Fipronil is an insecticide and acaricide belonging to the phenylpyrazole family. It acts by inhibiting the GABA complex, binding to the chloride channel and thereby blocking pre- and post-synaptic transfer of chloride ions across cell membranes. This results in uncontrolled activity of the central nervous system and death of insects or acarids.
Fipronil exhibits an insecticidal and acaricidal activity against fleas (Ctenocephalides spp) and ticks (Rhipicephalus spp, Dermacentor spp, Ixodes spp. including Ixodes ricinus) in the dog.
Fleas will be killed within 24 h. Ticks will usually be killed within 48 h after contact with fipronil, however if ticks of some species (Rhipicephalus sanguineus and Ixodes ricinus) are present when the product is applied, all the ticks may not be killed within the first 48 hours.
Fipronil is mainly metabolised to its sulfone derivative (RM1602), which also possesses insecticidal and acaricidal properties. The concentrations of fipronil on the hair decrease with time.
Fleas from pets often infest the animal's basket, bedding and regular resting areas such as carpets and soft furnishings which should be treated, in case of massive infestation and at the beginning of the control measures, with a suitable insecticide and vacuumed regularly.
The product does not prevent ticks from attaching to the animals. If the animal has been treated prior to exposure to the ticks, the ticks will be killed in the first 24-48 hours after attachment. This will usually be prior to engorgement, minimising but not excluding the risk of transmission of diseases. Once dead, ticks will often drop off the animal, but any remaining ticks may be removed with a gentle pull.
Shampooing an hour prior to treatment does not affect the efficacy of the product against fleas.
Bathing/immersion in water within two days after application of the product should be avoided. Weekly immersion in water for one minute reduces the period of persistent insecticidal efficacy against fleas by one week.
For optimum control of flea problems in a multi-pet household, all dogs and cats in the household should be treated with a suitable insecticide.
Laboratory studies using fipronil have not shown any evidence of teratogenic or embryotoxic effect. Studies have not been carried out with this product in pregnant and lactating bitches. Use in pregnancy and lactation only in accordance with professional veterinary advice and a benefit/risk assessment.
No adverse effects were observed in target animal safety studies in 2 month-old puppies, growing dogs and dogs weighing about 2 kg treated with the therapeutic dose on five consecutive days. The risk of adverse effects may increase in cases of overdose. No known incompatibilities exist for the use of concurrently administered medicinal products.
The alcohol carrier may have adverse effects on painted, varnished or other household surfaces or furnishings.