context: Lithium ( Eskalith, Lithobid) is one of the most widely used and studied medications for treating bipolar disorder. Lithium helps reduce the severity and frequency of mania. It may also help relieve or prevent bipolar depression. Studies show that lithium can significantly reduce suicide risk. Lithium also helps prevent future manic and depressive episodes. As a result, it may be prescribed for long periods of time (even between episodes) as maintenance therapy. Lithium acts on a person's central nervous system (brain and spinal cord). Doctors don't know exactly how lithium works to stabilize a person's mood, but it is thought to help strengthen nerve cell connections in brain regions that are involved in regulating mood, thinking and behavior. It usually takes several weeks for lithium to begin working. Your doctor will order periodic blood tests during your treatment, because lithium can affect kidney or thyroid function. Lithium works best if the amount of the drug in your body is kept at a constant level. It is important that the lithium level in your body not be too low or too high. Your doctor will also probably suggest you drink eight to12 glasses of water or fluid a day during treatment and use a normal amount of salt in your food. Both salt and fluid can affect the levels of lithium in your blood, so it's important to consume a steady amount every day. The dose of lithium varies among individuals and as phases of their illness change. Although bipolar disorder is often treated with more than one drug, some people can control their condition with lithium alone. About 75% of people who take lithium for bipolar disorder have some side effects, although they may be minor. They may become less troublesome after a few weeks as your body adjusts to the drug. Sometimes, side effects of lithium can be relieved by tweaking the dose. However, never change your dose or drug schedule on your own. Do not change the brand of lithium without checking with your doctor or pharmacist first. If you are having any problems, talk to your doctor about your options. Common side effects of lithium can include: Hand tremor ( If tremors are particularly bothersome, dosages can sometimes be reduced, or an additional medication can help.) Increased thirst Increased urination Diarrhea Vomiting Weight gain Impaired memory Poor concentration Drowsiness Muscle weakness Hair loss Acne Decreased thyroid function (which can be treated with thyroid hormone) Notify your doctor if you suspect you may have persistent side effects from lithium or if you develop diarrhea, vomiting, fever, unsteady walking, fainting, confusion, slurred speech, or rapid heart rate. Tell your doctor about history of cancer, heart disease, kidney disease, epilepsy, and allergies. Make sure your doctor knows about all other drugs you are taking. Avoid products that are low in sodium (salt) since a low sodium diet can lead to excessively high lithium levels. While taking lithium, use caution when driving or using machinery and limit alcoholic beverages. People who take lithium also should consult with their doctor before taking nonsteroidal anti-inflammatory drugs ( NSAIDs) such as ibuprofen, because those medications can increase lithium levels. If you miss a dose of lithium, take it as soon as you remember it -- unless the next scheduled dose is within two hours (or six hours for slow-release forms). If so, skip the missed dose and resume your usual dosing schedule. Do not "double up" the dose to catch up. There are a few serious risks to consider. The drug has been linked to certain birth defects and should be used with caution in pregnant women, especially during the first three months of pregnancy. The safety of breastfeeding while taking lithium is controversial and should be discussed in advance with your doctor. Also, in some people, long-term lithium treatment can interfere with kidney function or lead to permanent kidney damage -- which is why periodic monitoring of blood tests to measure kidney functioning is important.