Some people respond well to maintenance treatment and have no further episodes, while others may have moderate mood swings that lessen as treatment continues. Some people may continue to have episodes that are diminished in frequency and severity. Unfortunately, some bipolar patients may not be helped at all. Response to treatment with lithium varies, and it cannot be determined beforehand who will or will not respond to treatment.
Regular blood tests are an important part of treatment with lithium. A lithium level must be checked periodically to measure the amount of the drug in the body. If too little is taken, lithium will not be effective. If too much is taken, a variety of side effects may occur. The range between an effective dose and a toxic one is small.
A lithium level is routinely checked at the beginning of treatment to determine the best lithium dosage for the patient. Once a person is stable and on maintenance dosage, a lithium level should be checked every few months. How much lithium a person needs to take may vary over time, depending on how ill he is, his body chemistry, and his physical condition.
Anything that lowers the level of sodium (table salt is sodium chloride) in the body may cause a lithium buildup and lead to toxicity. Reduced salt intake, heavy sweating, fever, vomiting, or diarrhea may do this.
An unusual amount of exercise or a switch to a low-salt diet are examples. It’s important to be aware of conditions that lower sodium and to share this information with the doctor. The lithium dosage may have to be adjusted.
When a person first takes lithium, he may experience side effects, such as drowsiness, weakness, nausea, vomiting, fatigue, hand tremor, or increased thirst and urination. These usually disappear or subside quickly, although hand tremor may persist. Weight gain may also occur. Dieting will help, but crash diets should be avoided because they may affect the lithium level. Drinking low-calorie or no-calorie beverages will help keep weight down.
Kidney changes, accompanied by increased thirst and urination, may develop during treatment. These conditions that may occur are generally manageable and are reduced by lowering the dosage.
Because lithium may cause the thyroid gland to become underactive (hypothyroidism) or sometimes enlarged (goiter), thyroid function monitoring is a part of the therapy. To restore normal thyroid function, thyroid hormone is given along with lithium.