gauge how effective the drug was. Study results showed a 50 to 70 percent reduction in resorption. These resorption levels were similar to those found in premenopausal women.

Even if patients won’t see or feel a difference, Fosamax and Fosamax D have been shown to improve bone density in as little as one month. The improvement plateaued at three to six months after starting treatment, according to the medication insert.

Studies show that Fosamax is effective at reducing the risk of spine, hip and wrist fractures in women with osteoporosis. According to an article published online in Harvard Health Publications, the drug can improve bone density for at least 10 years.

Adverse Effects of Fosamax

According to the medication insert, Fosamax has been studied for safety in about 8,000 postmenopausal women. Researchers documented side effects from clinical trials. After the drug hit the market, researchers also received reports of additional side effects. The most common side effects were gastrointestinal issues and esophageal irritation.

Side effects in clinical trials and post-marketing experience include:
  • Abdominal pain
  • Nausea
  • Constipation
  • Diarrhea
  • Flatulence
  • Acid regurgitation
  • Bone, muscle or joint pain
  • Headache
  • Dizziness and vertigo
  • Fatigue
  • Esophageal ulcer
Rare side effects include:
  • Allergic reactions
  • Skin rashes including Stevens-Johnson syndrome (blisters and peeling skin)
  • Hypercalcemia (too much calcium in the blood)
  • Peripheral edema (swelling)
  • Gastric or duodenal ulcers
  • Femur fractures
  • Dead Jaw Syndrome, also known as osteonecrosis (a condition characterized by swelling, infection and bone death in the jaw)
  • Esophageal erosion with bleeding
  • Esophageal perforation
  • Hypocalcemia (low blood calcium)

FDA Actions and Fosamax Safety Issues

The FDA released a number of safety communications for Fosamax and other drugs in the same class. Key studies also added to growing safety concerns.

  • 2004
    The FDA found that long-term Fosamax use was linked to osteonecrosis of the jaw, which causes the jawbone to deteriorate.
  • 2007
    The FDA announced that it was aware of data linking Fosamax and other drugs in the class to potential increased risk of atrial fibrillation.
  • 2007
    The American Society for Bone and Mineral Research connected Fosamax to osteonecrosis of the jaw.
  • 2008
    The FDA warned that bisphosphonates were linked to debilitating bone, muscle and joint pain.
  • 2009
    A study in the New England Journal of Medicine linked long-term Fosamax use to esophageal cancer.
  • 2009
    A Swedish study found risk of femur stress fracture was 50 times higher in women who took Fosamax or another bisphosphonate compared to women who did not take the drugs.
  • 2010
    The FDA required that Fosamax and other drugs in its class include warning labels about the increase risk of thighbone (femur) fractures.
  • 2011
    The FDA added a new warning label to the drug that states that the optimal duration of Fosamax use has not been determined. An FDA advisory committee wants the agency to limit the amount of time a patient uses the drug, but the group can’t agree on the time limit.
  • 2013
    The FDA required a new warning for reports of “acute asthma exacerbations” with Fosamax.
  • 2015
    Merck updated the medication label to warn that risk for osteonecrosis of the jaw may increase with cancer treatments called angiogenesis inhibitors.
  • 2017
    A study in the New England Journal of Medicine showed risk of vertebral fracture with a new drug called romosozumab was 48 percent lower than with Fosamax. Arm and leg fracture risk was 27 percent lower.

Dosages and Strengths

Fosamax, which comes in a pill and liquid form, can be taken once a week or once daily, depending on the treatment. Fosamax Plus D only comes in a weekly tablet form. Doctors will determine the individual dosage for each patient.

Fosamax dosage strengths:
5 mg, 10 mg, 35 mg, 40 mg and 70 mg
Fosamax Plus D dosage strengths:
70 mg/2800 and 70 mg/5600

Instructions for Taking Fosamax and Fosamax Plus D

There is a narrow set of parameters for taking Fosamax. These instructions are very important. Not taking Fosamax as directed could decrease the medicine’s effectiveness or increase adverse events.

Because Fosamax is most effective when taken on an empty stomach, the drug should be taken at least a half hour before eating breakfast with a full glass of water. Patients should not lie down for at least 30 minutes after taking the pill. They should not eat, drink or take any other medications within 30 minutes of taking it. Patients should not take Fosamax at bedtime or before getting up for the day.

Fosamax 10mg Pill
Fosamax (10mg) should be taken once daily
Fosamax 70mg Pills
Fosamax Plus D (70mg) should be taken once a week

According to the medication insert, the recommended starting dosages are one 10 mg tablet once daily or a 70 mg tablet or oral solution once weekly.

The recommended starting dose of Fosamax D is 70 mg alendronate/5600 international units vitamin D3 once weekly.

Who Should Not Take Fosamax or Fosamax Plus D?

