To the Editor: We report a case of a possible withdrawal reaction following the discontinuation of nefazodone.

The possibility of a withdrawal reaction occurring after the discontinuation of selective serotonin reuptake inhibitors (SSRIs) and venlafaxine has previously been documented (1). Withdrawal symptoms typically occur 24 to 72 hours after SSRI discontinuation and can include sensory disturbances (e.g., parasthesia, sensations of electric shock), gastrointestinal complaints, dizziness, flu-like symptoms, and sleep disturbances (2). The incidence of withdrawal symptoms may be inversely related to the SSRI’s half-life, with fluoxetine having the lowest risk of a withdrawal reaction and paroxetine and fluvoxamine having the highest (1). However, symptom appearance could also be delayed in long half-life drugs, leading to underreporting for these agents.

The electric shock-like symptoms, dizziness, and nausea reported by Mr. A upon abrupt nefazodone discontinuation appear consistent with those reported by others to be typical of SSRI withdrawal. Nefazodone, like other SSRIs, is an inhibitor of serotonin reuptake. It is also an inhibitor of norepinephrine reuptake, a potent serotonin antagonist, and an α₁-adrenergic receptor antagonist (3). Because nefazodone has SSRI-like properties and a short half-life, it could possibly cause an SSRI-like withdrawal syndrome upon abrupt discontinuation.