A 43-year-old male with multiple medical problems including seizure disorder and mental illness comes to your office for the first time in order to establish a primary care physician. On routine physical examination, you notice the findings shown in the photo below. Which of the following is most likely responsible for the condition of this patient's teeth and gums?

Question

A 43-year-old male with multiple medical problems including seizure disorder and mental illness comes to your office for the first time in order to establish a primary care physician.  On routine physical examination, you notice the findings shown in the photo below.  Which of the following is most likely responsible for the condition of this patient's teeth and gums?

Quizplus · Accepted Answer

Gingival hyperplasia, like that shown in the photo above, is a common side effect of phenytoin. It occurs in 50% of patients who have had 3-4 months of phenytoin therapy. The mechanism of this side effect is associated with increased expression of platelet-derived growth factor (PDGF). When gingival macrophages are exposed to increased amounts of PDGF, they stimulate proliferation of gingival cells and alveolar bone. Gingival hyperplasia may regress after discontinuation of phenytoin. Phenytoin is an anticonvulsant effective in the treatment of grand mal (tonic-clonic) seizures, partial seizures, and status epilepticus. Phenytoin inhibits abnormal electrical activity of the brain by blocking voltage-gated sodium channels in neurons. Phenytoin has a narrow therapeutic index with a number of potential adverse effects: (Choice B) Lithium also has a narrow therapeutic index. Lithium toxicity is associated with neuromuscular excitability (irregular coarse tremors, fascicular twitching, rigid motor agitation, and ataxia). It may also cause nephrogenic diabetes insipidus, hypothyroidism, and cardiac conduction defects, but not gingival hyperplasia. (Choice C) The adverse effects of prednisone include hyperglycemia, weight gain, depression, fluid retention with edema, and osteoporosis. (Choice D) Cocaine blocks the re-uptake of norepinephrine, serotonin, and dopamine in the CNS. It can cause cardiac ischemia, hypertension, and seizures. Cocaine withdrawal is associated with severe depression. (Choice E) Methimazole inhibits thyroid hormone synthesis by suppressing the iodination and coupling of tyrosine. Side effects include edema, rash, and agranulocytosis. (Choice F) Clozapine is an atypical antipsychotic that is most helpful in treating the negative symptoms of schizophrenia. The most serious side effects of clozapine include agranulocytosis and seizures. Educational Objective: Gingival hyperplasia is a common side effect of phenytoin and is sometimes reversible when phenytoin is withdrawn. Phenytoin causes increased expression of platelet-derived growth factor (PDGF). When gingival macrophages are exposed to increased amounts of PDGF, they stimulate proliferation of gingival cells and alveolar bone. Phenytoin toxicity mainly affects the cerebellum and vestibular system, causing ataxia and nystagmus.

A 43-Year-Old Male with Multiple Medical Problems Including Seizure Disorder