Intravesical Gentamicin to Prevent Recurrent UTI

Inclusion criteria: * Postmenopausal * 2 UTIs in 6 months * desire to start antibiotic prophylaxis to prevent UTIs Exclusion criteria: * Parkinsons disease * myasthenia gravis * renal failure * liver failure * bladder pain syndrome * multiple negative urine cultures associated with UTI symptoms (\>/= 3) * bladder Botox treatments in the past * treatment planned for UI and prolapse * unevaluated microscopic hematuria * history of kidney stones * no antibiotics within 4 weeks * most recent weight \<40kg (88.18lbs) * surgically altered urinary tract (urinary diversion, phalloplasty, etc) * allergy or hypersensitivity to either of the study medications or medications in the same family including but not limited to: amikacin, kanamycin, neomycin, paromomycin, streptomycin, tobramycin.