Because of how Fosamax works and is metabolized by the body, there are certain people who should not take the drug. The drug is known to cause irritation to the gastrointestinal lining and may worsen underlying diseases, including Barrett’s esophagus, dysphagia and gastritis. Doctors should be cautious when prescribing Fosamax to patients with preexisting conditions. Fosamax and Fosamax Plus D are not approved for use in children.

People with the following condition should not use Fosamax:
  • People with abnormalities or problems related to the esophagus
  • People who cannot sit upright or stand for at least 30 minutes
  • People with hypocalcemia (low calcium in the blood)
  • People allergic to ingredients in Fosamax or Fosamax Plus D
  • People at increased risk of aspiration, a condition where food or liquid is breathed into the airways, should not take liquid Fosamax.

Fosamax Drug Interactions

Fosamax is known to interact with several common medications. Some make the drug less effective, while others can increase the risk of side effects.

Drugs that can negatively alter the effectiveness of Fosamax include:
  • Aspirin and NSAIDs drugs (ibuprofen, naproxen and anaprox) cause increased stomach irritation
  • Iron supplements and magnesium products prevent Fosamax absorption
  • Antacids make Fosamax less effective

Fosamax Marketing Controversy

In July 1997, the FDA sent Merck a warning for falsely advertising Fosamax’s benefits in a brochure targeting postmenopausal women. The agency said Merck overstated the benefits of the drug and minimized the risks. The FDA called the content of the ad “misleading and in violation of the Federal Food, Drug and Cosmetic Act.”

The ad stated, “Menopause is the single most important cause of osteoporosis.” According to the FDA, this statement is false and implies that all women with menopause develop osteoporosis. The agency previously warned Merck of the same issues in December 1995 and April 1997, the letter states. The FDA requested Merck immediately discontinue the use of the brochure and similar materials.

Creating a Market for Fosamax

In order to reach the millions at risk for osteoporosis, Merck opened its nonprofit Bone Research Institute to encourage physicians to do bone exams. With it, the company was not only able to reach the osteoporosis market, but also convinced medical professionals that osteopenia — lower bone density not severe enough to be considered osteoporosis — needed treatment as well. Before Fosamax, osteopenia was rarely diagnosed or treated because it doesn’t cause disabling bone breaks.

Critics say that Merck created a disease simply to sell more Fosamax.

It started in 1995, when the company hired Jeremy Allen, formerly of a massive pharmaceutical research company called IMS Health, to help them sell Fosamax. The drug giant hired Allen after its initial sales were poor, he told National Public Radio in 2009.

Bone Scan on a Computer
Merck boosted sales of Fosamax by motivating large numbers of women to have their bones scanned for osteoporosis

Allen’s solution was to get large numbers of women to get their bones scanned and be diagnosed with osteoporosis. The company then approached companies to fund the development of smaller, cheaper bone scanners that experts said should not be used to diagnose osteoporosis.

After the machines were ready, Merck funded trials to get the machines past the FDA. Then, it sent out its sales team with information on the devices to doctors and created leasing programs to help doctors buy them. The pharma giant then lobbied for legislation called the Bone Mass Measurement Act to get Medicare to pay for the scans.

Fosamax sales soared into the billions within the next few years as a result of the bone scanners.

Fake Medical Journal to Sell Fosamax

In 2009, The Scientist magazine reported that Merck paid publisher Elsevier to produce the Australasian Journal of Bone and Joint Medicine, which looked like a peer-reviewed medical journal. In reality, it was a marketing tool for Fosamax and other Merck products, including its then blockbuster pain reliever, Vioxx. The journals were published from 2003 to 2004.

Fast Fact
Merck paid publisher Elsevier to produce a journal that looked like a peer-reviewed medical journal but was actually a marketing tool for Fosamax and other Merck products.

Samples of the journal surfaced in a civil suit against Merck for Vioxx. It included only positive conclusions about the drugs. There were 12 articles dedicated to Fosamax. Many of the supposed articles had no authors and few references.

Elsevier admitted that Merck had sponsored the publication and there were no disclosures to indicate it was sponsored by Merck. Critics said it was a ploy to trick doctors who might be influenced by the publication.

Please seek the advice of a medical professional before making health care decisions.

Related Pages
Michelle Llamas, Senior Content Writer
Written By Michelle Llamas Senior Writer

Michelle Llamas has been writing articles and producing podcasts about drugs, medical devices and the FDA for seven years. She specializes in fluoroquinolone antibiotics, vaccines and products that affect women’s health such as Essure birth control, transvaginal mesh and talcum powder. Michelle collaborates with experts, including board-certified doctors, patients and advocates, to provide trusted health information to the public. Some of her qualifications include:

  • American Medical Writers Association (AMWA) Engage Committee and Membership Committee member
  • Centers for Disease Control and Prevention (CDC) Health Literacy certificates
  • Original works published or cited in The Lancet, British Journal of Clinical Pharmacology and the Journal for Palliative Medicine
Edited By
Kevin Connolly
Kevin Connolly Managing Editor
Medically Reviewed By
Dr. Joseph Palermo
Dr. Joseph Palermo Osteopathic Medicine

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