Lithium Depression Side Effects

Lithium is one of many medications used in the treatment of depression. And while it can be an effective treatment, the potential for side effects is high. Until the right dosage amount is found, patients can experience changes in central nervous system function, as well as kidney function. Regularly scheduled blood level checks are needed to determine proper dosage amounts.

Identification

• Prescribed to treat manic-depressive disorder as well as depression, lithium can be administered in tablet, capsule or syrup form. Dosage levels vary depending on the person's body chemistry. The right amount is determined by the amount of the substance found in the blood. Discovering the correct dosage may require a series of adjustments. On average, adults require anywhere from 300 to 400 milligrams taken two to three times a day.

Chemical Mechanism

• Lithium carbonate is the most commonly used form of the drug. It has a powerful chemical effect on the body. Lithium carries a positive chemical charge similar to the elements sodium or potassium, with effects taking place at the cellular level. Chemicals like sodium, potassium and calcium play essential roles in cell function. Lithium interacts with chemicals both inside and outside the cell, with a direct effect on cellular functions. People taking lithium for depression typically feel the effects of the drug within a week's time, but its full effects don't appear until two to three weeks later.

Central Nervous System

• One area in which lithium's side effects become particularly powerful is in the body's central nervous system (CNS). Chemicals in CNS cells, called neurotransmitters, act as messengers that communicate nerve impulses throughout the body. Neurotransmitter imbalances are present in those who experience symptoms of depression. Lithium works by interfering with these chemical reactions to create a more balanced chemistry inside the body. However, until the right dosage is found, side effects like hand tremors, changes in heart rate, sleep disturbances and dizziness may occur.

Kidney Function

• As lithium's effects on cell function impact sodium and potassium levels within the body, some potential side effects experienced are related to kidney processes. A condition called nephrogenic diabetes insipidus is a common effect that occurs in as many as 50 percent of those who start taking lithium. It's a condition in which the kidneys become unable to conserve water. Symptoms of nephrogenic diabetes insipidus are frequent urination of diluted, or watery urine, and drinking excessive amounts of water. These effects are reversible once a person stops taking lithium, however, they can continue for as long as a year afterward. Also of concern are possible drug reactions that can occur when lithium is taken with other medications. Anti-inflammatory drugs like naproxen, ibuprophen and indomethicin may interfere with the kidney's ability to eliminate lithium, leading to elevated levels in the blood and resulting side effects.

Warning

• The most dangerous side effect of lithium treatment is the risk of blood toxicity. Symptoms of blood toxicity include slurred speech, confusion, coma, appetite loss and fatigue. Persons who are on the drug require regular blood level checks to ensure blood levels are nontoxic. Finding the right dosage amount requires blood levels to measure at just under the toxic level. This is considered the therapeutic dosage amount where lithium is most effective at relieving depression symptoms. As a result, it's not uncommon for multiple adjustments to be made before the right dosage amount is found. Lithium's interactions on the cellular level can also affect sodium levels, as well as the body's hydration needs. Any activities that deplete water, or salt reserves, in the body may lead to further side effects. Proper hydration is essential when exercising or in cases where sickness places a strain on the body's hydration needs.