Provided is the treatment of obesity and related conditions using (R)-8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (lorcaserin), with consideration of a patient&rsquos renal function. It appears that patients with severe renal impairment or end stage renal disease (ESRD) are exposed to greater metabolite levels when they are administered lorcaserin so the use of lorcaserin is contraindicated in these patients.