Gingival Hyperplasia

• People who need high doses of Dilantin may have some problems with long-term use, mainly affecting appearance. Up to 40 percent of patients experience an overgrowth of their gums, more common in children than adults. This can be minimized by vigorous brushing, daily flossing and treatments by dentists.
  
  

Other Appearance Effects

• Other long-term use side effects include excessive hair growth on the face or body, called hirsutism, as well as a coarsening of facial features and acne.
  
  

Bone Weakening

• Long-term use of Dilantin also is associated with weakening of the bones, though this is more likely if the drug is combined with other anti-seizure medications. Patients can decrease this risk by taking vitamin D supplements, eating calcium-rich foods and exercising regularly.
  
  

Neuropathy

• People taking Dilantin for many years also can develop sensory peripheral polyneuropathy, or nerve damage, which can cause pain, tingling or numbness in the feet and legs.
  
  

Cerebellum Atrophy

• Long-term Dilantin use is associated with atrophy to the brain cerebellum, but it is rare for people to experience significant problems related to this side effect.
  
  

Dyskinesia

• Additionally, people taking Dilantin for a long time may begin having problems with dyskinesia, characterized by involuntary movements such as tremors and twitches.