Amoxicillin not working for uti what else could i take?

Depends on culture: The usual treatments for a simple, uncomplicated UTI include one of the following: 3 days of Bactrim, 3 days of ciprofloxacin, 7 days of nitrofurantoin, 7 days of Keflex, etc... One's doctor can tell from the urine culture result whether or not amoxicillin should or should not be effective in a patient's particular infection, but more likely one of the other antibiotics would be used.