OVERVIEW
Lithium is a drug used as antipsychotics in the treatment of bipolar disorder. Occasionally, it can be used in other disorders to augment an antidepressant that does not adequately treat depression. This test measures the amount of lithium in the blood.
Bipolar disorder is a mental condition characterized by alternating periods of depression and mania. These periods may be as short as a few days or weeks or as long as months or years. During a depressive episode, those affected may feel sad, hopeless, worthless, and lose interest in daily activities. They may be fatigued but have trouble sleeping, experience weight loss or gain, have difficulty concentrating, and have thoughts of suicide. During a manic episode, those affected may be euphoric, irritable, have high energy and grandiose ideas, use poor judgment, and participate in risky behaviors. Sometimes affected people will have mixed episodes with aspects of both mania and depression. Bipolar disorder can affect both adults and children.
Lithium is prescribed to stabilize the mood swings of a person with bipolar disorder. It is often called a "mood stabilizer" and is sometimes prescribed for people with depression who are not responding well to other medications. Less commonly, lithium may be prescribed to prevent schizoaffective disorder and cluster headaches.
Because lithium is a relatively slow-acting drug, its effect on mood may take several weeks. Dosages of the drug are adjusted until blood concentrations are within a therapeutic range—the blood level range that achieves the desired effect and treats an individual's bipolar disorder. The actual amount of drug that it will take to reach this steady state will vary from person to person and may be affected by a person's age, general state of health, and other medications that they are taking.
Lithium levels are monitored on a regular basis because blood levels must be maintained within a narrow therapeutic range. Too little and the medication will not be effective; too much and symptoms associated with lithium toxicity may develop.
When To Get Tested?
When beginning treatment with lithium as the dose is adjusted to achieve therapeutic blood levels; at regular intervals to monitor lithium levels; as needed to detect sub-therapeutic levels or high (toxic) concentrations
- How is this test performed?
This test is performed on a blood sample. A syringe with a fine needle is used to withdraw blood from a blood vessel in your arm. The healthcare provider will tie an elastic band around your arm to make the blood vessels swell with blood. This makes it easier to withdraw blood. You may be asked to tightly clench your fist. Once the veins are clearly visible, the area is cleaned with an antiseptic solution and then the needle is inserted into the blood vessel to collect the sample. You will feel a tiny pinprick during the procedure. Blood sample once collected will then be sent to the laboratory.
- Is there any risk associated with this test?
There is no risk associated with the test. However, since this test involves a needle prick to withdraw the blood sample, in very rare cases, a patient may experience increased bleeding, hematoma formation (blood collection under the skin), bruising or infection at the site of needle prick.
- What are the symptoms of lithium toxicity?
Lithium toxicity may occur if the lithium concentration in your blood is higher than the therapeutic range. Symptoms of lithium toxicity include · Fatigue and drowsiness · Gastrointestinal problems including nausea, vomiting, diarrhea · Slurring of speech · Confusion · Dizziness · Loss of coordination · Muscle weakness · Restlessness · Shivering · Seizures Very high concentration of lithium in the blood may cause renal failure and even death.
INTERPRETATIONS
Therapeutic range: 0.6 to 1.2 mmol/L
The standard therapeutic range of lithium concentration may vary from person to person and is usually established at the beginning of the treatment.
Lower than the therapeutic range lithium concentration makes the drug ineffective in treatment.
Higher than the therapeutic range lithium concentration induces symptoms associated with lithium toxicity.
To measure lithium levels in the blood in order to determine the therapeutic level when just starting lithium medication; to maintain the therapeutic level or to determine lithium toxicity.
