Any serious side effects of levofloxacin pharex?

Levofloxacin. Yes - this is a fluoroquinolone antibiotic, and like all antibiotics and medications should only be taken under the supervision of a doctor. Hopefully your prescription is only short term (like for a UTI) but some side effects can occur. A serious but rare side effect is tendon-rupture. There can also be nausea, vomiting, headaches, rash, yeast infections, diarrhea etc. Hope this helps.