ChEBI: Sulmazole is an imidazopyridine that is 1H-imidazo[4,5-b]pyridine which is substituted at position 2 by a 2-methoxy-4-(methylsulfinyl)phenyl group. An A1 adenosine receptor antagonist, it was formerly used as a cardiotonic agent. It has a role as a cardiotonic drug, an EC 3.1.4.* (phosphoric diester hydrolase) inhibitor and an adenosine A1 receptor antagonist. It is an imidazopyridine and a sulfoxide.