Clinical trials
found that when phentermine–topiramate plus lifestyle
modification was used for just over a year, associated
weight change ranged from −8.1 kg, or
−17.9 lbs. (least-squares mean −7.8%; 95% CI,
−8.5 to −7.1 kg, P < 0.0001), in patients assigned
to phentermine 7.5 mg plus topiramate 46 mg, to
−10.2 kg, or −22.5 lbs. (least-squares mean −9.8%;
95% CI, −10.4 to −9.3 kg, P < 0.0001), in patients assigned
to phentermine 15 mg plus topiramate 92 mg