The side effects of lithium used to treat bipolar disorder include nausea, dizziness, muscle weakness and tiredness, according to WebMD. Lithium can also cause the patient to feel dazed. Fortunately, these side effects wear off as the patient continues to use the drug.
Side effects that persist include tremor, thirst and the frequent need to urinate, claims WebMD. Patients can also develop unwanted weight gain and edema. Skin diseases such as psoriasis are exacerbated by lithium.
Pregnant women and women who are breastfeeding should not take lithium, according to WebMD. Lithium is toxic to the fetus and heightens the risk of birth defects. A woman who takes lithium when she is pregnant must be carefully monitored by her doctor. Lithium can also pass into breast milk.
People who have heart or kidney problems also need to be closely monitored if they take lithium, says WebMD. Lithium is suspected of causing heart arrhythmias, and since the kidneys flush lithium out of the body, the patient's dosage needs to be adjusted. Lithium might also make thyroid problems worse.
Patients who are considering surgery need to stop taking lithium well before the surgery is scheduled, claims WebMD. Lithium works by altering neurotransmitters, which affects the central nervous system.