Alendronate is a prescription oral drug used to treat osteoporosis and other disorders that cause bones to become weak and brittle. It works by inhibiting the action of osteoclasts, cells that trigger the breakdown of bone tissue. As a result, bone tissue is able to retain important minerals and the risk of accidental fractures is significantly decreased. The drug is commonly sold under the brand name Fosamax®, but generic varieties are widely available. Alendronate comes in tablet form and a liquid solution that can be mixed with water.
Medications that contain alendronate are classified as biophosphonates, drugs that block osteoclast activity in the body. Osteoclasts normally regulate bone density and size by removing excess minerals, a process called bone resorption. Alendronate prevents resorption by binding to the cellular sites where osteoclasts are activated. Once bone resorption is halted, minerals such as calcium are replenished and tissue can become stronger and harder. It usually takes several months for biophosphonates to produce noticeable changes in bone density.
Alendronate is primarily used to combat bone loss from osteoporosis in older adults. The medication may also be prescribed to people who suffer from a condition known as Paget's disease. People with Paget's disease experience painful physical deformities due to somewhat spontaneous bone death and unusual regrowth. When alendronate is taken as directed by doctors, both osteoporosis and Paget's disease can be effectively managed in most patients.
There is little risk of adverse side effects when taking alendronate, but some patients experience mild bouts of stomach upset, nausea, and constipation. Less commonly, the drug can cause chest pains, jaw soreness, and vomiting. Allergic reactions are rare, but potentially serious. A person who experiences a widespread skin rash, dizzy spells or breathing difficulties after taking the drug should visit the emergency room immediately.
Doctors are careful when prescribing alendronate to minimize the risk of negative side effects and drug interactions. Physicians generally start patients on low doses of the drug and gradually increase dosage amounts over the course of several weeks. Most patients are instructed to take a single daily dose of 10 milligrams, but weekly 70 milligram doses are also available. Exact dosing amounts can vary based on a patient's specific condition, age, and tolerance of the drug. Since both osteoporosis and Paget's disease are chronic conditions, people usually need to remain on a drug regimen for the rest of their lives to prevent recurring bone problems.