Fosamax - Precautions | Use | Interactions

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Fosamax is a medicine containing alendronate and belongs to a group of medicines called bisphosphonates. It is used for prevention of osteoporosis in postmenopausal women. Postmenopausal women have decreased synthesis of estrogen (female hormone) which inter alia has a role in the prevention of bone loss. Decreased secretion of estrogen increases bone loss that causes a disease called osteoporosis. Postmenopausal women are at increased risk of hip and wrist fracture, but application of Fosamax reduces that risk.


Given that there are reported cases of esophagus damage (esophagitis) in patients who received this drug1. Fosamax should not be used in patients who already have esophagus damage or have difficulty swallowing. In order to reduce the risk of damage to the esophagus, it is necessary to take this drug in a standing position and to stand for at least a half an hour after taking Fosamax. Swallow the pill with at least 500 ml of regular water because in this way you'll prevent retention of the pill in the esophagus.

Cases of auditory hallucinations and visual disturbances have also been reported. 2 If you notice hallucinations in the sense that you hear sounds / voices that are not there or if you notice impaired vision, contact your doctor immediately.

Inflammation of the joints (polyarthritis) was reported in two case-reports.3,4 If you notice joint pain or their swelling, contact a physician immediately.

Fosamax should be very carefully used in the following conditions:

  • In patients with nephritis or other kidney diseases. Cases of interstitial nephritis after Fosamax use have been reported.5
  • In patients with hypocalcemia. Cases of hypocalcemia have been reported in patients who are treated with this drug. 6 Hypocalcemia is generally mild or moderate, although severe forms of this unwanted effect have also been reported. Taking the supplements of vitamin D and calcium while on Fosamax therapy is recommended.
  • In patients who have problems with their teeth or jaw. There have been reports of osteonecrosis of the jaw in patients who have used this drug.7
  • In patients who are undergoing chemotherapy.

Fosamax, pregnancy and lactation

Given that Fosamax is used only in postmenopausal women it should never be used during pregnancy and lactation.

But, if you think you are pregnant, then you should not apply this medicine.

How to use

It is very important to apply Fosamax as follows:

  • Take the pill always on the same day of the week and at the same time
  • Do not take your medicine with mineral water or juices. You can use only the regular (normal) water.
  • Do not take eat or drink anything (except normal water) for two hours after taking the pill. Food and beverages reduces the effectiveness of the Fosamax.
  • Take the pill in the morning on an empty stomach
  • Swallow the pill with at least 500 ml of water
  • After taking the drug, you must not lie down, but you must be in an upright position (standing, walking or sitting - it is best to walk)

If you take Fosamax as recommended, you'll reduce the risk of esophagus damage.

Fosamax is taken at a dose of 70 mg once a week.


Fosamax should not be used simultaneously with the following medicines:

  • Deferasirox - a drug used to remove excess iron in patients who have received blood transfusions. Co-administration of these two drugs increases the risk of gastrointestinal bleeding.
  • Non-steroidal anti-inflammatory drugs (e.g. ibuprofen, diclofenac, ketoprofen, flurbiprofen and acetyl salicylic acid). These drugs increase the risk of bleeding in the gastrointestinal tract, and should not be administered concurrently with the Fosamax.

Side effects

Fosamax may cause the following side effects:

  • Damage to the esophagus (difficulty in swallowing, or pain in the chest)
  • Stomach pain
  • The feeling of discomfort in the stomach
  • Alopecia
  • Pruritus
  • Gastric or duodenal ulcer
  • Ulcers in the mouth
  • Arthritis
  • Black-colored stools
  • Blurred vision
  • Flu-like symptoms
  • Hypocalcemia
  • Hyponatremia


  1. NCBI link 1
  2. NCBI link 2
  3. NCBI link 3
  4. NCBI link 4
  5. NCBI link 5
  6. NCBI link 6
  7. NCBI link 7

Information on this website are provided for educational purposes only and are not intended for medical advice, diagnosis or treatment.

If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.

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