Bipolar disorder, formerly known as manic depression, is a mental health condition characterized by extreme mood swings. People with bipolar disorder alternate between episodes of mania (high energy and impulsiveness) and depression (extreme low energy and feelings of hopelessness). Medication is often used as part of treatment for bipolar disorder to help regulate moods and prevent or reduce the severity of episodes.
What is lithium?
Lithium is a mood stabilizing medication that has been used since the 1970s to treat bipolar disorder. It works by decreasing abnormal activity in the brain and helping regulate mood. Lithium helps prevent manic and hypomanic episodes and can also be used to treat acute mania. It may also reduce the frequency and severity of depressive episodes.
Lithium is available in regular and extended release oral formulations. Regular lithium must be taken 2-3 times per day, while extended release only needs to be taken once daily. Lithium takes 1-2 weeks to reach optimal blood levels. Blood levels must be monitored regularly to ensure therapeutic levels are maintained and to prevent toxicity.
How effective is lithium for treating bipolar disorder?
Lithium is considered a first-line mood stabilizer for bipolar disorder. It is one of the oldest and most well-researched medications used in bipolar treatment. Lithium has been shown to be effective for:
- Treating acute mania
- Preventing future manic and hypomanic episodes
- Preventing depressive episodes
- Reducing suicide risk
In clinical studies, lithium has outperformed placebo for the treatment of acute mania with response rates around 50%. It has also been shown to prolong the time between mood episodes in people with bipolar disorder.
One analysis looked at 6 studies involving over 300 patients. It found that lithium decreased the risk of relapse in bipolar disorder by 70% compared to placebo over a period of 1-2 years. The number needed to treat was 4, meaning 4 patients would need to be treated with lithium to prevent 1 relapse.
Lithium also appears to have anti-suicidal effects. One study found patients taking lithium had an 8.5 times lower risk of death by suicide compared to patients not taking lithium.
Benefits of lithium
- Effective for treating acute mania and long-term mood stabilization
- Reduces frequency and severity of mood episodes
- Prevents mania and depression relapse
- Lowers risk of suicide
- Inexpensive relative to other bipolar medications
Is lithium considered a first-line treatment?
Lithium is generally considered a first-line mood stabilizer for bipolar disorder. Treatment guidelines list lithium as one of the first medication options for:
- Acute manic and mixed episodes
- Maintenance treatment
The American Psychiatric Association, Canadian Network for Mood and Anxiety Treatments, British Association for Psychopharmacology, and World Federation of Societies for Biological Psychiatry all recommend lithium as a first-line maintenance treatment.
Lithium, along with valproate, is preferred over other maintenance medications like lamotrigine or olanzapine based on its superior efficacy in preventing relapse of mood episodes.
One analysis looked at over 40 studies involving thousands of patients with bipolar disorder. It found that lithium was more effective than placebo or other mood stabilizers in preventing all types of mood relapse. Lithium had lower rates of manic, hypomanic, mixed, and depressive relapse compared to placebo and other medications.
When is lithium used for bipolar disorder?
The main uses of lithium in bipolar disorder include:
Acute mania
Lithium can be used alone or in combination with an antipsychotic to treat a current manic or mixed episode.
Maintenance treatment
Lithium is commonly used as a long-term maintenance medication to prevent future episodes of mania or depression in bipolar disorder.
Unipolar depression
Lithium may sometimes be used as an add-on treatment for difficult to treat major depressive disorder.
Augmentation in depression
Lithium can also be added to an antidepressant to enhance its effects if the antidepressant alone is not fully effective for bipolar depression.
How does lithium compare to other bipolar medications?
Lithium is considered one of the most effective medications for bipolar disorder. Here is how it compares to some other commonly used bipolar drugs:
Anticonvulsants
Anticonvulsants like valproate (Depakote) and lamotrigine (Lamictal) are also used as mood stabilizers in bipolar disorder. Lithium is generally preferred over these options for long-term maintenance treatment because studies show it has lower rates of relapse.
Lamotrigine may be preferred over lithium for bipolar depression as some research shows it is more effective for this phase of illness. But for mania prevention, lithium remains the first-line.
Atypical antipsychotics
Atypical antipsychotics like olanzapine (Zyprexa), risperidone (Risperdal), and quetiapine (Seroquel) are commonly used in bipolar as add-on agents to lithium or valproate. Lithium and valproate seem to have better evidence than antipsychotics for maintenance treatment.
However, some analyses have found that the combination of lithium plus an antipsychotic may be more effective than lithium alone.
Antidepressants
Antidepressants are controversial in bipolar disorder due to the risk of inducing mania. Lithium is preferred over antidepressant monotherapy for bipolar depression. However, lithium can be safely combined with an antidepressant for a synergistic effect.
What are the potential side effects of lithium?
Lithium is generally well-tolerated when used at appropriate therapeutic levels. Potential side effects may include:
- Nausea, diarrhea, vomiting
- Tremor
- Increased thirst and urination
- Weight gain
- Hypothyroidism
- Cognitive dulling
- Skin rash
Toxicity can occur if blood levels become too high. Symptoms of lithium toxicity include:
- Nausea, vomiting, diarrhea
- Tremor
- Confusion
- Seizures
- Irregular heart rhythms
Lithium toxicity is a medical emergency requiring immediate treatment. Lithium levels must be monitored carefully through regular blood tests to avoid toxicity.
Who should not take lithium?
Lithium may not be suitable for people with certain medical conditions or taking certain medications. Lithium should be avoided in patients with:
- Significant kidney disease
- Significant heart disease
- Low sodium levels
- Pregnant women
- Older adults due to increased side effect risk
Lithium also interacts with certain medications including:
- Diuretics
- ACE inhibitors
- NSAIDs
- Some antibiotics
These drugs can increase lithium levels so close monitoring is required if they are used together.
Lithium monitoring
Frequent monitoring and blood tests are required when taking lithium. This includes:
- Baseline kidney and thyroid function tests
- Lithium blood levels every 1-3 months
- Monitoring kidney function every 2-3 months
- Monitoring thyroid hormones every 6-12 months
- Monitoring for signs of toxicity
Target lithium levels for acute treatment are generally 0.8-1.2 mEq/L. For maintenance, levels of 0.6-0.8 mEq/L are often used.
DOSAGE FORMS AND STRENGTHS
Lithium is available in the following dosage forms and strengths:
| Form | Strengths |
|---|---|
| Regular tablets | 300 mg |
| Sustained-release tablets | 300 mg, 450 mg |
| Capsules | 150 mg, 300 mg, 600 mg |
| Liquid | 300 mg/5mL |
The typical starting dosage of lithium for bipolar disorder is 300 mg taken 2-3 times per day. The dose is then adjusted based on blood levels and clinical response.
Conclusion
In summary, lithium remains first-line for treating acute mania and preventing relapse of mood episodes in bipolar disorder. It has the most extensive evidence base supporting its efficacy compared to other medications used in bipolar treatment. Lithium is underutilized in part due to concerns about side effects and toxicity monitoring. However, with proper precautions, lithium can be safely administered. For patients who tolerate it well, lithium is often the maintenance treatment of choice for stabilizing moods long-term.