To evaluate the clinical characteristics of GAD patients with prominent GI symptoms (GI-high) and their response to pregabalin (PGB) treatment.

Data were pooled from 6 double-blind, placebo-controlled, 4-6 week trials of outpatients who met DSM-IV criteria for GAD with a minimum HAM-A total score ≥18. Treatment response was evaluated for 3 PGB fixed-dosage groups: 150 mg/d, 300-450 mg/d, and 600 mg/d. A GI-high subgroup (high GI symptomatology) was defined by a baseline HAM-A item-11 (GI) score ≥3 (severe/very severe).

At baseline, 261 patients (17%) met criteria for the GI-high subgroup, while 1294 patients (83%) were in the GI-low subgroup. Baseline characteristics were similar for the 4 study treatments in the GI-high subgroup. For the GI-high subgroup, LOCF-endpoint reduction in HAM-A was significantly higher on PGB-150, -13.8±1.7; PGB-300/450 -13.5±1.2; PGB-600, -14.8±1.1; vs PBO, -10.6±1.0 (P<0.0001 for all comparisons). In the GI-high subgroup, the proportion of patients showing a response in GI symptoms (HAM-A item 11 improving from severe/very severe to mild-to-none) was significantly higher on PGB-150 (62%), PGB-300/450 (73%), PGB-600 (68%) vs PBO (56%; P<0.0001 for all comparisons). The incidence of adverse events referable to the GI system was the same on PGB-150 and PBO, 8% higher on PGB-200/450 vs PBO, and 5% higher on PGB-600 vs PBO.

PGB was effective and well-tolerated in the subgroup of GAD patients presenting with severe GI symptoms. Treatment with PGB improved both overall levels of anxiety, as well as specifically improving GI symptoms.

Funded by Pfizer Inc