The link between sunshine and phototoxicity of sparfloxacin.

AIMS: To test the association between reporting rates for sparfloxacin-induced phototoxicity and sunlight u.v. exposure, and the effects of regulatory action.

METHODS

The reporting rates for phototoxicity with sparfloxacin to the French Pharmacovigilance System or to the Drug Manufacturer were compared with concurrent national mean u.v. exposure obtained from Météo-France, before and after the regulatory restrictions and warnings.

RESULTS

There were 371 severe phototoxic reaction reports during the first 9 months of marketing (reporting rate of 0.4 per thousand treated patients), approximately four to 25 times that reported for other fluoroquinolones. The reporting rate correlated highly (r = 0.873, P < 0.001) with the mean monthly u.v. exposure from sunlight (from Météo-France). Regulatory action including warnings for physicians, and restricted indications dramatically decreased the number of reports, but not the reporting rate.

CONCLUSIONS

This is the first demonstration of a strong association between sunlight exposure in a population and drug-induced phototoxicity. Regulatory action had no effect on the reporting rate (individual exposed patient risk), though it solved the public health issue.