Functional dyspepsia (FD) is a common functional gastrointestinal disorder characterized by upper abdominal discomfort/pain and/or symptoms of meal-related fullness/satiety. There is currently no definitive therapy that is beneficial for all FD patients. Accumulating evidence suggests efficacy for tricyclic antidepressants (TCAs) in FD. However, no firm conclusion can be drawn currently due to the relatively small amount of studies and large heterogeneity between studies. In addition, TCAs are often associated with side effects, which occur early after initiation of therapy preceding the therapeutic effect and often result in discontinuation of the therapy. These side effects are related to drug metabolism, which depend on polymorphisms of the cytochrome P (CYP) enzyme system.
Treatment with the 2nd generation TCA nortriptyline results in adequate relief of symptoms in FD. In addition, treatment can be optimized by maximizing therapeutic efficacy and decreasing the occurrence and severity of side effects through personalization of the drug based on the basis of CYP genotype-based tailored dose adjustments.
Randomized double-blind placebo-controlled trial with three arms
STUDY POPULATION/SAMPLE SIZE
198 patients with functional dyspepsia without evidence of psychiatric disease
Nortriptyline in classical dose vs tailored CYP-based dose vs placebo. Treatment period 12 weeks and follow-up period 6 months.
Primary outcome measure will be self-reported adequate relief (defined as a yes/no response in at least 50% of weeks 3-12 of the treatment). Secondary outcomes will include response to therapy defined by the weekly average of the daily symptoms scores. All endpoint analyses will be based on the intention to treat population. The proportion of responders in each treatment group will be compared using logistic regression to provide covariate adjustments for centers, gender, age etc. in the analyses.