Lithium

Understanding Lithium Medication

Lithium is a mood-stabilizing medication primarily prescribed for the treatment of bipolar disorder. It can help reduce the severity and frequency of mania, and may also be effective in preventing depressive episodes associated with bipolar disorder.

Chemical Composition and Form

Lithium is available in several forms, including lithium carbonate and lithium citrate. The formulations come in immediate-release and extended-release tablets, as well as in liquid form.

Therapeutic Indications

Beyond its primary use in bipolar disorder, lithium may be prescribed for major depressive disorder when other treatments have failed. Off-label uses can include treatment of certain forms of cluster headaches and impulse control disorders.

Dosage and Administration

The dosage of lithium varies based on individual need and response to the medication. Regular monitoring of blood lithium levels is crucial to ensure dosages are within the therapeutic range and to prevent toxicity. The drug is usually taken one to three times per day with or without food.

Pharmacokinetics and Metabolism

Lithium is absorbed in the gastrointestinal tract. Its absorption can be influenced by dietary sodium intake. Lithium is not metabolized and is excreted unchanged in the urine. Renal function is an important determinant of lithium clearance from the body.

Drug Interactions and Contraindications

Lithium has significant drug interactions with diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), and certain antihypertensive medications. Contraindications include severe renal or cardiovascular disease, dehydration, or sodium depletion.

Monitoring Lithium Levels

Therapeutic lithium levels typically range from 0.6 to 1.2 mEq/L. Levels should be checked 5-7 days after starting treatment or after a dosage change, and every 3 to 6 months during maintenance therapy. Kidney and thyroid function tests are also required regularly, as lithium can affect both organs.

Common Side Effects

Side effects may include gastrointestinal distress, muscle weakness, fine tremor, polyuria, and mild thirst. Adverse reactions usually occur at higher lithium concentrations and may necessitate dosage adjustments or discontinuation.

Long-term Use Considerations

Chronic use of lithium can lead to hypothyroidism or hyperparathyroidism, necessitating ongoing thyroid monitoring. Prolonged use can also potentially cause renal impairment or renal failure, underscoring the importance of periodic kidney function tests.

Lithium and Pregnancy

Lithium can be teratogenic, particularly during the first trimester of pregnancy. If a woman becomes pregnant while taking lithium, the risks and benefits of continuing treatment should be evaluated promptly.

Patient Counseling Points

Patients should be advised to maintain a consistent sodium intake and hydration level to prevent lithium toxicity. Warning signs of toxicity include severe tremors, confusion, ataxia, and vomiting, necessitating immediate medical attention.

Storage and Handling

Lithium should be stored at room temperature, away from light and moisture. The medication should be kept in its original container and out of reach of children.

Disposal of Unused Lithium

Unused lithium medication should be disposed of properly, in accordance with local regulations, to prevent accidental exposure or environmental damage.