Brand: CLOMAX ORAL
DELIVERY FORM: «drench» for oral administration.
- Abamectin: 1.0 g/L (equivalent to 0.1%)
- Closantel: 50 g/L (equivalent to 5%)
- Selenium 0.5 g/L, 2.2 g/L Cobalt: without any anthelmintic efficacy
CHEMICAL CLASS of the active ingredient(s):
- Abamectin: macrocyclic lactone
- Closantel: salicylanilide
PARASITES CONTROLLED * (spectrum of activity)
* Country differences may apply: read the product label!
- Adult and immature gastrointestinal roundworms:
- Barber’s Pole Worm: Haemonchus contortus
- Small Brown Stomach Worm: Teladorsagia (Ostertagia) circumcincta & T. trifurcata
- Black Scour Worm: Trichostrongylus vitrinus, Trichostrongylus colubriformis
- Stomach Hair Worm: Trichostrongylus axei
- Small Intestinal Worm: Cooperia oncophora, C. punctata, C. surnabada
- Thin-Necked Intestinal Worm: Nematodirus spathiger
- Intestinal threadworm: Strongyloides papillosus
- Barber’s Pole Worm: Haemonchus contortus
- Lungworms: Dictyocaulus filaria
- Liver fluke: Fasciola hepatica
1 ml product per 5 kg bodyweight, equivalent to:
- 0.2 mg/kg abamectin
- 10 mg/kg closantel
Read the product label for further details on dosing
- LD50 (acute oral) in rats:
- Abamectin: 10 mg/kg (for the a.i.)
- Closantel: 262 to 342 mg/kg (for the a.i., depending on the studies)
Suspected poisoning? Read the articles on abamectin safety and closantel safety in this site.
Withholding periods (=withdrawal times) for meat & milk (country-specific differences may apply: read the product label)
- Meat: New Zealand 56 days
- Milk for human consumption: New Zealand: Milk intended for sale for human consumption must be discarded during treatment and for not less than 56 days following the last treatment.
WARNING !!!: Never use on humans, dogs or 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
Unfortunately, resistance of several gastrointestinal roundworms to abamectin (and other macrocyclic lactones) is already very high and very frequent worldwide in sheep and goats. Cases of multiple resistance (i.e. simultaneous) to two or more chemical classes have also been reported. Most affected worm species in sheeps are: Haemonchus spp, Ostertagia spp /Teladorsagia spp, Trichostrongylus spp, Nematodirus spp, Chabertia ovina.
There are reported cases of resistance of Haemonchus contortus and Fasciola hepatica to closantel, but so far they seem to remain rare in most countries.
This means that if this product does not achieve the expected efficacy against the mentioned parasites, it can be due to resistance and not to incorrect use, which is usually the most frequent cause of product failure.
It is generally accepted that the use of mixtures of active ingredients with different modes of action against a given parasite can delay the appearance of resistance. But only if the concerned parasites are susceptible to all the actives in the mixture. If not, the mixture is likely to promote multi-resistant parasites, because the selection pressure against all actives remains in place. Mixtures such as this one may provide peace-of mind to those users that do not know the resistance status of worms in their property: at least one of the actives will work... This may be the case for a while. But the risk that some worm species become resistant to all components after a few years using the same or comparable mixtures is considerable. If it is not too late, a better alternative is to determine the resistance status in the property and to rotate among products (not mixtures) against which the worms have not yet developed resistance, stopping the use of those chemical classes that have already shown resistance problems.
Alternative chemical classes/active ingredients to prevent resistance of gastrointestinal roundworms through product rotation:
- Benzimidazoles, e.g. albendazole, febantel, fenbendazole, oxfendazole, etc. Similar or even worse resistance problems than macrocyclic lactones.
- Derquantel: available so far only for sheep in combination with abamectin.
- Monepantel: available only for sheep & goats in some countries (e.g. Australia, UK & EU, New Zealand). First cases of resistance reported in New Zealand in 2013.
- Levamisole. Resistance to levamisole has been reported in most countries, but is usually less strong and frequent than to benzimidazoles.
- Tetrahydropyrimidines (e.g. morantel, pyrantel): effective only against certain gastrointestinal roundworms. Not available in some countries. Resistance to morantel has been reported in some countries.
- Nitroxinil: effective only against certain gastrointestinal roundworms (e.g. Bunostomum spp, Haemonchus spp, Oesophagostomum spp). Not available in some countries.
These alternative products may not be available in all countries, or may not be available as drenches, or may not be effective against all the concerned parasites.
It is highly recommended to periodically check the resistance status of each property performing appropriate tests (e.g. fecal egg counts) under supervision of a veterinary doctor. Such tests are now routinely available for most producers in developed countries.
Learn more about resistance and how it develops.
Are the active ingredients of this product ORIGINAL* or GENERICS**?
- Abamectin: GENERIC (introduced in the 1980s)
- Closantel: GENERIC (introduced in the 1970s)
*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: New Zealand
GENERIC BRANDS available? Yes, in Australia and/or New Zealand, not elsewhere. This product itself contains generic active ingredients.
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used drench brands for livestock click here.
CLOMAX ORAL is a drench brand from NEXAN combining 2 active ingredients with different modes of action against gastrointestinal roundworms of sheep: abamectin and closantel.
Abamectin, one of the first macrocyclic lactones developed, was introduced already in the 1980s (by MSD AGVET). As all macrocyclic lactones, abamectin is an endectocide, i.e. it is simultaneously effective against some external parasites and against internal parasites (mainly roundworms). As for other macrocyclic lactones, abamectin has no efficacy whatsoever against tapeworms and flukes. Abamectin is considered as the "cheap" ivermectin, with a similar spectrum of efficacy but less potent and slightly more toxic. It is abundantly used in ruminants, much less in pig, poultry and pets. Abamectin is also used in agricultural and hygiene pesticides worldwide. Interestingly abamectin is widely used on livestock in Australia and New Zealand but insignificantly in the EU, the USA and Canada.
Closantel is a veteran flukicide (introduced in the 1970s by JANSSEN) but a rather particular one, because it is effectiev against liver flukes, against a few roundworms and against a few external parasites as well (e.g. nasal bots). Closantel offers good control of adult liver flukes, but efficacy against immatures is incomplete (>5 weeks ~90%; 3-4 weeks <73%): this is important because immature stages are the most damaging ones. Efficacy against roundworms is usually limited to blood-feeding species. This is related to the fact that ingested closantel is quickly absorbed to blood where it binds strongly to plasma proteins. There it remains for several days before being excreted. In contrast, its concentration in the tissues is usually too low to kill worms that do not feed blood, which are the majority among the roundworms that infect sheep.
In ruminants, reducing the amount of feed slows down the exit flow of the rumen and prolongs the time during which the active ingredient remains there and is absorbed. Consequently it is advisable to reduce the access of animals to feed (especially to fresh pasture, not to water) 24 hours before administration. For the same reason, it is better to keep the animals away from food for about 6 hours after drenching. However sick or weak animals should not be kept away from food and fasting animals should have access to water.
Thoroughly shaking suspensions before use is crucial for efficacy. If the active ingredient remains in the sediment, a few animals may get most of the active ingredient and will be overdosed, and the large majority will get almost only solvents and will be underdosed.
Click here for general information on good practices for the prevention and control of gastrointestinal worms in livestock.
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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