Objectives: The authors investigated if timing of medical treatment is associated with the analgesic effect of pregabalin or placebo in patients with chronic pancreatitis (CP).
Methods: Sixty-four patients received pregabalin (150-300 mg twice a day) or matching placebo for 3 consecutive weeks. Responders to treatment were defined as patients with a reduction in clinical pain scores of 30% or greater. Factors associated with timing of pain treatment (ie, duration of CP and opioid usage) were collected at baseline. In addition, other factors that potentially could influence outcome (eg, clinical pain scores prior to study medication, diabetes, and exocrine pancreatic insufficiency) were also included. Conventional groupwise logistic regression and analysis on the individual patient level with a machine learning technique were used to predict treatment response.
Results: In the conventional statistical analysis duration of CP (odds ratio, 0.9; 95% confidence interval, 0.8-1.1; P = 0.3) and opioid treatment (odds ratio, 1.0; 95% confidence interval, 0.9-1.1; P = 0.6) were not associated with pain relief. In addition, none of the supplementary factors were associated with treatment response (all P > 0.1). Likewise, in the individual patient-level analysis, none of the included variables reached classification accuracies greater than chance level (all P > 0.1).
Conclusions: Pregabalin can be added as adjuvant analgesic at any time point during the disease course of CP.