Sarolaner
Sarolaner is an isoxazoline-class ectoparasiticide used for the treatment and prevention of flea, tick, and mite infestations in dogs and cats. It is available as a standalone oral tablet for dogs (Simparica) and in combination with selamectin as a topical spot-on for cats (Stronghold Plus). > **Important:** Parasites need to start feeding on the host to become exposed to sarolaner; therefore, the transmission of infectious parasite-borne diseases cannot be completely excluded. **Clinical Pearl:** Isoxazolines have revolutionized the treatment of demodicosis and sarcoptic mange due to their high efficacy and ease of use. However, as a class effect, they should be used with caution in animals with a known history of seizures or neurologic disorders.
Mechanism: Sarolaner acts at **ligand-gated chloride channels**, specifically those gated by the neurotransmitter **gamma-aminobutyric acid (GABA)** and glutamate. Binding to these receptors → blocks pre- and post-synaptic transfer of chloride ions across cell membranes → causes uncontrolled neuromuscular activity → leads to the death of the parasite. It has highly selective toxicity for arthropods compared to mammals.
Dosing by species
- Treatment of fleas, ticks, ear mites (Otodectes cynotis), demodicosis (Demodex canis), and Sarcoptes scabiei · 2-4 mg/kg · PO · monthly · Monthly (duration depends on parasite targeted) · Administer every month.
- Treatment of fleas, ticks, ear mites, biting lice, adult roundworms, adult hookworms, and prevention of heartworm disease · 1 mg/kg sarolaner (with 6 mg/kg selamectin) · topical · monthly · Monthly · Administer monthly using the combination spot-on product.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Dogs < 8 weeks of age
- Dogs < 1.3 kg body weight
- Cats < 8 weeks of age
- Cats < 1.25 kg body weight
- Known hypersensitivity to the active substance
Adverse effects
- Mild gastrointestinal signs (vomiting, diarrhea)
- Mild pruritus or alopecia at the site of application (spot-on product)
- Neurologic signs (tremors, ataxia, seizures) - rare class effect of isoxazolines
Drug interactions
- NSAIDs · Sarolaner is highly bound to plasma proteins and might compete with other highly bound drugs, potentially increasing free fractions. · moderate
- Warfarin · Potential competition for plasma protein binding sites. · moderate
- Milbemycin oxime · No interactions observed when co-administered. · null
- Moxidectin · No interactions observed when co-administered. · null
- Pyrantel pamoate · No interactions observed when co-administered. · null
Monitoring
- Efficacy of parasite control
- Monitor for gastrointestinal upset after administration
- Monitor for neurological signs in susceptible individuals
Overdose
Overdose may increase the risk of adverse effects, particularly gastrointestinal signs (vomiting, diarrhea) and potentially neurological signs (tremors, ataxia, seizures). Treatment is symptomatic and supportive as there is no specific antidote.
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.