Ivermectin
Ivermectin for animals belongs to the Avermectin class of antiparasitic medications. Ivermectin is active against intestinal parasites, mites, bots, heartworm microfilaria, and developing larvae. Ivermectin has no effect on trematode and cestode parasites.
Group
Ivermectin is grouped as an Antiparasitic drug.
Mechanism of Action
Ivermectin causes neurotoxicity in parasites by enhancing their glutamate-gated chloride ion channels. Increased permeability to chloride ions and hyperpolarization of nerve cells result in the paralysis and death of the parasite.
Ivermectin is active against intestinal parasites, mites, bots, heartworm microfilaria, and developing larvae. Ivermectin has no effect on trematode and cestode parasites. Ivermectin can also produce heartworm adulticide effects when administered long term.
Dose Rates
Dose rate of ivermectin in dogs-
- Heartworm preventative: 6 mcg/kg every 30 days PO
- Heartworm treatment: Ivermectin administered at preventive doses combined with doxycycline at 10 mg/kg PO per day for 28 days
- Ectoparasite therapy: 200–400 mcg/kg IM, SQ, or PO
- Endoparasite therapy: 200–400 mcg/kg weekly SQ, PO
- Demodicosis therapy: Start with 100 mcg/kg/day and increase dose by 100 mcg/kg/day to 600 mcg/kg/day for 60–120 days PO (Successful treatment is confirmed with negative skin scrapings)
- Sarcoptic mange and cheyletiellosis therapy: 200–400 mcg/kg every 7 days PO
Dose rate of ivermectin in Cats-
- Heartworm preventive: 24 mcg/kg every 30 days PO
- Ectoparasite therapy: 200–400 mcg/kg IM, SQ, or PO, every 7 days or as needed based on skin scraping and clinical examination
- Endoparasite therapy: 200–400 mcg/kg weekly SQ, PO
- Topical Use: 0.5 mL per ear (0.1 mg/mL) for treating ear mites
Dose rate of ivermectin in other animals-
- Horses: 200 mcg/kg IM, SC, PO
- Cattle: 200 mcg/kg SQ, PO
- Pigs: 300 mcg/kg SQ, PO
- Sheep and Goats: 200 mcg/kg SQ, PO
Ivermectin has a prolonged half-life in all the animals studied, which allows for infrequent administration to achieve clinical effects.
Indications
Ivermectin is used in horses for the treatment and control of:
- Large strongyles (adult) (Strongylus vulgaris, Strongylus edentatus, and Triodontophorus spp.)
- Small strongyles (adult and fourth-stage larvae) (Cyathostomum spp., Cylicocyclus spp., Cylicostephanus spp.)
- Pinworms (adult and fourth-stage larvae) (Oxyuris equi)
- Large roundworms (adult) (Parascaris equorum)
- Hairworms (adult) (Trichostrongylus axei)
- Large-mouth stomach worms (adult) (Habronema muscae)
- Neck threadworms (microfilariae) (Onchocerca spp.)
- Stomach bots (Gastrophilus spp.)
Ivermectin is used in Cattle for the treatment and control of:
- GI nematodes (adults and fourth-stage larvae) (Haemonchus placei, Ostertagia ostertagi) (including inhibited larvae), Ostertagia lyrata, T. axei, T. colubriformis, Cooperia oncophora, Cooperia punctata, Cooperia pectinata, Oesophagostomum radiatum, Nematodirus helvetianus (adults only), Nematodirus spathiger (adults only), Bunostomum phlebotomum;
- lungworms (adults and fourth-stage larvae) (Dictyocaulus viviparus); grubs (parasitic stages) (Hypoderma bovis, H. lineatum)
- Sucking lice (Linognathus vituli, Haematopinus eurysternus, Solenopotes capillatus)
- Mites (scabies) (Psoroptes ovis [syn. P. communis var. bovis], Sarcoptes scabiei var. bovis).
Ivermectin is used in Pigs for the treatment and control of:
- GI roundworms (adults and fourth- stage larvae) large roundworm, Ascaris suum; red stomach worm, Hyostrongylus rubidus
- Nodular worm, Oesophagostomum species
- Threadworm, Strongyloides ransomi (adults only)
- Somatic roundworm larvae (threadworm, S. ransomi [somatic larvae])
- Lungworms (Metastrongylus spp. [adults only])
- Lice (H. suis)
- Mites (Sarcoptes scabiei var. suis)
Ivermectin is used in Small animals (dog and cats) for the treatment and control of:
- Heartworm preventative (low dose)
- To treat external parasites (mites) and intestinal parasites at higher doses
- Ivermectin is an effective microfilaricide after adulticide therapy (for optimal heartworm adulticide effect, it is often administered with oral doxycycline @ 10 mg/kg per day for 28 days)
- Treatment of Demodex infections is effective but requires higher doses than for any other indication
Contraindications
Ivermectin for animals is not used in the following situations:
- Animals younger than 6 weeks (1.5 months / 42 days) of age
- Ivermectin sensitive animals
Interactions
Ivermectin shouldn’t be used with medications that could make it more permeable to the blood-brain barrier. These medications include of calcium-channel blockers, cyclosporine, itraconazole, and ketoconazole.
Adverse effects
- Hypersalivation
- Depression
- Ataxia
- Retinopathy (Difficulty with vision, mydriasis, or both may occur, but recover if the drug is discontinued)
- Itching and allergic effects can occur due to the impact of ivermectin on heavy microfilariae infestation, as it triggers an immune response.
Toxicity
Toxicity may occur at high doses and in breeds in which ivermectin crosses the blood-brain barrier. Sensitive breeds include Collies, Australian shepherds, Old English sheepdogs, long-haired whippets, and Shetland sheepdogs. Toxicity is neurotoxic, and signs include hypersalivation, depression, ataxia, difficulty with vision, coma, and death.
Treatment of intoxication includes the use of activated charcoal, symptomatic treatment like management of seizures and ventilation support, lipid emulsion, etc.
Preparations
Following are the ivermectin preparations available for animals:
- Inj. Neomec 1mL,10mL and 100mL vials with 10mg/mL concentration
- Inj. Hitek 1mL, 10mL, 30mL, 50mL and 100mL vial with 10mg/mL concentration
- Pow. Avertin 5gm sachet with 1%w/w concentration
- Tab. Neomec 10mg
- Tab. Hitek 80mg
Following are the ivermectin combination preparations available for animals:
- Inj. Neomec SX 10mL vial with 10mg/mL ivermectin and 100mg/mL clorsulon concentration
- Inj. Endact Plus 10mL vial with 10mg/mL ivermectin and 100mg/mL clorsulon concentration
- Inj. Hitek F 10mL vial with 10mg/mL ivermectin and 100mg/mL clorsulon concentration
- Inj. Neomec LA 10mL vial with 31.5mg/mL ivermectin, 0.18% w/v methyl paraben, 0.02% w/v propyl paraben concentration
- Inj. Hitek Platinum 10mL vial with 31.5mg/mL ivermectin, 0.18% w/v methyl paraben, 0.02% w/v propyl paraben concentration
- Inj. Endact LA 10mL vial with 31.5mg/mL ivermectin, 0.18% w/v methyl paraben, 0.02% w/v propyl paraben concentration
- Bol. Fendikind Plus (Each bolus contains 3000mg Fenbendazole and 100mg Ivermectin)
More about ivermectin for animals
Ivermectin never given in i/v (intravenous) route of administration.