Review Question - QID 105827

Although lithium is the prefered first line treatment for bipolar disorder, renal impairment increases the risk of lithium toxicity, and thus is a contraindication for lithium therapy.

Lithium, which is a first line therapy for bipolar disorder, is notorious for having a narrow therapeutic window. Side effects include: tremor, sedation, acne, heart block, hypothyroidism, nephrogenic diabetes insipidus, and leukocytosis. Renal failure, hyponatremia, and dehydration all increase likelihood of lithium toxicities, and are thus contraindications for lithium therapy. Other first line medications for bipolar disorder include valproate or carbamazepine. Lamotrigine and atypical antipsychotics are second line therapy for bipolar disorder.

In a review of bipolar disorder, Price and Marzani-Nissen stress the importance of continuing maintenance mood stabilizers between episodes of mania, hypomania, or depression. They remind physicians that the five-year relapse rate is greater than 70% after the onset of the first episode.

In a meta-analysis of lithium toxicity in the literature, McKnight et al. found that in patients on chronic lithium therapy, GFR was decreased by 6.22 mL/min (95% CI 2.20 - 14.65) and TSH was increased by 4.00 iU/mL (95% CI 3.90 - 4.10).

Figure A shows an EKG with the finding of prolonged QTc. Ondansetron, quetiapine, and haloperidol are commonly used QTc-prolonging medications.

Incorrect Answers:
Answer 1: Atypical antipsychotics such as olanzapine should be used with caution in patient's with diabetes mellitus.
Answer 2: Hypertension is not a contraindication for lithium therapy.
Answer 3: Atypical antipsychotics such as quetiapine should be used with caution in patients with prolonged QT.
Answer 4: Valproate is contraindicated in patients with liver disease.