Brand: VETMED COMBOMAX
DELIVERY FORM: «drench» for oral administration.
- Oxfendazole 45.3 g/L (equivalent to 4.53%)
- Levamisole hydrochloride 80 g/L (equivalent to 8.0%; corresponds to 69 g/L LEVAMISOLE)
- Cobalt 0.4 mg/mL, Zinc 1.2 mg/mL and Selenium 1mg/mL: without anthelmintic efficacy
CHEMICAL CLASS of the active ingredient(s):
- Oxfendazole: benzimidazole
- Levamisol: imidazothiazole
INDICATIONS: CATTLE & SHEEP
PARASITES CONTROLLED (spectrum of activity)
- Adult and immature gastrointestinal roundworms:
- Barber’s Pole Worm: Haemonchus contortus
- Small Brown Stomach Worm: Ostertagia circumcincta
- Black Scour Worm: Trichostrongylus colubriformis, T. vitrinus
- Stomach Hair Worm: Trichostrongylus axei
- Small Intestinal Worm: Cooperia curticei
- Thin-Necked Intestinal Worm: Nematodirus filicollis, N. spathiger, N. abnormalis
- Hookworm: Bunostomum trigonocephalum
- Large Mouthed Bowel Worm: Chabertia ovina
- Nodule Worm: Oesophagostomum columbianum
- Large Bowel Worm: Oesophagostomum venulosum
- Lungworm: Dictyocaulus filaria
- Tapeworms: Moniezia spp
- Adult and immature gastrointestinal roundworms:
- Small Brown Stomach Worm: Ostertagia ostertagi, O. leptospicularis
- Black Scour Worm: Trichostrongylus longispicularis
- Stomach Hair Wor: Trichostrongylus axei
- Small Intestinal Worm: Cooperia oncophora, C. punctata
- Thin-Necked Intestinal Worm: Nematodirus helvetianus
- Hookworm: Bunostomum phlebotomum
- Large Bowel Worm: Oesophagostomum radiatum
- Capillaria bovis
- Lungworm: Dictyocaulus viviparus
- Tapeworms: Moniezia spp
* Country-specific differences may apply: read the product label.
1 mL product per 10 kg bodyweight, equivalent to:
- 4.5 mg/kg oxfendazole
- 8 mg/kg levamisole hydrochloride (6.9 mg levamisole)
- LD50 (acute oral) in rats:
- Oxfendazole: >6400 mg/kg (for the a.i.)
- Levamisole: 180 mg/kg (for the a.i.)
Suspected poisoning? Read the articles on oxfendazole safety and levamisole safety in this site.
Withholding periods (=withdrawal times) for meat & milk (country-specific differences may apply: read the product label)
- Meat: New Zealand; Cattle & Sheep 14 days
- Milk for human consumption: New Zealand: Cattle 144 hours; Sheep 25 days
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 oxfendazole (and other benzimidazoles) and levamisole is already very high and very frequent worldwide in sheep and goats, less in cattle. Cases of multiple resistance (i.e. simultaneous) to two or even three chemical classes have also been reported. Most affected worm species are:
- Sheep: Haemonchus spp, Ostertagia spp /Teladorsagia spp, Trichostrongylus spp, Nematodirus spp, Chabertia ovina
- Cattle: Cooperia spp, Ostertagia spp, Haemonchus spp, Trichostrongylus spp, Oesophagostomum spp.
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 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 may 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:
- Derquantel: available so far only for sheep in combination with abamectin.
- Macrocyclic lactones (e.g. abamectin, doramectin, eprinomectin, ivermectin, moxidectin, etc.). Resistance to macrocyclic lactones is also increasing and strengthening quickly in many countries.
- 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.
- Salicylanilides (e.g. closantel): effective only against certain gastrointestinal roundworms. Not available in some countries. Resistance to closantel has been reported in some countries.
- 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**?
- Oxfendazole: GENERIC (introduced in the 1970s)
- Levamisole: GENERIC (introduced in the 1960s)
*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 & New Zealand, not elsewhere; perhaps with a slightly different composition.
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used drench brands for livestock click here.
VETMED COMBOMAX is a drench brand from NEXAN combining 2 generic active ingredients with different modes of action against gastrointestinal worms of sheep: oxfendazole and levamisole hydrochloride.
Oxfendazole is a veteran benzimidazole introduced in the 1970s (by WELLCOME, SYNTEX). It has a broad-spectrum of activity against roundworms (gastrointestinal and pulmonary) and tapeworms (dose-dependent) but is ineffective against flukes. Oxfendazole also kills eggs of roundworms (ovicidal activity). As all benzimidazoles, oxfendazole has no efficacy whatsoever against external parasites (ticks, flies, lice, mites, etc). Among the benzimidazoles oxfendazole is quite comparable with fenbendazole in terms of efficacy and safety. It is moderately used in livestock and horses, rather scarcely in pets, and not at all in agriculture.
Levamisole is the most veteran anthelmintic in this combination. It was introduced by JANSSEN already in the 1960s (NILVERM, RIPERCOL). It has a broad-spectrum of activity against roundworms (gastrointestinal and pulmonary) but no efficacy whatsoever against tapeworms and flukes. It is also completely ineffective against external parasites of livestock (ticks, flies, lice, mites, etc). Levamisole has been used massively worldwide in countless generic formulations. It still remains one of the most preferred low-cost anthelmintics for livestock worldwide.
Oxfendazole and levamisole administered as a drench have no residual effect, i.e. they kill the parasites shortly after administration, but do not significantly protect the animals against re-infestation by infective stages in their environment. Whether such protection can be ensured by abamectin depends on the resistance status of the concerned worm species.
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.
Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.
In case of doubt contact the manufacturer or a veterinary professional.