What the hell is this! Anyone? Peach round pfizer one side adn 25 other.. ## Hello, The closest match I've been able to find is Inspra (25 mg). It is a diamond shaped, light yellow pill with the imprint Pfizer on one side and NSR 25 on the other. It is manufactured by Pfizer and has a National Drug Code of 00025-1710. Inspra contains the active ingredient Eplerenone, which is an aldosterone antagonist used as an adjunct in the management of chronic heart failure. It is similar to the diuretic spironolactone, though it is much more selective for the mineralocorticoid receptor in comparison (i.e., does not possess any antiandrogen, progestogen, or estrogenic effects), and is specifically marketed for reducing cardiovascular risk in patients following myocardial infarction. Common adve...