A comparison of the photosensitizing potential of trovafloxacin with that of other quinolones in healthy subjects

Treatment with some quinolones is associated with an abnormal skin reaction following exposure to sunlight (photosensitivity). The objective of the cu rrent study was to compare the photosensitizing potential of a new quinolon e, trovafloxacin, with that of ciprofloxacin, lomefloxacin and placebo. For ty-eight healthy males (age range 19-45 years) were randomized to receive a 7 day course of treatment with: (i) trovafloxacin 200 mg od; (ii) ciproflo xacin 500 mg bd; (iii) lomefloxacin 400 mg od; or (iv) placebo bd. Minimal erythema doses (MEDs) were assessed using a monochromator at baseline and o n day 5 of treatment, for wavelengths of 305 +/- 5, 335 +/- 30, 365 +/- 30, 400 +/- 30 and 430 +/- 30 nm; 335 +/- 30 and 365 +/- 30 nm are within the UVA range. Immediate reaction MEDs were similar in all treatment groups. Ho wever, between baseline and day 5, the mean decreases in delayed-reaction M ED (24 h) at 335 +/- 30 nm were only 18.99% for trovafloxacin versus placeb o (P = 0.1267), compared with 53.77% (P less than or equal to 0.0001) and 6 4.13% (P less than or equal to 0.0001) for ciprofloxacin and lomefloxacin, respectively. Similarly, at 365 +/- 30 nm, trovafloxacin produced the small est reduction in delayed MED versus placebo (43.66%), compared with ciprofl oxacin (61.53%) and lomefloxacin (75.81%). These differences between trovaf loxacin and ciprofloxacin and lomefloxacin were significant at both 335 +/- 30 and 365 +/- 30 nm (P less than or equal to 0.029). All MED values retur ned to baseline levels within 2 days of drug cessation. These results show that trovafloxacin has significantly less photosensitizing potential than e ither ciprofloxacin or lomefloxacin. This photosensitivity appears to be in duced only by wavelengths in the UVA region, is maximal at 24 h and is a sh ort-term effect.