Antidepressant Discontinuation Syndrome

Abstract

The Art of Prescribing is a question-and-answer forum that can help nurses maintain their knowledge of advances in prescribing, psychopharmacology, and implications for safe psychiatric care. Send your questions related to prescribing psychotropic medications to the Editor, Mary Paquette, at mary@artwindows.com. Question: One of my patients called several days after she abruptly stopped taking her SSRI antidepressant. She had been on 30 mg of paroxetine for several months and stopped because she felt better. Her chief complaints were dizziness, sleep disturbances, shakiness, and nervousness. What caused these symptoms? Are SSRIs and other novel antidepressants addictive? Deborah Antai-Otong responds: Antidepressants are not addictive; nonadherence or abrupt withdrawal, however, can produce uncomfortable and sometimes serious reactions. There is growing evidence that a sizeable number of patients who are nonadherent or who abruptly discontinue SSRIs and other novel and older antidepressants report somatic, mood, and psychomotor symptoms or discontinuation syndrome. Typical presentations of discontinuation syndrome include lightheadedness, dizziness, headaches, GI disturbances, diaphoresis, lethargy, vivid dreams, and flu-like symptoms (Coupland, Bell & Potokar, 1996; Fava & Rosenbaum, 1996). This syndrome is more evident in patients receiving short-acting agents, such as paroxetine (Paxil), fluvoxamine (Luvox), sertraline (Zoloft), and venlafaxine (Effexor), and less evident in patients receiving long-acting agents, such as fluoxetine (Prozac) with a longer half-life, nefazodone (Serzone), and citalopram (Celexa) (Antai-Otong, 2003; Coupland et al., 1996; Schatzberg et al., 1997). Signs and Symptoms As a rule, symptoms emerge within 24 to 72 hours of discontinuation and may persist from 1 to 2 weeks. A differential diagnosis is necessary to rule out other causes (Schatzberg et al., 1997). A rule of thumb concerning discontinuation syndromes is that the shorter the half-life of the antidepressant, the higher the incidence of the syndrome with abrupt withdrawal (Coupland et al., 1996). In essence, most factors that affect discontinuation syndromes include time on the drug (e.g., [greater than or equal to] 2 months), drug potency, and half-life. Drugs with a shorter half-life wash out of the brain before the brain adapts or stabilizes its receptors resulting in withdrawal symptoms. For example, compare the half-life of paroxetine (15-22 hours) with fluoxetine (1-3 days) and its active metabolite (7-15 days). Abrupt cessation of fluoxetine decreases brain levels slowly over several weeks (Schatzberg et al., 1997), whereas abrupt withdrawal of paroxetine rapidly decreases brain levels and does not allow for brain adaptation, hence the increased risk of discontinuation syndrome. The Discontinuation Consensus Panel (Schatzberg et al., 1997) describes major discontinuation symptoms as physical and psychological, and characterized by the following clusters: * Disequilibrium (e.g., dizziness [exacerbated by movement or postural changes], lightheadedness, vertigo, ataxia, headaches) * GI (e.g., nausea, vomiting, loose stools, dry mouth) * Flu-like symptoms (e.g., myalgia, fatigue/lethargy, shaking chills, rhinorrhea) * Sensory disturbance (e.g., paresthesia, sensations of electric shock, burning, tingling) * Sleep disturbances (e.g., vivid dreams, initial and middle insomnia) * Psychological (e.g., anxiety, agitation, mania, crying spells, cognitive disturbances, slowed thinking) Sometimes discontinuation symptoms are mistaken for worsening depression or even emergence of mania. It is imperative for nurses to distinguish discontinuation syndrome-mania from mania as a natural course of bipolar disorder (Ali & Milev, 2003). …