What is the efficacy of using fluoxetine (selective serotonin reuptake inhibitor) with a mood stabilizer for treating Bipolar II disorder?

From the Guidelines

Fluoxetine should be used in combination with a mood stabilizer, such as lithium or valproate, for the treatment of moderate or severe depressive episodes of bipolar disorder, as recommended by the WHO guidelines 1. When treating Bipolar II disorder, it is crucial to consider the efficacy and safety of using fluoxetine, a selective serotonin reuptake inhibitor (SSRI), in conjunction with a mood stabilizer. The primary goal is to alleviate depressive symptoms while minimizing the risk of triggering mania or rapid cycling. Key considerations for this treatment approach include:

• Selecting a suitable mood stabilizer, such as lithium or valproate, to pair with fluoxetine, as these medications have been shown to be effective in maintaining mood stability 1.
• Initiating fluoxetine at a typical dose of 20mg daily, with gradual increases as needed, to achieve optimal therapeutic effects while minimizing side effects.
• Close monitoring of patients, particularly during the initial months of treatment, to promptly identify potential signs of mood elevation, such as increased irritability, decreased sleep, or racing thoughts.
• Being aware of common side effects associated with fluoxetine, including nausea, headache, insomnia, or sexual dysfunction, and adjusting the treatment plan accordingly. The combination of fluoxetine and a mood stabilizer is particularly beneficial when depressive symptoms are predominant in bipolar II disorder, as it allows for targeted treatment of depression while protecting against mood elevation 1.

From the Research

Efficacy of Fluoxetine with a Mood Stabilizer for Treating Bipolar II Disorder

• The efficacy of using fluoxetine (a selective serotonin reuptake inhibitor) with a mood stabilizer for treating Bipolar II disorder is supported by several studies 2, 3, 4.
• A study published in 2004 found that fluoxetine monotherapy may be a safe and effective initial treatment for Bipolar II major depressive episode, with a low manic switch rate 2.
• Another study published in 2005 found that fluoxetine monotherapy may be effective as an initial treatment for Bipolar II and Bipolar NOS major depression, with a low manic switch rate 3.
• A study published in 1998 found that fluoxetine may be a safe and effective antidepressant monotherapy for the short-term treatment of Bipolar II depression, with a relatively low manic switch rate 4.

Combination Therapy with Olanzapine and Fluoxetine

• Combination therapy with olanzapine and fluoxetine has been found to be effective in the treatment of patients with acute bipolar depression 5, 6.
• The combination of olanzapine and fluoxetine improves depressive symptoms and symptom severity in patients with acute bipolar depression, with an efficacy greater than that of olanzapine alone or lamotrigine 5, 6.
• The combination is generally well tolerated, although it may be associated with weight gain and potential elevations in glucose, lipid, and prolactin levels 5, 6.
• The combination does not increase the risk of treatment-emergent mania 5, 6.

Manic Switch Rate

• The manic switch rate associated with fluoxetine monotherapy in Bipolar II disorder has been found to be low in several studies 2, 3, 4.
• A study published in 2004 found that only three patients (7.3%) had symptoms suggestive of hypomania during fluoxetine monotherapy 2.
• A study published in 2005 found that no hypomanic switch episodes were observed during fluoxetine monotherapy 3.
• A study published in 1998 found that three Bipolar II patients (3.8%) had a "manic switch" during short-term fluoxetine therapy, compared to no matched unipolar patients 4.