Spending money recklessly can be quite problematic, and that's where the word "spendthrifts" comes into play. If you're looking for synonyms for this word, there are a variety of options at your disposal. For example, you might refer to someone as being "wasteful" or "extravagant." Alternatively, you could say that someone is "lavish" or "profligate" with their money. If you want to note that someone is spending money in a way that is somewhat careless or haphazard, you might use terms like "improvident" or "prodigal." Ultimately, any of these words would be a suitable substitute for "spendthrifts," depending on the context in which they are employed.