Review Question - QID 106839

The patient's bipolar disorder is being treated with lithium, which can cause hypothyroidism as indicated by the elevated TSH and decreased free and serum T4.

Lithium is a mood stabilizer used to treat bipolar disorder. Although the exact mechanism is unknown, it may be related to the inhibition of phosphoinositol recycling in neurons. Lithium is otherwise primarily utilized to prevent and treat acute mania. It has a very narrow therapeutic index; thus, it requires blood monitoring. Side effects of lithium include: hypothyroidism, polyuria, heart-block, sedation, tremor, acne, edema, and leukocytosis.

Griswold and Pessar review bipolar disorder, which is commonly diagnosed in individuals between the ages of 18-24. Signs and symptoms of the disorder include mania, hypomania, and psychosis. Treatment involves a mood stabilizer such as lithium, valproic acid, or carbamazepine.

Bocchetta and Loviselli recommend thyroid function tests before lithium treatment is begun and again annually. If elevated TSH levels are seen, then retesting should be done at shorter intervals, such as 4-6 months. If abnormalities are seen, lithium should not be stopped, but the patient should be referred to an endocrinologist for further testing.

Illustration A is a diagram depicting the signs and symptoms of hypothyroidism.

Incorrect Answers:
All of these medications can also be used to treat bipolar disorder.
Answer 1: Side effects of valproic acid are pancreatitis, hepatotoxicity, tremor, and weight gain.
Answer 3: Side effects of carbamazepine are diplopia/ataxia, agranulocytosis, aplastic anemia, megaloblastic anemia, hepatotoxicity, SIADH, and Stevens-Johnson syndrome.
Answer 4: A side effect of lamotrigine is Steven-Johnson syndrome.
Answer 5: Side effects of olanzapine are weight gain and metabolic syndrome.