This invention relates to 
aryl or heteroaryl amido 
alkane derivatives of formula (I)  in which Ar1 and Ar2 independently represent phenyl or a 5 or 6-membered heteroaromatic ring, R6 represents carboxyl or tetrazolyl, and the remaining variables are as defined in the text and claims, which are useful as an 
active ingredient of pharmaceutical preparations. The 
aryl or heteroaryl amido alkanes of the present invention have PGI2 antagonistic activity, and can be used for the prophylaxis and treatment of diseases associated with PGI2 activity. Such diseases include 
urological diseases or disorder as follows: bladder outlet obstruction, 
overactive bladder, 
urinary incontinence, detrusor hyper-reflexia, detrusor 
instability, reduced 
bladder capacity, frequency of micturition, 
urge incontinence, 
stress incontinence, bladder hyperreactivity, benighn prostatic hypertrophy (BPH), 
prostatitis, urinary frequency, 
nocturia, 
urinary urgency, pelvic hypersensitivity, 
urethritis, 
pelvic pain syndrome, prostatodynia, cystitis, or idiophatic bladder hypersensitivity. The compounds of the present invention are also useful for treatment of pain including, but not limited to 
inflammatory pain, 
neuropathic pain, 
acute pain, 
chronic pain, dental pain, premenstrual pain, 
visceral pain, 
headaches, and the like; hypotension;hemophilia and hemorrhage; and 
inflammation, since the diseases also relate to PGI2.