Prescription:

Fosamax (Alendronate) is used to prevent and treat osteoporosis in women who have undergone menopause, in men and women who are taking glucocorticoids (corticosteroids; a type of medication that may cause osteoporosis), and to treat Paget's disease of the bone (a condition in which the body replaces healthy bones with weak bones).

It works by preventing the breakdown of bone and by increasing the strength and structure of the bone.

Why is this drug prescribed?

Fosamax tablets contain the active ingredient alendronic acid, which is a type of drug called a bisphosphonate. Alendronic acid tablets are also available without a brand name, ie as the generic drug. Bisphosphonates are drugs that prevent the breakdown of bone. Bone is not a static structure. It is continually shaped, reformed and rebuilt by cells called osteoblasts and osteoclasts. These cells continously deposit and remove calcium and phophorous, stored in a protein network that makes up the structure of the bone. Old bone is broken down by the osteoclasts and new bone is formed by the osteoblasts. In women at the menopause, blood levels of the female hormone oestrogen start to decrease. This results in an increase in bone breakdown by the osteoclasts, which can lead to a loss of bone density. Bone loss is particularly rapid for the first ten years after the menopause and it may lead to the development of osteoporosis - a condition in which the bones become weak and brittle and break more easily. Osteoporosis can also occur in men and as a result of long-term treatment with corticosteroid drugs such as prednisolone. Other risk factors include smoking, a family history of osteoporosis, early menopause and thin body build. Alendronic acid is used both to prevent bone loss in people who are at risk of developing osteoporosis, and to prevent fractures in people who already have osteoporosis. The drug works by binding very tightly to the bone and preventing the calcium being removed by the osteoclasts. This stops the osteoclasts from breaking down the bone, which helps to keep the bones strong and less likely to break. As this drug slows bone turnover and so prevents calcium being rebsorbed from the bones into the blood, it can cause the amount of calcium in your blood to fall too low. If your dietary intake of calcium and vitamin D is low, your doctor may ask you to take supplements to prevent this.

Treatments

* Prevention and treatment of osteoporosis in women who have passed the menopause * Treatment of osteoporosis in men * Prevention and treatment of osteoporosis caused by long-term treatment with corticosteroids such as prednisolone.

What side effects can this drug cause?

* Disturbances of the gut such as diarrhoea, constipation, nausea, vomiting or abdominal pain * Indigestion * Excess gas in the stomach and intestines * Bloating * Difficulty or pain when swallowing * Acid regurgitation * Ulceration of the food pipe * Headache * Pain in joints, muscles or bones * Inflammation of the food pipe * Skin reactions such as rash or itching * Flushing of the skin due to widening of the small blood vessels * Inflammation of the stomach * Low blood calcium level * Ulceration, bleeding or perforation of the stomach or intestines * Dark colored, tarry stools, due to the presence of blood altered by the intestinal juices * Inflammation of the front parts of the eye