Rivastigmine for treatment-refractory posttraumatic stress disorder: a systematic review

We conducted a systematic review evaluating the efficacy of rivastigmine augmentation for treatment-refractory posttraumatic stress disorder (PTSD). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. The databases Ovid MEDLINE, PubMed, CINAHL, and EMBASE were searched using key words: 'rivastigmine' OR 'Exelon' OR 'rivastigmine augmentation' OR 'Exelon augmentation' AND 'posttraumatic stress disorder*' OR 'post-traumatic stress disorder*' OR 'PTSD' OR 'combat disorder*' OR 'post-traumatic symptoms'. The asterisk specified plural forms of the relevant word. Four papers were identified, comprising one double-blind randomised controlled trial, one non-controlled open trial, one case series (presenting three case studies), and one paper with two case studies. The randomised controlled trial found no statistically significant difference in efficacy, using the PTSD CheckList-Military Version as the relevant outcomes measure, between the active add-on rivastigmine interventions and placebo or treatment as usual. The open trial, although reporting relatively positive outcomes, had a weak study design and lacked reporting of key information, including participant sex and age and pre-rivastigmine PTSD measures. The assessment of efficacy was based on participants' reporting of subjective benefits, and clinician-rating using a Clinical Global Impression, rather than established PTSD assessments scales. Although the five case studies reported improvement in PTSD symptoms, there were confounding factors and limitations in clinical and demographic data, warranting caution regarding attributed benefits. There is a lack of methodologically robust evidence supporting the efficacy of add-on rivastigmine for the treatment of refractory PTSD. Additional research may help in further evaluating its possible clinical efficacy.