CENTRAL NEUROMODULATORS IN IRRITABLE BOWEL SYNDROME. WHY, HOW AND WHEN.

Abstract

Irritable bowel syndrome are responsive to treatments using central neuromodulators. Central neuromodulators work by enhancing the synaptic transmission of 5-hydroxytryptamine, noradrenalin and dopamine, achieving a slower regulation or desensitization of their postsynaptic receptors. Central neuromodulators act on receptors along the brain-gut axis, so they are useful in treating psychiatric comorbidities, modifying gut motility, improving central downregulation of visceral signals and enhancing neurogenesis in patients with IBS. Choosing a central neuromodulator for treating IBS should be according to the pharmacological properties and the predominant symptoms. The first-line treatment for pain management in IBS is using tricyclic antidepressants. An alternative for pain management is the serotonin and noradrenaline reuptake inhibitors. Selective serotonin reuptake inhibitors are useful when symptoms of anxiety and hypervigilance are dominant but are not helpful for treating abdominal pain. The predominant bowel habit is helpful when choosing a neuromodulator to treat IBS; SSRIs help constipation, not pain, but may cause diarrhea; TCAs help diarrhea but may cause constipation. A clinical response may occur in 6-8 weeks, but long-term treatment (usually 6-12 months) is required after the initial response to prevent relapse. Augmentation therapy may be beneficial when the therapeutic effect of the first agent is incomplete or associated with side effects. It is recommended to reduce the dose of the first agent and add a second complementary treatment. This may include an atypical antipsychotic or brain-gut behavioral treatment. When tapering central neuromodulators, the dose should be reduced slowly over 4 weeks but may take longer when discontinuation effects occur.