If oral ingestion occurs, seek medical advice immediately.
Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in clinical practice.
Comfortis Topical Suspension was studied in two randomized, active-controlled trials (N=552) in subjects with head lice; the results are presented in Table 1.
Table 1: Selected Adverse Events Occurring in at least 1% of Subjects
| Signs | Spinosad (N=552) | Permethrin 1% (N=457) |
| Application site erythema | 17 (3%) | 31 (7%) |
| Ocular erythema | 12 (2%) | 15 (3%) |
| Application site irritation | 5 (1%) | 7 (2%) |
Other less common reactions (less than 1% but more than 0.1%) were application site dryness, application site exfoliation, alopecia, and dry skin.
Systemic safety was not assessed in pediatric subjects under 6 months of age as laboratory parameters were not monitored in these controlled studies.
The pharmacodynamics of Comfortis Topical Suspension has not been studied.
An open-label, single-center trial was conducted over a period of seven days to determine the pharmacokinetic profile of spinosad 1.8% in pediatric subjects with head lice infestation. Fourteen (14) subjects, 4 – 15 years of age, with head lice were enrolled into the trial. All subjects applied a single topical (scalp) treatment of spinosad 1.8% for 10 minutes, after which the test article was washed off, and subjects underwent plasma sampling. Results demonstrated that spinosad was below the limit of quantitation (3ng/mL) in all samples. Plasma concentration of benzyl alcohol was not determined in these subjects.
An open-label, two-center trial was conducted over a period of 23 days to determine the pharmacokinetic profile of spinosad 0.9% and the ingredient benzyl alcohol in pediatric subjects with a head lice infestation. Twenty-six (26) subjects between 6 months to 4 years of age were enrolled into the study per protocol. All subjects applied a single topical (scalp) treatment of spinosad 0.9% for 10 minutes, after which the test article was washed off, and subjects underwent plasma sampling over a 12 hour period. Plasma spinosad concentrations were below the limit of quantitation (3 ng/mL) in all samples.
Benzyl alcohol was quantifiable (above 1 μg/mL) in a total of 8 plasma samples in 6 out of 26 subjects (25%): four out of 12 subjects in the 6 months to < 2 years age group and two out of 14 subjects in the 2 to 4 years age group. The highest observed concentration was 2.37 μg/mL. Benzyl alcohol concentrations at 12 hours post-treatment were below limit of quantification (1 μg/mL) for all subjects.
