Brief Answer:
Information

Detailed Answer:
Hello XXXXXXX

Both Metronidazole and Nitrofurantoin have some risk of causing peripheral neuropathy, and taken them together increases that risk. It is considered a moderate risk, not an absolute contraindication.

Consider talking with her doctor about taking her off of the nitrofurantoin during the treatment with metronidazole, and shortly after while it is still in her system.

I also recommend, if not already prescribed, that you talk with her doctor about probiotics and specifically Saccharomyces boulardii, to help her with recovering from C. difficile infection.

Here is a somewhat old article on the subject, but still gives general information. If it doesn't "link", please copy and paste it into your address bar.

I hope your mother is feeling better very soon!

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Brief Answer:
Sorry, I didn't paste it.

Detailed Answer:
I'm sorry - here it is:

http://www.medscape.com/viewarticle/773413_6

and here is another article you may find useful:
https://www.researchgate.net/profile/Lynne_Mcfarland/publication/0000_Antibiotic_associated_diarrhea_risk_factors_and_reduction_of_incidence_by_the_yeast_Saccharomyces_boulardii/links/56e0875f08aee77a15fe9a6a.pdf

By the way, it's important for whatever might have caused or increased your mother's risk of C. difficile be resolved or eliminated. Often it is caused by an antibiotic. If it was possibly caused by the nitrofurantoin, then other ways to prevent UTIs should be considered such as sometimes, when there is atrophic urethritis from lack or estrogen after menopause, there is more risk of frequent UTIs. In that case, estrogen cream applied topically or intravaginally in a small dose can help (and if its a small dose used topically, usually it will not have the systemic problems caused by taking oral estrogen).

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