CNS or classic drugs for the treatment of pain in functional dyspepsia? A systematic review and meta-analysis of the literature

Recent evidence has suggested that pain in functional dyspepsia (FD) is associated with nervous system dysfunction; indicating that therapies aimed at nervous system modulation might be associated with pain relief in FD. To conduct a systematic review and meta-analysis to quantify the efficacy of drugs targeting the central nervous system (antidepressants and antianxiety agents - referred as "CNS drugs") and drugs targeting gastric modulation (antisecretory and prokinetic - referred as "classic drugs") for the treatment of pain in FD and, in an exploratory way, compare these 2 modalities of treatment. MEDLINE and reference lists were examined for relevant articles. We included prospective studies that evaluated the effects of either CNS drugs or classic drugs (subdivided in prokinetic and antisecretory drugs) on the symptoms of FD. Seven studies for CNS drugs and 11 studies for gastric drugs met our inclusion criteria. The analyses of these drugs showed that the 2 groups of drugs are associated with a significant reduction in dyspeptic symptoms. The pooled effect size (standardized mean difference between pre-treatment versus post-treatment means) from the random effects model was 1.25 (95% C.I., 0.83, 1.67) for CNS; 1.63 (95% C.I., 1.28, 1.97) for prokinetic, and 0.93 (95% C.I., 0.57, 1.29) for antisecretory drugs. The exploratory comparison between classes of drugs revealed no significant difference in dyspeptic symptoms reduction between CNS and prokinetic drugs; however CNS drugs were associated with a larger reduction in symptoms as compared with antisecretory drugs. The results show that both CNS and classic drugs are associated with a significant pain reduction in functional dyspepsia.