by Nicole Evans M.D.

Created on: May 06, 2010   Last Updated: May 09, 2010

Lithium is the first line medical therapy for prevention of the manic episodes that occur in individuals with bipolar disorder.  In children, lithium is occasionally used off label in the treatment of post-traumatic stress disorder, aggression and conduct disorder.

Lithium is a potentially lethal medication at toxic doses, and can cause numerous adverse effects at therapeutic levels.  There are specific concerns regarding the side effects of lithium in individuals with various medical conditions including heart disease, impaired kidney function, thyroid disease, and dehydration from any cause.

Disease-related concerns in individuals taking lithium:

* Cardiovascular disease: Lithium should be used with caution in people who have mild to moderate heart disease.  Known cardiac side effects of lithium that could have dangerous consequences in people with cardiovascular disease include bradycardia (slow heart rate), cardiac arrhythmia, reversible flattened or inverted T waves on an electrocardiogram or “EKG”, and hypotension (low blood pressure).

* Renal impairment: Lithium should be used with extreme caution in patients with mild to moderate impairment of kidney function.  Lithium levels should be monitored frequently in all individuals on lithium.  Those people with reduced kidney function should have their dose of lithium adjusted based on their estimated creatinine clearance (Clcr) as follows:

            Clcr 10-50 mL/minute: Administer 50% to 75% of the normal lithium dose.

            Clcr <10 mL/minute: Administer 25% to 50% of the normal dose of lithium.

* Thyroid disease: Individuals with thyroid disease should use lithium with caution.  Thyroid side effects can occur in both men and women on lithium and may result in one of three thyroid abnormalities: hyperthyroidism, hypothyroidism or euthyroid goiter (enlargement of the thyroid with normal levels of thyroid stimulating hormone [TSH], and the thyroid hormones T4 and T3).

* Dehydration: Prolonged or severe fluid losses can significantly increase the toxicity of lithium.  Thus, lithium should be used with caution in patients with medical conditions that cause significant fluid losses such as long periods of sweating, diarrhea, or a lengthy fever.  In some situations the dose of lithium in these patients may need to be reduced, or even discontinued, temporarily.

As discussed above, there are numerous disease-related concerns regarding the side effects of lithium.  Individuals starting lithium who have pre-existing medical conditions, or those who develop medical conditions while on lithium, should work closely with their physician to avoid these potentially dangerous adverse effects.

Source: LexiDrugs, LexiComp Online. 2010.

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