Fluvoxamine. An updated review of its use in the management of adults with anxiety disorders.

UNLABELLED

Fluvoxamine is a potent and selective serotonin reuptake inhibitor (SSRI) that has little or no effect on other monoamine reuptake mechanisms. Relative to other SSRIs, fluvoxamine is a weak inhibitor of cytochrome P450 (CYP) 2D6, a moderate inhibitor of CYP2C19 and CYP3A4 and a potent inhibitor of CYP1A2. In randomised, double-blind trials. fluvoxamine 100 to 300 mg/day for 6 to 10 weeks significantly reduced symptoms of obsessive-compulsive disorder (OCD) compared with placebo. Response rates of 38 to 52% have been reported with fluvoxamine, compared with response rates of 0 to 18% with placebo. In patients with OCD, fluvoxamine had similar efficacy to that of clomipramine and, in smaller trials, the SSRIs paroxetine and citalopram and was significantly more effective than desipramine. Maintenance therapy with fluvoxamine may reduce the likelihood of relapses in up to 67% of patients with OCD. Fluvoxamine < or = 300 mg/day for 6 to 8 weeks was as effective as imipramine in patients with panic disorder, and significantly more effective than placebo. In addition, treatment with fluvoxamine < or = 300 mg/day for > or = 8 weeks improved symptoms of social phobia (social anxiety disorder), post-traumatic stress disorder (PTSD), pathological gambling, compulsive buying, trichotillomania, kleptomania, body dysmorphic disorder, eating disorders and autistic disorder. Large trials comparing the efficacy of fluvoxamine and other SSRIs in patients with anxiety disorders are warranted. Fluvoxamine is generally well tolerated; in postmarketing studies, nausea was the only adverse event occurring in >10% of patients with less commonly reported events including somnolence, asthenia, headache, dry mouth and insomnia. Fluvoxamine is associated with a low risk of suicidal behaviour, sexual dysfunction and withdrawal syndrome. Fewer anticholinergic or cardiovascular events are associated with fluvoxamine than tricyclic antidepressants. Although comparative data are lacking, the tolerability profile of fluvoxamine appears to be broadly similar to those of other SSRIs.

CONCLUSION

Fluvoxamine has demonstrated short term efficacy in the treatment of OCD, panic disorder, social phobia, PTSD and in a range of obsessive-compulsive spectrum disorders. The drug is as effective as clomipramine in patients with OCD but appears to have a better tolerability profile. On the basis of current treatment guidelines, fluvoxamine, like other SSRIs, is recommended as first-line treatment for a number of anxiety disorders. It appears to offer some pharmacokinetic advantages and a different drug interaction profile to the other SSRIs with a broadly similar spectrum of adverse events. However, direct comparisons are required to assess the relative efficacy and tolerability of the different agents of this drug class.