Selamectin

Antiparasitics

A topical (spot-on) antiparasitic of the macrocyclic lactone (avermectin) class. It binds to glutamate-gated chloride channels in parasites, paralyzing and killing them. It is used in dogs and cats against fleas, some mites, certain worms, and for heartworm prevention.

Drug class
Antiparasitics
Registered species
2
Recorded effects
16
Related products
0

Pharmacological information

A class-level scientific overview for general reference — no doses. The ultimate reference is always the locally approved product leaflet and consultation with a veterinarian.

Mechanism of action

A topical (spot-on) antiparasitic of the macrocyclic lactone (avermectin) class. It binds to glutamate-gated chloride channels in parasites, paralyzing and killing them. It is used in dogs and cats against fleas, some mites, certain worms, and for heartworm prevention.

Indications

  • Fleas, ear mites, and some forms of mange
  • Prevention of heartworm disease

Contraindications & warnings

  • Not used in animals younger than the authorized age
  • Caution in sick or convalescing animals per the label

Drug interactions

  • Its neurological effect may be aggravated by drugs that enhance GABA activity

Recorded adverse effects

openFDA veterinary reports — the numbers are report counts, not a severity rate.

Dogs

INEFFECTIVE, HEARTWORM LARVAE7,937
Lack of efficacy (ectoparasite) - flea3,272
Vomiting2,892
Depression1,876
Diarrhoea1,730
Lack of efficacy (endoparasite) - hookworm1,628
Anorexia1,483
Pruritus1,427

Cats

Application site alopecia5,234
Lack of efficacy (ectoparasite) - flea2,228
Vomiting2,178
Application site hair loss2,151
Anorexia1,886
Depression1,678
Lethargy (see also Central nervous system depression in 'Neurological')1,309
Application site lesion1,175

Sources