Lithium carbonate, commonly shortened to lithium, is a medication used in the treatment of a disease that was once called manic-depressive illness. Known as bipolar disorder, this condition results in mood swings that can range from mild to severe. Lithium helps to reduce the frequency and intensity of the manic phase of bipolar disorder, although the exact mechanism by which it does this is unknown. One of lithium’s less common side effects is an increase in calcium levels. Lithium should only be used under the supervision of a health care professional.
Calcium
Calcium is so important to survival that if your calcium intake is insufficient, your body will pull this mineral out of the bones to maintain blood levels within the narrow range of normal. Calcium helps regulate expansion and contraction of blood vessels, is used in enzymes and helps your blood clot. Cells in the skeletal muscles and nerves use a calcium channel in their cell membranes to allow calcium concentrations to change rapidly so your muscles can contract.
Hypercalcemia
When your calcium levels get too high, the condition is called hypercalcemia. Hypercalcemia is usually seen when you have taken too much calcium in supplement form, but can also result from medication side effects. This condition can range from mild, with symptoms such as dry mouth, loss of appetite, nausea and frequent urination, to more severe cases in which confusion, delirium and even coma result. If untreated, severe hypercalcemia can result in death.
Lithium and Calcium
Lithium blocks calcium entry into some body cells because it competes for the same transportation mechanisms that calcium uses. Lithium may also prevent secretion of the parathyroid hormone that controls calcium levels, so even when calcium levels in the blood are high, the parathyroid gland sends signals to release more calcium from bones. Lithium also prevents or decreases production of a substance called inositol monophosphate. When IMP is depleted, there is less calcium to help shut off the excess parathyroid hormone.
Lithium and Hypercalcemia
Hypercalcemia is an unusual side effect of lithium. A case report of a patient who suffered hypercalcemia after lithium administration was presented at the 1999 annual meeting of the Association of Medicine and Psychiatry. The doctors treating the patient determined that lithium had affected the patient’s parathyroid glands, which control calcium levels. The physicians noted this condition is so rare that only five cases had been reported between 1991 and 1999.
Member Comments