Gastric Emptying Is Delayed in FD

The pathophysiology of functional dyspepsia (FD), a clinical syndromedefined by chronic or recurrent upper abdominal pain/discomfortof unknown origin, is poorly understood. This lack of understandinghas hindered efforts to develop effective treatments.

In a review article published in the August 2004 issue ofCurrent Treatment Options in Gastroenterology, VincenzoStanghellini, MD, and colleagues reported on drugs that targetupper gut dysmotility and sensory dysfunction, which are thoughtto be involved in the pathophysiology of FD. The drugs and drugclasses discussed included antidopaminergics (eg, metoclopramide,domperidone, levosulpiride), erythromycin and relatedderivatives (motilides), κ-opioid receptor agonists, antidepressants(eg, tricyclic agents, selective serotonin [5-hydroxytryptamine;5-HT] reuptake inhibitors), and 5-HT type 4 (5-HT4) receptoragonists (eg, tegaserod).

The authors noted that, because antidopaminergic agentsenhance gastric motility, they can interfere with the absorptionof a wide spectrum of drugs (eg, digoxin, theophylline,levodopa, cyclosporine). Antidopaminergic agents also evokehyperprolactinemia. Erythromycin and motilides accelerate gastricemptying, but they have a stimulatory effect on fundic toneand are associated with tachyphylaxis, which impedes theirlong-term use.

Although κ-opioid receptor agonists may be helpful in thetreatment of functional gastrointestinal disorders, they have notbeen studied extensively because of their antinociceptive properties;results of these studies have been inconclusive. Finally,5-HT4 receptor agonists improve gastric emptying withoutincreasing gastric fundus tone, which may contribute to symptomimprovement.