Pediatrics, the journal of the American Academy of Pediatrics has published a study1 examining the safety and tolerability of Pimecrolimus. Five if the six authors declare a conflict of interest stating they are either employed directly, consult for or receive grants from the manufacturer of pimecrolimus. The abstract and full paper are available online.
The study is an analysis of several sources of data including pharmacokinetic, double blind and open label studies. The study examined a total of 1133 patients, aged 3-23 months, who were followed up for a maximum of 2 years.
All but one of the studies was for 6 months or less with one longer term study lasting two years; one year blinded and one year open label follow up. Incidence Density rates were reported for adverse events that occurred in more than 1% of patients. The only adverse event that was statistically different was the increased risk of teething in patients using pimecrolimus, however there were tendencies to increased risk (although not significant) in several other areas.
The study separately examined skin infection rates and although there was little difference in the rate of bacterial infections of the skin there was an increased risk (again not significant) of viral and fungal skin infections.
The study also details that evidence of increased incidence of skin malignancies has not been seen in this study or in post marketing safety analyses. However, they also submit the conclusive evidence of safety with respect to this concern will only be available 5 to 10 years after product launch.
This study does go some way to reassuring prescribers of the safety of pimecrolimus however there is still a long way to go. Treatment withdrawals were not reported in this study and given that the paper states that 5million patients have been treated with pimecrolimus since launch a study of 1133 patients represents a very small cohort.
Action: Clinicians should continue to ensure that pimecrolimus is used within its product licence (Note: Pimecrolimus is not recommended for use in children under 2 years old) and the NICE Technology Appraisal recommendations.
- Paul C et al. Safety and Tolerability of 1% Pimecrolimus Cream Among Infants: Experience With 1133 Patients Treated for Up to 2 Years. Pediatrics 2006;117:e129-e131