http://www.medscape.com/viewarticle/590815

Additional Agents Implicated in SSRI-Related Risk for Serotonin Syndrome

On February 24, the FDA approved class labeling changes for fluvoxamine maleate tablets and extended-release capsules (Luvox and Luvox CR, Jazz Pharmaceuticals) to provide updated information regarding drug interactions that increase the risk for serotonin-related adverse events in patients receiving treatment with selective serotonin reuptake inhibitors (SSRIs) such as fluvoxamine. This information also applies to selective serotonin-norepinephrine reuptake inhibitors.

The agency previously warned of the risk for potentially life-threatening serotonin syndrome in patients receiving 5-hydroxytryptamine receptor agonists (triptans) in conjunction with SSRIs.

An expanded section of the monograph now warns that serotonin syndrome or neuroleptic malignant syndrome (NMS)-like reactions can occur with use of SSRIs alone but are more likely with concomitant use of serotonergic drugs (including triptans), agents that impair serotonin metabolism (including monoamine oxidase inhibitors [MAOIs]), or antipsychotics and other dopamine antagonists.

Symptoms of serotonin syndrome may include mental status changes (eg, agitation, hallucinations, and coma); autonomic instability (eg, tachycardia, labile blood pressure, and hyperthermia); neuromuscular aberrations (eg, hyperreflexia and incoordination); and/or gastrointestinal symptoms (eg, nausea, vomiting, and diarrhea). Severe cases can resemble NMS, which includes hyperthermia, muscle rigidity, autonomic instability with possible rapid fluctuation of vital signs, and mental status changes. Patients should be monitored for the emergence of serotonin syndrome or NMS-like signs and symptoms.

Clinicians are reminded that concomitant treatment of depression with MAOIs and SSRIs is contraindicated. SSRI-treated patients receiving triptans should be followed up closely, particularly during initiation of therapy, dose increases, or the addition of another serotonergic drug.

Concomitant use of SSRIs with serotonin precursors (eg, tryptophan) is not recommended. Treatment with SSRIs and any concomitant serotonergic or antidopaminergic agents, including antipsychotics, should be discontinued immediately in patients who develop symptoms of serotonin syndrome.

Fluvoxamine tablets and controlled-release capsules are indicated for the treatment of obsessive-compulsive disorder; the capsules can also be used to treat social anxiety disorder.