People who are taking lithium for bipolar disorder may develop lithium toxicity because the effective dose is close to the toxic dose. To prevent and detect this, healthcare providers usually require regular blood tests that measure the lithium level in the blood. Based on these tests, your dosage may be adjusted. Symptoms of toxicity include shakiness, increased urination, and coordination problems.
Lithium (Eskalith®, Eskalith CR®, Lithobid®) is a prescription medication approved to treat bipolar disorder. While it is one of the more effective and affordable bipolar medications available, it can cause significant toxicity. All medications can produce toxicity if taken in high enough doses. For most medications, however, the effective dose is much lower than the toxic dose (and toxicity is rare, except in cases of an overdose). With other medications, such as lithium, the effective dose is close to the toxic dose, and toxicity is more common.
In order to prevent and detect lithium toxicity, healthcare providers usually require regular blood tests that measure the level of lithium in your blood. Based on your lithium level (as well as any lithium side effects or symptoms of bipolar disorder you are experiencing), your healthcare provider may adjust your lithium dosage. Unfortunately, some people will experience lithium toxicity even if their levels are within the recommended range. In general, levels greater than 1.5 milliequivalents per liter (mEq/L) increase the risk of lithium toxicity and require medical attention.
In order for your lithium blood level to be meaningful, it should be taken at a certain time, preferably just before a dose of lithium (about 8 to 12 hours after the previous dose). Levels taken at other times are typically less useful, as your dose is less stable during these times.