Showing papers by "John Potokar published in 2009"

Antidepressant-induced jitteriness/anxiety syndrome: systematic review

Abstract: Background Early worsening of anxiety, agitation and irritability are thought to be common among people commencing antidepressants, especially for anxiety disorders. This phenomenon, which may be termed jitteriness/anxiety syndrome, is cited as an explanation for early treatment failure and caution in using selective serotonin reuptake inhibitors (SSRIs). However, we believe that it is inconsistently defined and that robust evidence to support the phenomenon is lacking. Aims To review systematically all evidence relating to jitteriness/anxiety syndrome to identify: constituent symptoms; medications implicated; disorders in which it was reported; incidence; time course; management strategies; relationship of this syndrome to therapeutic response; distinction between syndrome and akathisia; relationship between syndrome and suicide; and genetic predispositions. Method A systematic search identified articles and these were included in the review if they addressed one of the above aspects of jitteriness/anxiety syndrome. Results Of 245 articles identified, 107 articles were included for review. No validated rating scales for jitteriness/anxiety syndrome were identified. There was no robust evidence that the incidence differed between SSRIs and tricyclic antidepressants, or that there was a higher incidence in anxiety disorders. Published incidence rates varied widely from 4 to 65% of people commencing antidepressant treatment. Common treatment strategies for this syndrome included a slower titration of antidepressant and the addition of benzodiazepines. Conclusive evidence for the efficacy of these strategies is lacking. There was conflicting and inconclusive evidence as to whether the emergence of this syndrome had a predictive value on the response to treatment. It appears to be a separate syndrome from akathisia, but evidence for this assertion was limited. The effect of jitteriness/anxiety syndrome on suicide rates has not been evaluated. Three studies examined genetic variations and side-effects from treatment, but none was specifically designed to assess jitteriness/anxiety syndrome. Conclusions Jitteriness/anxiety syndrome remains poorly characterised. Despite this, clinicians' perception of this syndrome influences prescribing and it is cited to support postulated mechanisms of drug action. We recommend systematised evaluation of side-effects at earlier time points in antidepressant trials to further elucidate this clinically important syndrome.

Women with diarrhoea-predominant irritable bowel syndrome show an increased pressure response to 35% carbon dioxide stress challenge.

Abstract: The responses to inhalation of 35% carbon dioxide (CO(2)) as a stressor were compared in female irritable bowel syndrome (IBS) patients and healthy controls to assess potential differences in cardiovascular, neuroendocrine and behavioural responses to stress. A total of 22 women (12 patients with ROME II defined diarrhoea-predominant IBS and 10 aged-matched controls) were challenged with a single vital capacity breath of 35% CO(2) (with 65% oxygen). Beat-to-beat blood pressure and heart rate were recorded prior to, during and after the inhalation. Serum cortisol concentration and behavioural ratings were measured pre- and post-inhalation. A typical pattern of responses to CO(2) was observed, characterised by a reduction in heart rate and increases in serum cortisol and anxiogenic symptoms; however, these responses did not differ between groups. Both groups also demonstrated an increase in systolic blood pressure; however, this response was significantly enhanced in IBS patients compared to healthy controls (P < 0.05). These findings demonstrate that females with diarrhoea-predominant IBS have an exaggerated pressor response to 35% CO(2) stress challenge, suggesting a more stress-responsive sympathetic nervous system.