52 - Rate of tapering

Rate of tapering

378 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 3 Stopping antidepressants Up to 50% of patients will experience withdrawal symptoms on reducing or stopping an antidepressant,1,2 but symptoms are less common in shorter-­term users.3 For a small proportion of patients, withdrawal symptoms will be severe1,3 or will last for months or years.1,4 Post-­acute or protracted withdrawal syndrome (PAWS) is the term used for long-­lasting symptoms that last for years and may involve myriad, sometimes debilitating, symptoms.2,5 Alterations to serotonin and hormonal systems after stopping antidepressants are seen in patients and animals and these changes may persist for months and years after long-­term antidepressant exposure.2 There are a number of characteristics of antidepressant use that influence the likelihood of withdrawal effects. Patients who have been on antidepressants for longer periods and at higher doses are more likely to have withdrawal effects.2 Antidepressants with short half-­lives and anticholinergic or noradrenergic effects tend to be associated with more severe withdrawal. Venlafaxine, desvenlafaxine, duloxetine and paroxetine are the most often implicated.2,6 Patients who stop abruptly or rapidly have more withdrawal effects.7 There are likely to be a range of individual physiological (and psychological) differences, as yet poorly understood, which also determine withdrawal severity.2 Withdrawal symptoms include both physical and psychological symptoms, because antidepressants affect a wide variety of bodily systems.7 Physical symptoms include headache, dizziness, nausea, depersonalisation/derealisation, muscle cramps, brain ‘zaps’ and akathisia. Psychological symptoms include low mood, anxiety, panic attacks, tearfulness, obsessive thinking, impaired concentration and suicidality. Psychological symptoms can easily be mistaken for a relapse of an underlying condition. Timing of onset, symptoms distinct in nature or severity from the underlying condition and response to reinstatement of the drug can help to distinguish withdrawal effects from relapse.8 Further details are provided in the Maudsley Deprescribing Guidelines: Antidepressants, Benzodiazepines, Gabapentinoids and Z-­drugs.9 Rate of tapering There is good evidence that tapering slowly can reduce the likelihood of withdrawal symptoms and also of relapse.7,10,11 Meta-­regression of discontinuation studies found a highly significant lowering of relapse rate with longer tapering.10 In fact, there was no difference in relapse rate between maintenance treatment and tapering over 6 months.10 While tapering over several months reduces the risk of withdrawal symptoms,7 some patients may take years to withdraw. Clinical experience suggests that long-­term users of antidepressants generally take between 3 months and 3 years to withdraw in a tolerable manner.12 In one study, 40% of patients taking antidepressants for more than 1–2 years were able to taper off successfully in approximately 4 months, suggesting that 60% will need longer than this.13