Digitoxin is a well-known cardiac glycoside that is widely used to treat heart failure and certain cardiac arrhythmias. However, there are various synonyms for digitoxin which can be used interchangeably. For instance, popular synonyms for digitoxin include digitalin, digoxin, digitonin, and ouabain. These terms are often used interchangeably by medical practitioners and pharmacists depending on the context. It's important to note that while these synonyms may share similar qualities and therapeutic applications, they may also differ in potency and pharmacokinetics. Therefore, it is crucial for healthcare professionals to understand the nuances of each synonym and its specific use.