Because of possible complications, lithium may either not be recommended or may be given with caution when a person has existing thyroid, kidney, or heart disorders, epilepsy or brain damage.

Women of childbearing age should be aware that lithium increases the risk of congenital malformations in babies born to women taking lithium. Special caution should be taken during the first three months of pregnancy.

Lithium, when combined with certain other medications, can have unwanted effects. Some diuretics (substances that remove water from the body) increase the level of lithium and can cause toxicity. Other diuretics, like coffee and tea, can lower the level of lithium.

Signs of lithium toxicity may include nausea, vomiting, drowsiness, mental dullness, slurred speech, confusion, dizziness, muscle twitching, irregular heartbeat and blurred vision. A serious lithium overdose can be life-threatening. Someone who is taking lithium should tell all the doctors, including dentists, he sees about all other medications he is taking.

With regular monitoring, lithium is a safe and effective drug that enables many people who otherwise would suffer from incapacitating mood swings to lead normal lives.

Anticonvulsants

Not all patients with symptoms of mania benefit from lithium. Some have been found to respond to another type of medication, the anticonvulsant medications that are usually used to treat epilepsy.

Carbamazepine (Tegretol) is the anticonvulsant that has been most widely used. Bipolar patients who cycle rapidly — that is, they change from mania to depression and back again over the course of hours or days, rather than months — seem to respond particularly well to carbamazepine.

Early side effects of carbamazepine, although generally mild, include drowsiness, dizziness, confusion, disturbed vision, perceptual distortions, memory impairment, and nausea. They are usually transient and often respond to temporary dosage reduction.

Another common but generally mild adverse effect is the lowering of the white blood cell count, which requires periodic blood tests to monitor against the rare possibility of more serious, even life-threatening, bone marrow depression.

Also serious are the skin rashes that can occur in 15 to 20 percent of patients. These rashes are sometimes severe enough to require discontinuation of the medication.

In 1995, the anticonvulsant divalproex sodium (Depakote) was approved by the Food and Drug Administration for bipolar disorder. Clinical trials have shown it to have an effectiveness in controlling manic symptoms equivalent to that of lithium; it is effective in both rapid-cycling and nonrapid-cycling bipolar.

Though divalproex can cause gastrointestinal side effects, the incidence is low. Other adverse effects occasionally reported are headache, double vision, dizziness, anxiety, or confusion. Because in some cases divalproex has caused liver dysfunction, liver function tests should be performed prior to therapy and at frequent intervals thereafter, particularly during the first six months of therapy.