From the Guidelines
Selective Serotonin Reuptake Inhibitors (SSRIs), Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs), gabapentin, pregabalin, and benzodiazepines are commonly used to treat anxiety disorders, with SSRIs and SNRIs being the most effective and safe options.
Dosing Information
- SSRIs: The dosing of SSRIs varies by medication, but most can be taken once daily due to their long elimination half-lives 1. For example, fluoxetine has a long elimination half-life, while sertraline and fluvoxamine may require twice-daily dosing at low doses.
- SNRIs: Venlafaxine extended release, desvenlafaxine, and duloxetine have long elimination half-lives, allowing for single daily dosing, while venlafaxine immediate release may require twice- or thrice-daily dosing 1.
- Gabapentin and Pregabalin: There is limited information on the use of gabapentin and pregabalin for anxiety disorders in the provided evidence.
- Benzodiazepines: While benzodiazepines can be effective for anxiety, their use is generally recommended for short-term treatment due to the risk of dependence and withdrawal 1.
Key Considerations
- Slow up-titration is recommended for SSRIs to avoid unintentionally exceeding the optimal medication dose and to minimize the risk of adverse effects such as behavioral activation/agitation 1.
- Close monitoring is necessary, especially in the first months of treatment and following dosage adjustments, due to the risk of suicidal thinking and behavior, particularly in youths 1.
- Combination therapy should be approached with caution, as the risk of serotonin syndrome increases when serotonergic medications are combined 1.
From the Research
Appropriate Doses for Anxiety Disorders
- The appropriate doses of Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) for anxiety disorders are not explicitly stated, but higher doses of SSRIs within the therapeutic range are associated with greater treatment benefit, whereas higher doses of SNRIs are not 2.
- For pregabalin, doses of 600 mg or 450 mg/d are effective for treating generalized social anxiety disorder 3.
- For benzodiazepines, the dose is not explicitly stated, but they are effective in treating generalized anxiety disorder, with a greater effect size compared to SSRIs and SNRIs 4.
- A dose-response effect is evident for pregabalin, with significant improvement in both psychic and somatic anxiety factors at doses of 300-600 mg/d, and a plateau at a dose of 300 mg/d 5.
Comparison of Medications
- SSRIs and SNRIs are effective in treating anxiety disorders, with no significant differences in efficacy between pharmacological agents within each class or when comparing SSRIs to SNRIs 2.
- Pregabalin may be an effective therapeutic option for patients who cannot tolerate the adverse effects or who demonstrate a lack of efficacy with SSRIs or SNRIs 3.
- Benzodiazepines have a rapid onset of action, but can cause tolerance and dependence, while SSRIs have a delay of several weeks in onset of therapeutic effect and have the potential to exacerbate anxiety and panic early in the treatment course 6.
Efficacy of Medications
- The overall combined effect size for the efficacy of SSRIs, SNRIs, and benzodiazepines in the treatment of adults with generalized anxiety disorder is modest to moderate, with benzodiazepines demonstrating a greater effect size 4.
- Pregabalin is associated with significant improvement in both psychic and somatic anxiety factors, with a dose-response effect evident 5.