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.