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Tips to manage and prevent discontinuation syndromes Informed tapering can protect patients when you stop a medication.

Vol. 4, No. 9 / September 2005 Sriram Ramaswamy, MD Instructor, department of psychiatry, Creighton University, Omaha, NE Shruti Malik, MBBS, MHSA Foreign medical graduate Vijay Dewan, MD Assistant professor, department of psychiatry, University of Nebraska Medical Center, Omaha, NE

Abruptly stopping common psychotropics—particularly antidepressants, benzodiazepines, or atypical antipsychotics—can trigger a discontinuation syndrome, with: • rebound or relapse of original symptoms • uncomfortable new physical and psychological symptoms • physiologic withdrawal at times. Up to 30% of patients who stop taking SSRIs develop discontinuation symptoms. 4 Six symptom clusters—disequilibrium, sensory symptoms, general somatic symptoms, sleep disturbance, GI symptoms, and affective symptoms—characterize the SSRI discontinuation syndrome (Table 2).5 The four most common symptoms—in decreasing order of frequency—are dizziness, nausea, lethargy, and headache.6 Ataxia, sensory abnormalities, and possibly aggressive and impulsive behavior differentiate this discontinuation syndrome from that of the TCAs. Discontinuation syndrome risk among SSRIs is highest for paroxetine, intermediate for sertraline and fluvoxamine, and lowest for fluoxetine.4 Citalopram may cause a mild and transient discontinuation syndrome.8 Citalopram’s long elimination half-life (30 to 35 hours) and fewer and much less-potent active metabolites9 may explain its relatively low risk of discontinuation symptoms. Discontinuation reactions have been reported to occur 100 times more frequently with paroxetine than with fluoxetine.10 Fluoxetine’s lower rate could be explained by its 2- to 3-day half-life, compared with half-lives of 33 hours or less for paroxetine, sertraline, citalopram, and fluvoxamine. A longer half-life might protect against a discontinuation syndrome. Atypical Antipsychotic Discontinuation Syndromes Except for aripiprazole—which is a partial dopamine receptor agonist—most atypical antipsychotics are serotonin-dopamine antagonists. Discontinuation syndrome occurs most commonly with clozapine. Clozapine. Abruptly stopping clozapine can exacerbate psychosis or cause delirium, agitation, confusion, and diaphoresis. Less-common symptoms may include extrapyramidal effects, nausea, diarrhea, headache, or restlessness.14 Clozapine is a weak dopamine D2 antagonist and a potent antagonist at the serotonin 5HT2, alpha adrenergic, histaminergic, and anticholinergic receptors. Thus, rebound from cholinergic, serotonin, dopamine and/or adrenergic receptor supersensitivity is thought to cause its discontinuation syndrome.15 Other atypicals. Case reports describe tics and withdrawal-emergent dyskinesia with risperidone16 and supersensitivity psychosis and a cholinergic/serotonergic syndrome with olanzapine.17,18 Anecdotal reports suggest that abruptly discontinuing quetiapine can cause nausea, emesis, lightheadedness, diaphoresis, orthostasis, tachycardia, and nervousness.19,20 Although discontinuation syndromes have not been reported with ziprasidone or aripiprazole, tapering any atypical antipsychotic during discontinuation is prudent.

This post was edited on 9/24/14 at 2:07 pm