Does cefixime cure stds

Bactrim (Trimethoprim, sulfamethoxazole or co-trimoxazole) should not be used for STDs unless prescribed by a doctor in specific cases. It may not be effective at all for some STDs; and in general, it sometimes has serious side effects including liver damage. In addition, there is the problem of advancing antimicrobial resistance to it.
Co-trimoxazole is a combination of trimethoprim and sulfamethoxazole, a sulfa drug. It eliminates bacteria that cause various infections, including infections of the urinary tract, lungs (pneumonia), ears, and intestines. It also is used to treat traveler's diarrhea. Antibiotics will not work for colds, flu, or other viral infections.

Some STD's are viral and would not be affected by this medication.

(courtesy of the US national library of medicine)
yes
The antibiotic, Bactirm, is typically used for UTI and inner ear and bronchial infections. It is not typically prescribed for STD's.