Provided are a condensed pyridine derivative having a serotonin 5-HT
2C
receptor activation action, a prophylactic or therapeutic agent for a lower urinary tract symptom, obesity and/or organ prolapse and the like containing the condensed pyridine derivative, a screening method for a substance that increases leak point pressure upon a rise in the intravesical pressure or a prophylactic or therapeutic drug for stress urinary incontinence, a prophylactic or therapeutic drug for cystoceles or enteroceles, containing a substance that activates serotonin 5-HT
2C
receptor, and a method of screening for a therapeutic drug for cystoceles or enteroceles, including increasing an intravesical pressure after bilateral transection of the hypogastric nerve and pudendal nerve of an animal, and measuring a closure response in the urethra, the rectum or the vagina observed at that time. A serotonin 5-HT
2c
receptor activator containing a compound represented by the formula:
wherein each symbol is as defined in the specification, or a salt thereof.
Described is a method of screening for a drug for the prophylaxis or treatment of cystoceles or enteroceles, comprising increasing an intravesical pressure after bilateral transection of the hypogastric nerve and pudendal nerve of an animal, and measuring a closure response in the urethra, the rectum or the vagina observed at that time.