Conflicting references regarding porphyrinogenicity, but the systemic load probably is insignificant, being about 1/500 of the peroral dose of 250mg.

Quinolone chemotherapeutic in eye drops 3mg/mL, used in treatment of corneal vulnera and conjunctivitis (2 drops every 15 minutes during the first 6 hours, after that 2 drops every 30 minutes the rest of the day, etc. Continued for two weeks). Absorbed, but the plasma concentration is low, varying between 0 and 4,7 µg/mL.

Uneventful use reported in 1 patient with acute porphyria.