Indoxacarb
Treatment of flea infestations (*Ctenocephalides felis*). Developing stages of fleas in the immediate environment are killed on contact. As indoxacarb is a pro-drug bioactivated by insect enzymes, it is very specific for insect cells. Formulations with permethrin also provide prevention of tick infestations (*Ixodes ricinus* and *Rhipicephalus sanguineus*). > **Clinical Pearl:** If ticks are present on the dog at the time of application, they may not be killed within 48 hours.
Mechanism: Acts on **voltage-dependent sodium channels** in susceptible insects. Indoxacarb is a pro-drug bioactivated by insect enzymes → the active component has a much higher affinity for insect sodium channels → highly specific for insect cells.
Dosing by species
- Fleas · 15 mg/kg (equivalent to 0.077 ml/kg Activyl or 0.1 ml/ kg Activyl Tick Plus) · topical · monthly
- Fleas · 25 mg/kg (equivalent to 0.128 ml/kg Activyl) · topical · monthly · The combined formulation (with permethrin) is not authorized for cats.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Dogs and cats < 8 weeks old
- Dogs < 1.5 kg (< 1.2 kg for Activyl plus)
- Cats < 0.6 kg
- Permethrin combination products must NOT be used on cats
Adverse effects
- Transient pruritus at the site of application
- Gastrointestinal signs (rare)
Monitoring
- Efficacy of flea/tick control
- Application site reactions
Overdose
No specific information provided in the monograph.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.