PHOTOSENSITIZING POTENTIAL OF OFLOXACIN

Background. The relative phototoxic risk of ofloxacin, one of the newe r fluoroquinolones, was compared with that of an active control of kno wn but low phototoxic risk, naproxen. Methods. A randomized, controlle d, open-label trial was used with a standardized phototoxic assay comp leted at baseline, midway through, and at the termination of the 12-da y trial. The trial was held at a dermatology research laboratory locat ed at a large tertiary referral and teaching hospital. Thirty healthy volunteers who met the inclusion criteria and met none of the exclusio n criteria were enrolled. Twenty-seven patients completed the trial. T hree subjects failed to complete the trail. One subject developed an e xaggerated response from the study. The other two subjects failed to r eturn for follow-up visits. Results. Both ofloxacin and the active con trol agent, naproxen, significantly increased the subjects' response t o the tested solar and ultraviolet irradiation. There was, however, no significant difference between the responses observed for ofloxacin v ersus naproxen at any time. Conclusions. Ofloxacin possesses a definit e but low potential to cause phototoxic reactions in humans. These stu dy data, in concert with surveillance data, suggest a hierarchy of pho totoxic risk among the fluoroquinolones: fleroxacin >> lomefloxacin, p efloxacin >> ciprofloxacin > enoxacin, norfloxacin, ofloxacin. The imp act that phototoxicity risk will have on selecting the optimum member of a large drug family appears to be substantial in outpatient and amb ulatory settings and minimal in inpatient settings.