Brand: NEOPRINIL ® 5 mg/mL Pour-on
INDICATIONS: CATTLE, beef & dairy
PARASITES CONTROLLED* (spectrum of activity)
* Country-specific differences may apply: read the product label.
- Gastrointestinal roundworms (adults and L4 larvae): Ostertagia ostertagi (incl. inhibited larvae), Ostertagia lyrata (adults only), Haemonchus placei, Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus longispicularis (adults only), Bunostomum phlebotomum, Cooperia onchophora, Cooperia pectinata, Cooperia punctata, Cooperia surnabada, Nematodirus helvetianus, Oesophagostomum radiatum, Trichuris spp (adults only).
- Lungworms (adults and L4 larvae): Dictyocaulus viviparus.
- Cattle grubs (warbles, parasitic stages): Hypoderma bovis, Hypoderma lineatum.
- Sucking & biting lice: Linognathus vituli, Haematopinus eurysternus, Solenopotes capillatus, Bovicola (Damalinia) bovis
- Mites (scabies): Chorioptes bovis, Sarcoptes scabiei var. bovis.
- Horn flies: Haematobia irritans irritans
- Residual effect (significant country differences: read the product label!):
*Can be slightly different in some countries: read the product label!
- Cattle: 500 mcg/kg bw, equivalent to 1 ml/10 kg bw
- LD50 (acute oral) in rats: >5000 mg/kg (estimate according to the LD50 of the active ingredient)
- Estimated hazard class according to the WHO: not applicable for veterinary medicines
Suspected poisoning? Read the article on eprinomectin safety in this site.
Withholding periods (=withdrawal times) for meat & milk (country-specific differences may apply: read the product label)
- Meat: UK & EU 15 days.
- Milk for human consumption: UK & EU: NIL.
WARNING !!!: Never use on humans, dogs and cats
You may be interested in the following articles in this site dealing with the general safety of veterinary products:
- Safety for humans
- Safety for domestic animals
- Safety for the environment
- Hazard classifications of pesticides
Risk of resistance? YES, reported for ivermectin in gastrointestinal roundworms in cattle in several countries, particularly in the following worm species: Cooperia spp and Ostertagia spp, whereby cross-resistance between eprinomectin and ivermectin must be assumed.
Based on the very abundant and frequent use of ivermectin and other macrocyclic lactones (with cross-resistance to ivermectin) in livestock it must be assumed that resistance of these roundworms to this chemical class will continue spreading and strengthening in the future.
This means that if this product does not achieve the expected efficacy against the mentioned parasites, it may be due to resistance and not to incorrect use, which is usually the most frequent cause of product failure.
- Benzimidazoles, e.g. albendazole, febantel, fenbendazole, oxfendazole, etc. Similar or even worse resistance problems than ivermectin
- Imidazothiazoles, mainly levamisole. etc. Similar or even worse resistance problems than ivermectin
- Nitroxinil (limited spectrum of activity)
- Tetrahydropyrimidines, e.g. morantel, pyrantel (limited spectrum of activity)
- Salicylanilides, e.g. closantel (limited spectrum of activity)
These alternative products may not be available in all countries, or may not be available as pour-ons.
Are the active ingredients of this product ORIGINAL* or GENERICS**?
*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.
COUNTRIES where this brand/product is marketed (maybe under another TM): UK and EU countries
GENERIC BRANDS available? YES, but rather few and not in all countries. This brand with generic eprinomectin is marketed by VIRBAC in the UK and other EU countries.
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used antiparasitic pour-on brands click here.
NEOPRINIL 5 mg/mL Pour-on Solution is VIRBAC'S generic version of EPRINEX (in some countries IVOMEC EPRINEX) from MERIAL.
Eprinomectin was introduced in the 1990s (by MERIAL). It was the first macrocyclic lactone approved for use on dairy cows because it does not leave significant residues in milk, in contrast with all ivermectin-based products.
All pour-ons with macrocyclic lactones, including this one have general disadvantages compared with the corresponding injectables. In several scientific studies it has been shown that ivermectin administered as a pour-on is not "automatically" absorbed through the skin. Licking (self licking or licking of other treated animals) may account for >50% of the total intake, compared with only about 10% absorbed directly through the skin. This is the reason why a dose of 500 mcg/kg bw is needed after pour-on treatment, compared with only 200 mcg/kg bw after injection. And it has been also shown that intake of topically administered active ingredient in some cattle may be twice as high as in other ones, all treated at the same rate. The reason is that individual cattle show a different licking behavior. An important practical consequence is that the quantity that is finally ingested and is therefore available for the control of gastrointestinal worms depends on the licking behavior of the treated animals. "High lickers" can be overdosed, whereas "low lickers" can be underdosed. And chronic underdosing of animals in a herd may enhance development of resistance to ivermectin and other macrocyclic lactone in gastrointestinal roundworms.
To our knowledge similar studies have not been carried out with the eprinomectin pour-ons, but it must be assumed that the licking-behavior of cattle affects intake of eprinomectin in a comparable way. A similar effect of the licking behavior on the intake of active ingredient after pour-on administration has also been shown for fluazuron, a tick development inhibitor.
In contrast with the injectable formulations, the pour-on formulations should not be administered to wet animals, and rain shortly before (up to 6 hours) or after administration can cause product run-off and thus under-dosing. The pour-on shouldn't be administered by strong winds that may blow away part of the product and/or contaminate the workers.
For all these reasons efficacy after pour-on administration is usually less reliable than after injection.
A long-acting injectable formulation of eprinomectin is also available for cattle (LONGRANGE, not availably in all countries), but so far neither drenches for oral administration, nor products containing mixtures of eprinomectin with other active ingredients (e.g. against liver fluke) have been introduced in most countries.
The different withholding periods in various countries illustrate the fact that unfortunately, national regulatory authorities often draw different conclusions from exactly the same scientific evidence. This has been always so and there are no indications that things will improve in the near future.
Being an excellent antiparasitic, comparable to ivermectin, eprinomectin does not control all parasites of livestock. Unfortunately advertising and even the label of some generic formulations in less developed countries often include unsubstantiated claims. To help preventing confusion and misuse it is useful to know that whatever eprinomectin 0.5% pour-on formulation (without additional active ingredients) used at the recommended dose DOES NOT CONTROL:
- Most ticks (e.g. Amblyomma spp, Rhipicephalus spp, Dermacentor spp, Haemaphysalis spp, Hyalomma spp, Ixodes spp, etc.)
- Flies other than horn flies (e.g. houseflies, stable flies, black flies, horse flies, etc.)
- Fleas (e.g. Ctenocephalides spp)
- Tapeworms (e.g. Moniezia spp)
- Flukes (e.g. liver fluke Fasciola hepatica)
For an overview and a list of the most popular pour-ons for livestock click here.
This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics.
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