Pharmacotherapeutic group
Dermatological; antiseptics and disinfectants.
ATC Vet Code: QD08AX01
Pharmacodynamic properties
Water containing hydrogen peroxide may diffuse into the body of the lice or be drawn into the gut by normal biological processes, e.g. feeding.
Once within the body of the louse, dissociation of the hydrogen peroxide in to oxygen and water may cause temporary or permanent disruption to internal structures, causing the parasite to detach from the host.
Resistance to hydrogen peroxide has been reported on one farm after fish were treated with hydrogen peroxide regularly (41 treatments) over a 6 year period. The proposed mechanisms of resistance were genetic selection of individuals with a cuticle that provides a barrier to penetration by hydrogen peroxide or the presence of detoxifying enzymes.
Pharmacokinetic properties
Absorption
As hydrogen peroxide is administered typically as a 20 minute bath treatment, absorption by the host is considered to be negligible.
Distribution
Not applicable.
Biotransformation
The possibility of any biotransformation is small, due to the unlikelihood of absorption occuring, and hydrogen peroxide being broken down by catalase and other enzymes. These may be considered as natural routes of detoxification and would occur very rapidly.
Elminiation
As above, break down of any hydrogen peroxide residual would be enzymic. Excretion of hydrogen peroxide would not occur.