Lithium (medication)

Lithium compounds, also known as lithium salts, are primarily used as psychiatric medications. They are most commonly used to treat bipolar disorder and major depressive disorder that does not improve following the use of antidepressants. Lithium is known to reduce the risk of suicide in these disorders and is administered orally.

Structural formula of lithium carbonate

3D model of lithium carbonate crystal structure

Lithium 300 mg tablets

Pharmacology

Lithium is classified as a mood stabilizer and has a unique mechanism of action in comparison to other psychiatric medications. While the exact mechanism is not fully understood, it is believed to affect various neurotransmitter systems, such as dopamine, serotonin, and glutamate, to stabilize mood fluctuations. Lithium also influences second messenger systems, including the inositol phosphate system and the protein kinase C pathway, which may contribute to its therapeutic effects.

Indications

Lithium is primarily prescribed for the following conditions:

• Bipolar disorder: Lithium is used in the treatment of both manic and depressive episodes, as well as for the maintenance treatment to prevent relapse.
• Major depressive disorder: In cases where patients do not respond to antidepressants, lithium may be used as an adjunctive therapy to enhance the effects of other medications.

Side Effects

Lithium may cause a range of side effects, which can vary in severity. Some common side effects include:

• Nausea and vomiting
• Diarrhea
• Tremors
• Increased thirst and urination
• Weight gain
• Cognitive impairment

Serious side effects may include:

• Kidney dysfunction
• Thyroid dysfunction
• Low blood sodium levels (hyponatremia)
• Lithium toxicity

Patients taking lithium should be closely monitored by their healthcare provider, with regular blood tests to assess lithium levels, kidney function, and thyroid function.

Contraindications

Lithium is contraindicated in patients with severe kidney impairment, severe heart disease, or low blood sodium levels. It should also be used with caution in pregnant and breastfeeding women, as lithium can cross the placenta and be excreted in breast milk.

Drug Interactions

Lithium may interact with several other medications, including:

• Diuretics
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Angiotensin-converting enzyme (ACE) inhibitors
• Antidepressants

These interactions may alter lithium levels in the body and increase the risk of side effects or reduce the drug's effectiveness. It is essential to inform the healthcare provider of all medications being taken while on lithium therapy.

External Links

• National Institute of Mental Health - Bipolar Disorder
• MedlinePlus - Lithium