UTI 200-400 mg daily in 1-2 divided doses for 1-10 days. Severe or complicated infection: Up to 600 mg daily & up to 20 days. Lower resp tract infection 200-600 mg daily in 1-3 divided doses for 3-10 days. Severe or complicated infection: Up to 800 mg daily & up to 20 days. Skin & soft tissue infection/O & G infection 400 mg daily for 7 days. Uncomplicated gonococcal urethritis Single dose of 200-400 mg. Non-gonococcal urethritis 400 mg daily for 9 days.