To further assess the possible CNS effects and abuse liability of prucalopride, its potential to increase or to antagonize the effects of the CNS convulsant pentylenetetrazol when coadministered, including tremors, tonic and clonic convulsions, and mortality, was evaluated in female SPF Wistar rats (weight, 110–120 g; age not documented; n=5 rats per dose of pentylenetetrazol) obtained from the breeding colonies of Johnson & Johnson, Beerse, Belgium. Rats were administered a single subcutaneous dose of prucalopride 40 mg/kg 1 hour before administration of intravenous doses of pentylenetetrazol (0, 5, 10, 20, 40, 80 or 160 mg/kg). An additional five female rats per dose group received the corresponding volume of solvent before administration of pentylenetetrazol. Tremors and convulsions were scored as 0 (absent), 1 (weak and delayed), 2 (weak but immediate), 3 (pronounced but delayed) or 4 (pronounced and immediate), and the 50% effective dose of pentylenetetrazol was calculated.