First Option
Nitrofurantoin (Macrobid) 100 mg po BID x 5 days. — (Avoid if early pyelonephritis suspected.)
Trimethoprim/sulfamethoxazole (Bactrim) 160/800 mg BID x 3 days.—(avoid if resistance prevalence is known to exceed 20 or if used for UTI in previous 3 months)
Fosfomycin 3-g single dose. —(lower efficacy than some other recommended agents; avoid if early pyelonephritis suspected)
Pivmecillinam 400 mg bid x 5 days—(lower efficacy than some other recommended agents; avoid if early pyelonephritis suspected)
Related Article: FDA Warnings for fluoroquinolones.
Second Option
A) Fluoroquinolones
Ciprofloxacin 250 mg BID x 3 days
Ciprofloxacin extended-release (Cipro XR) 500 mg QD x 3 days.
Levofloxacin 250 mg QD x 3 days
Ofloxacin 200 mg QD x 3 days. OR 400-mg single dose
OR
B) Beta-Lactams—(avoid ampicillin or amoxicillin alone; lower efficacy than other available agents; requires close follow-up)
Amoxicillin/clavulanate (Augmentin) 500/125 mg BID x 7 days.
Cefdinir (Omnicef) 300 mg BID x 10 days.
Cefpodoxime 100 mg BID x 7 days.
Pregnancy categories.
Fosfomycin = B; Nitrofurantoin = B; Bactrim = C
All quinolones are Preg cat C
References
2010 IDSA Guidelines
Am Fam Physician. 2011 Oct 1;84(7):771-776. http://www.aafp.org/afp/2011/1001/p771.html