Alendronic acid, sold under the brand name Fosamax among others, is a bisphosphonate medication used to treat osteoporosis and Pagets disease of bone. It is taken by mouth. Use is often recommended together with vitamin D, calcium supplementation, and lifestyle changes.Common side effects (1 to 10% of patients) include constipation, abdominal pain, nausea, and acid reflux. Use is not recommended during pregnancy or in those with poor kidney function. Alendronic acid works by decreasing the activity of cells that break down bone.Alendronic acid was first described in 1978 and approved for medical use in the United States in 1995. It is available as a generic medication. In 2019, it was the 96th most commonly prescribed medication in the United States, with more than 7 million prescriptions. Medical uses
Prevention and treatment of female osteoporosis
Treatment of male osteoporosis
Prevention and treatment of corticosteroid-associated osteoporosis together with supplements of calcium and vitamin D
Pagets disease

Contraindications
Alendronate should not be used in:

Acute inflammations of the gastrointestinal tract (esophagitis, gastritis, ulcerations)
Clinically manifested osteomalacia
Certain malformations and malfunctions of the esophagus (strictures, achalasia)
Inability to stand, walk, or sit for 30 minutes after oral administration
Renal impairment or chronic kidney disease as evidenced by a creatinine clearance below 30ml/min
Hypersensitivity to alendronate or another ingredient in the product
Hypocalcemia
Pregnancy and breastfeeding
Patients below 18 yrs. of age, as no clinical data exists for this population

Side effects
Gastrointestinal tract:
Ulceration and possible rupture of the esophagus; this may require hospitalization and intensive treatment. Gastric and duodenal ulceration may also occur.
Craniodiaphyseal dysplasia (CDD), also known as lionitis, is an extremely rare autosomal recessive bone disorder that causes calcium to build up in the skull, disfiguring the facial features and reducing life expectancy. These calcium deposits decrease the size of cranial foramina, and can decrease the circumference of the cervical spinal canal. In the few cases recorded, most died in childhood. Cause
The underlying genetics are uncertain. Diagnosis
Among the medical signs are dacryocystitis, seizures, intellectual disability, and paralysis, each of which is a complication resulting from the diminutive foramina. A common sign reported as a result of the disease has been widely spaced eyes. Society
Peter Bogdanovichs 1985 drama film Mask drew public attention to the case of Roy L. "Rocky" Dennis, an American boy who died of the disorder in 1978.In the American medical drama Greys Anatomy episode "Yesterday", Jesse Plemons plays a teenage boy with lionitis. The main character of the two-issue comic book miniseries Friday the 13th: How I Spent My Summer Vacation by Wildstorm Productions is a 13-year-old boy with the disorder. In the anthology television series American Horror Story season 1, Beauregard, the brother of Tate and Adelaide, had lionitis. See also
Leontiasis ossea

References
External links
Craniodiaphyseal dysplasia at orpha.net