Nitrofurantoin

Although most people have probably never heard of it, nitrofurantoin has been around since the early 1950s. It is prized for its mild impact on gastrointestinal flora and for its high degree of effectiveness against the E. coli bacteria.

What we like: If your UTI is a result of the E. coli bacteria, nitrofurantoin is often a good choice. Unlike a number of different antibiotics, nitrofurantoin is not likely to cause stomach distress.

Flaws: While nitrofurantoin is generally effective for most UTIs, it is not so effective for treating kidney infections.