As epilepsy is generally a lifelong condition, prolonged use of anti-epilepsy drugs (AEDs) may cause side effects not seen with short-term use. Dilantin is the common brand name of phenytoin, one of the oldest and most frequently used AEDs. Some prolonged side effects of Dilantin use may be simply troublesome, while others may be irreversible or even life-threatening.
Changes in Appearance
Most of the common effects of long-term Dilantin use involve the appearance. Gingival hyperplasia is a condition that causes the gums to grow, resulting in the appearance of smaller teeth and possible dental problems. It is a common effect that may be related to the size of the dose and is more common in children who take Dilantin. Problems associated with gingival hyperplasia may be minimized by regular dental care and good oral hygiene. This effect often resolves itself if Dilantin is discontinued.
Acne is a common long-term effect that may be prevented by using traditional acne treatments. Acne is usually reversible. Hirsutism, or the unwanted growth of hair, is more common in people with light complexions. It may be an irreversible change that can require the use of hair removal treatments. Another permanent long-term effect of Dilantin use may be coarsening of facial features or masculinization, which can include thickening of the skin and facial bones.
Effects on the Nervous System and Brain
Some patients report sensory peripheral polyneuropathy, or the sensation of nerve-related pain, in the extremities, including the hands and feet, from long-term use of Dilantin. This disorder may be extremely painful or restrict movement. In some patients, it may be permanent as nerves that have been damaged do not easily regenerate. Cerebellar atrophy, or loss of brain tissue in the cerebellum, may be caused by long-term use of Dilantin, particularly with use of high doses. This condition may affect both motor and cognitive functioning. Although generally irreversible, it is usually not severe enough to pose significant limits in function.
Osteomalacia
Prolonged use of Dilantin has been shown to result in higher-than-normal rates of osteomalacia, a softening of the bones. This condition is more likely if other medications for seizure disorder are used as well. Patients who are taking Dilantin for a long period of time are often advised to eat foods high in calcium and vitamin D and to stay physically active. Calcium and vitamin D supplements may also be recommended. However, calcium should not be taken within two hours of Dilantin, as the calcium may inactivate the active ingredient, phenytoin.
Lymphadenopathy
According to Pfizer, the manufacturer of Dilantin, some reports have suggested that the medication may cause the development of lymphadenopathy. This condition may include benign lymph node hyperplasia and pseudolymphoma, along with the more life-threatening conditions of lymphoma and Hodgkin's disease. If fever, rash and swollen or tender lymph glands are noted, a physician should be consulted. In most confirmed cases of lymphadenopathy, Dilantin is discontinued and an alternative medication used.
