Lithium

Bipolar Disorder

Lithium is primarily used to treat manic episodes in individuals with bipolar disorder, which was formerly known as manic-depressive illness. A manic episode is characterized by an abnormally excited, frenzied, or irritable mood. Symptoms that lithium helps manage during these episodes include:

• Racing thoughts and rapid talking
• Increased energy or physical activity
• Reduced need for sleep
• Inflated self-esteem or grandiosity
• Poor judgment or impulsivity

Maintenance Therapy

Beyond treating active symptoms, lithium is used as a long-term maintenance treatment. In this role, it helps to:

• Prevent the recurrence of future manic episodes.
• Reduce the intensity and frequency of mood swings.
• Help stabilize the patient's overall mood over time.

It is often prescribed for patients with a history of mania to help them maintain a more balanced emotional state and prevent relapses.

Mechanism of Action

Lithium belongs to a class of medications known as antimanic agents. Although it has been used for decades, the exact way lithium works to stabilize mood is not fully understood by medical researchers.

It is believed that lithium helps balance the brain's chemistry through several processes:

• Regulating Neurotransmitters: Lithium may influence the activity of chemical messengers in the brain, such as serotonin, dopamine, and norepinephrine, which are responsible for regulating mood and behavior.
• Altering Cell Signaling: The medication is thought to change the way sodium is transported through nerve and muscle cells. This helps manage how the nervous system processes and sends signals.
• Reducing Brain Activity: Lithium helps decrease abnormal or excessive electrical activity in the brain that can lead to the extreme high energy, agitation, and impulsivity seen during manic episodes.

By acting on these pathways, lithium helps reduce the intensity and frequency of mania and can help prevent future mood swings in people with bipolar disorder.

Common Side Effects

Some side effects may occur as your body adjusts to the medication. Common side effects include:

• Nausea, diarrhea, or mild stomach pain
• Increased thirst and more frequent urination
• Fine hand tremors
• Weight gain
• Dizziness or drowsiness
• Muscle weakness
• Dry mouth
• Thinning hair or skin rashes like acne

Serious Side Effects

Seek medical attention immediately if you experience any of the following:

• Severe nausea, vomiting, or persistent diarrhea
• Severe tremors or muscle twitching
• Slurred speech or blurred vision
• Confusion, hallucinations, or extreme restlessness
• Seizures
• Fainting or a fast, slow, or irregular heartbeat
• Swelling of the feet or lower legs
• Excessive sleepiness or lethargy

Boxed Warning: Lithium Toxicity

Lithium toxicity is closely related to the concentration of the drug in the blood and can occur at doses very close to therapeutic levels. Regular blood monitoring is essential to ensure safety. Early signs of toxicity include diarrhea, vomiting, tremors, muscle weakness, and a lack of coordination.

Kidney and Thyroid Health

Because the kidneys remove lithium from the body, individuals with kidney disease are at a higher risk for toxicity. Chronic lithium use may also lead to changes in kidney function. Additionally, lithium can cause thyroid issues, such as goiter or hypothyroidism, and may affect parathyroid function, leading to high calcium levels.

Fluid and Salt Balance

Maintaining a consistent intake of salt and water is necessary while taking lithium. Dehydration, heavy sweating, or a low-sodium diet can cause lithium to build up in the body, increasing the risk of toxicity. Caution is needed during illnesses that cause fever, vomiting, or diarrhea.

Neurological and Heart Risks

An encephalopathic syndrome, characterized by weakness, fever, and confusion, has been reported in patients taking lithium alongside certain antipsychotic medications. Lithium should also be used with caution in patients with cardiovascular disease, as it may affect heart rhythms or unmask underlying conditions like Brugada syndrome.

Pregnancy and Breastfeeding

• Pregnancy: Lithium may cause fetal harm, particularly heart defects like Ebstein's anomaly, if used during pregnancy.
• Breastfeeding: Lithium is excreted in human milk and may cause side effects in nursing infants; breastfeeding is generally not recommended during treatment.

Pregnancy

Lithium can cause fetal harm when taken during pregnancy. Research indicates that exposure, particularly during the first trimester, is associated with an increased risk of heart malformations, such as Ebstein's anomaly. If you become pregnant while taking this medication, it is important to notify your healthcare provider immediately to discuss the risks and benefits of continuing treatment.

In some cases, healthcare providers may recommend specialized ultrasounds to monitor the baby's heart development if lithium treatment is maintained during pregnancy. The decision to use lithium involves weighing the potential risks to the fetus against the risks of untreated mood symptoms for the parent.

Breastfeeding

Lithium passes into breast milk and can affect a nursing infant. Because of the potential for serious side effects, healthcare providers often advise caution. If breastfeeding occurs while taking lithium, the infant should be closely monitored for signs of toxicity, which may include:

• Extreme drowsiness
• Poor muscle tone or floppiness
• Feeding difficulties
• Changes in skin color

A healthcare provider may recommend regular blood tests for the nursing infant to check lithium levels and kidney function. Decisions regarding breastfeeding should be made in consultation with a medical professional, considering the health needs of both the parent and the child.

Available Forms

Lithium is primarily administered orally and comes in the following formulations:

• Lithium Carbonate Capsules: Standard immediate-release capsules.
• Lithium Carbonate Tablets: Standard immediate-release tablets.
• Lithium Carbonate Extended-Release Tablets: These are designed to release the medication slowly into the bloodstream over time.
• Lithium Citrate Oral Solution: A liquid form of the medication often used for patients who have difficulty swallowing pills.

FDA Approval and Indications

Lithium is approved by the U.S. Food and Drug Administration (FDA) for the treatment of manic episodes associated with bipolar disorder. It is also indicated as a maintenance treatment for patients with a history of mania to help prevent or reduce the intensity of future episodes.

Boxed Warning

The FDA has issued a boxed warning for lithium regarding the risk of lithium toxicity. Toxicity is closely related to the levels of lithium in the blood and can occur at doses very close to those required for effective treatment. Because of this narrow therapeutic range, the FDA requires that facilities for prompt and accurate serum lithium level testing be available before and during treatment.

Regulatory Precautions and Monitoring

In addition to blood level monitoring, regulatory guidelines emphasize the importance of monitoring kidney and thyroid function, as lithium can affect these organs over time. Lithium is also classified as a medication that carries risks during pregnancy, particularly in the first trimester, and is generally avoided unless the clinical benefits outweigh the potential risks to the fetus.

Stopping lithium treatment suddenly is generally not recommended because it significantly increases the risk of a relapse. When the medication is stopped abruptly, symptoms of mania or depression may return quickly and may be more severe than before.

To safely discontinue lithium, healthcare providers usually suggest the following:

• Gradual Tapering: Your doctor will likely create a schedule to slowly reduce your dose over a period of weeks or months. This gradual approach helps the brain adjust and reduces the likelihood of symptoms returning.
• Medical Supervision: Never attempt to stop or change your lithium dosage on your own. Always consult your healthcare provider before making any changes to your treatment plan.
• Monitoring: During the tapering process, it is important to stay in close contact with your medical team to monitor for any signs of mood changes or recurring symptoms.