Studies of b-blockers as SAD therapy have reported mixed results. Standing doses, ie, regular daily doses, of b-blockers for generalized SAD have performed poorly in clinical trials.39,46 These controlled trials have involved patients with generalized as well as circumscribed SAD. Results suggest that b-blockers are not effective in generalized SAD, and samples of patients with the nongeneralized subtype have been too small for meaningful analysis.42
b-Blockers have minimal adverse effects but should be avoided in patients with asthma, diabetes, and certain heart diseases. To minimize the risk of long-term psychological dependence, patients are encouraged to use the medication intermittently until their confidence in performance situations is restored. Thus, except for use in specific social performance situations, b-blockers are not recommended as a treatment for SAD.
Benzodiazepines
Benzodiazepines are the fastest-acting and perhaps the best-tolerated agents for the acute treatment of SAD. There is evidence that supports the use of benzodiazepines in SAD patients who are resistant to or unable to tolerate SSRIs.47 Controlled studies of alprazolam and clonazepam have reported acute treatment improvement rates ranging from 40% to 80%.15,48 While the improvement rates are impressive, benzodiazepines also have significant drawbacks. Patients often struggle to taper or discontinue benzodiazepines because of symptomatic worsening and acute relapse.15
Many clinicians use benzodiazepines in combination with an SSRI when starting treatment with the goal of discontinuing the benzodiazepine once the response to the SSRI is manifested. While this appears to be a reasonable practical approach, a small, 10-week randomized controlled trial of open-label paroxetine given in combination with clonazepam or placebo for SAD showed no significant differences between the 2 groups early or later in treatment.49
Benzodiazepines must also be cautiously used in patients who have a history of substance abuse. When benzodiazepines are used as needed for circumscribed SAD, sedation and psychological dependence can be a problem. In general, benzodiazepines are best reserved for patients at low risk for substance abuse in whom first-line treatments have failed. Benzodiazepines can also be useful for initial severe symptom relief in conjunction with an antidepressant, psychotherapy, or both.
Other agents
Two anticonvulsants, gabapentin and pregabalin, have demonstrated moderate effectiveness for generalized SAD. One randomized controlled trial of 600 mg/d of pregabalin in patients with SAD demonstrated efficacy.50 In another randomized controlled trial, gabapentin led to significant reductions in social anxiety after 14 weeks.51
Results of trials of the efficacy of buspirone as monotherapy for SAD have been mixed. This drug was found to be modestly effective in 2 open trials.52,53 In a subsequent double-blind, placebo-controlled study of patients with SAD, buspirone was found to be no different from placebo.54
However, buspirone may be useful in augmenting a partial response to an SSRI. The results of an 8-week study of 10 patients with SAD who were partially responsive to an SSRI suggest that the addition of buspirone to an SSRI as an augmentation strategy may be useful in enhancing treatment response.55
The tricyclic antidepressants have not been studied extensively in clinical trials of patients with SAD, but some case reports suggest that they may be effective. Findings from a large open-label study with clomipramine indicate that this agent may be effective for patients who have SAD. Another open trial of imipramine indicated a lack of efficacy.56,57
Agents such as bupropion, mirtazapine, nefazodone, olanzapine, and clonidine have not been investigated outside of case reports and clinical anecdotes.57
