ACE and congestive heart failure: Metformin is an oral biguanide drug, and glipizide is an oral, rapidly absorbed, short-acting sulfonylurea drug.[17] Captopril, an angiotensin-converting enzyme inhibitor, or valsartan, an angiotensin II receptor antagonist, was used to control hypertension and albuminuria, both of which have been used to treat hypertension and congestive heart failure.[18,19] Simvastatin or fenofibrate was used to treat dyslipidemia, as described previously.[20,21]