Pharmacotherapy of Anxiety Disorders in Adults

This guideline provides Canadian pharmacists with a structured approach to managing anxiety disorders, emphasizing both pharmacological and non-pharmacological options. Treatment strategies may vary depending on patient needs, available psychological services, and individual preferences. In older adults, non-pharmacological approaches, such as Cognitive Behavioral Therapy (CBT), are generally preferred as a first-line treatment for anxiety. However, treatment choices should consider factors such as symptom severity, comorbid conditions (e.g., depression, bipolar disorder, chronic pain), contraindications, previous response to therapies, and potential side effects.

General Treatment Considerations

• Combination Therapy: Pharmacotherapy and non-pharmacological therapy, like CBT, can be combined for enhanced outcomes.

• Address Contributing Factors: Identify and manage medications or conditions that may contribute to anxiety, such as benzodiazepine withdrawal, substance abuse, or stimulant use.

• First- and Second-Line Medications: Treatment options for different types of anxiety disorders are categorized by first- and second-line choices, based on evidence of effectiveness and side effect profiles.

Pharmacotherapy Options

1. SSRIs (Selective Serotonin Reuptake Inhibitors) and SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors):

• Examples: SSRIs such as escitalopram, sertraline, paroxetine; SNRIs like venlafaxine and duloxetine.

• Mechanism: These medications increase serotonin (and in the case of SNRIs, norepinephrine) levels in the brain, which helps regulate mood and reduce anxiety.

• First-Line Role: SSRIs and SNRIs are preferred as first-line options due to their favorable balance between efficacy and safety.

• Dosing: Start at a low dose and increase gradually, especially when used off-label, as appropriate dosing in anxiety may vary.

2. Benzodiazepines:

• Examples: Lorazepam, clonazepam, alprazolam.

• Role and Limitations: Benzodiazepines are used primarily for short-term relief due to risks of dependence, withdrawal, and side effects like sedation and cognitive impairment. They are generally a second-line choice for acute anxiety management or specific cases where immediate symptom control is needed.

• Caution: Avoid long-term use, especially in older adults, due to higher risks of falls and cognitive impairment.

3. Monitoring and Assessment

• Use validated tools such as GAD-7 (Generalized Anxiety Disorder-7), PAS (Panic and Agoraphobia Scale), SPS/SIAS (Social Phobia Scale/Social Interaction Anxiety Scale), or OCI-R (Obsessive-Compulsive Inventory-Revised) to track treatment response.

• Treatment Duration: For patients who respond to treatment, continue therapy for at least 6–12 months to reduce the risk of relapse.

Treatment Adjustments for Inadequate Response

• If the initial treatment yields an inadequate response, options include:

• Adding or Switching Psychological Therapy: If CBT or another psychological intervention was not part of the initial treatment, consider adding it.

• Adjusting Medication: Increase the dose if tolerable, add another medication, or switch to a different class based on the patient’s response and side effect profile.

Discontinuing Medication

• When discontinuing a medication, taper it slowly over weeks to months to minimize withdrawal symptoms and prevent relapse. Benzodiazepines, SSRIs, and SNRIs, in particular, should be tapered gradually under close monitoring.