https://en.wikipedia.org/wiki/Lithium_%28medication%29Common side effects include increased urination, shakiness of the hands, and increased thirst. Serious side effects include hypothyroidism, diabetes insipidus, and lithium toxicity. Blood level monitoring is recommended to decrease the risk of potential toxicity. If levels become too high, diarrhea, vomiting, poor coordination, sleepiness, and ringing in the ears may occur.
Hypothyroidism
Most patients treated with lithium carbonate show elevated thyroid stimulating hormone levels in response to injections of thyrotropin-releasing hormone.[30] According to an Australian study, "The incidence of hypothyroidism is six-fold higher in people on lithium as compared to the general population. Hypothyroidism in turn increases the likelihood of developing clinical depression."[28]
Because lithium competes with the receptors for the antidiuretic hormone in the kidney, it increases water output into the urine, a condition called nephrogenic diabetes insipidus. Clearance of lithium by the kidneys is usually successful with certain diuretic medications, including amiloride and triamterene.[31] It increases the appetite and thirst ("polydypsia") and reduces the activity of thyroid hormone (hypothyroidism).[32][33][34][35] The latter can be corrected by treatment with thyroxine and does not require the lithium dose to be adjusted. Lithium is also believed to permanently affect renal function, although this does not appear to be common.[36]
Teratogenicity
Lithium is also a teratogen, causing birth defects in a small number of newborn babies.[37] Case reports and several retrospective studies have demonstrated possible increases in the rate of a congenital heart defect known as Ebstein's anomaly, if taken during a woman's pregnancy.[38] As a consequence, fetal echocardiography is routinely performed in pregnant women taking lithium to exclude the possibility of cardiac anomalies. Lamotrigine seems to be a possible alternative to lithium in pregnant women.[38] Gabapentin[39] and clonazepam[40] are also indicated as antipanic medications during the childbearing years and during pregnancy. Valproic acid and carbamazepine also tend to be associated with teratogenicity.
Dehydration
Dehydration in people taking lithium salts can be very hazardous, especially when combined with lithium-induced nephrogenic diabetes insipidus with polyuria. Such situations include preoperative fluid regimen or other fluid inaccessibility, warm weather conditions, sporting events, and hiking. Dehydration can result in lithium retention, which can increase lithium levels.
Another danger is that rapid hydration with a large volume of plain water may very quickly produce hyponatremia, with its danger of low sodium concentrations in plasma. Hyponatremia can also cause lithium retention and thus increased lithium levels.