It isn't unreasonable to keep patients on long-term nitrofurantoin when it's warranted, as in UTIs with reflux. This medication isn't linked with the development of resistant organisms and is generally well-tolerated. A few patients will have intestinal upset and, very rarely, a patient may develop pulmonary fibrosis.The oral cephalosporins such as cephalexin, on the other hand, are known to lead to resistance with long-term use, so they should be used with caution. I can see giving these drugs for longer periods in a pregnant woman when penicillin can't be used. In any case of recurrent UTIs, however, it's wise to search for predisposing factors, such as residual urine, stones, immunodeficiency, diabetes or debilitation. YT