EFFICACY AGAINST PARASITES
Efficacy against a specific parasite depends on the delivery form and on the dose administered. National regulatory authorities determine whether a product is approved for a given indication, i.e. use on a particular host at a specific dose and against a specific parasite. Check the labels of the products available in your country.
Click here for general information on features and characteristics of PARASITICIDES.
Oral LD50, rat, acute*: 40-1500 mg/kg depending on the vehicle
Dermal LD50, rat, acute*: >5000 mg/kg
* These values refer to the active ingredient. Toxicity has to be determined for each formulation as well. Formulations are usually significantly less toxic than the active ingredients.
MRL (maximum residue limit) set for animal tissues (e.g. beef, mutton pork or chicken)*:
- CODEX: No
- EU: Yes (Annex IIIA, set to the limit of detection)
- USA: No
- AUS: No, not required
* This information is an indicator of the acceptance of an active ingredient by the most influential regulatory bodies for use on livestock. MRL's for animal tissues may be set also for agricultural pesticides that are not approved for use on animals but are used on commodities fed to animals. A MRL may be also set in the form of an IMPORT TOLERANCE for active ingredients not approved in a particular country but approved for imported animal commodities.
Withholding periods for meat, milk, eggs, etc. depend on delivery form, dose and national regulations. Check the product label in your country.
General safety information for antiparasitics is available in specific articles in this site (click to visit):
- General safety of antiparasitics for domestic animals
- General safety of antiparasitics for humans
- General safety of antiparasitics for the environment
Never use products for livestock on dogs and cats unless they are explicitly approved for both livestock and pets. Pets may not tolerate livestock formulations.
Never use agricultural or hygiene products with this or any other active ingredient on livestock or pets, even if there are veterinary products with this same active ingredient approved for use on animals. The formulations for agricultural or hygiene use are different and may be toxic for livestock or pets.
It is obvious that veterinary products are not intended for and should never be used on humans!!!
MARKETING & USAGE
Decade of introduction: ~1900
Introduced by: Traditional use
Patent: Expired (particular formulations may be still patent-protected)
Use in LIVESTOCK: Yes, scarce and declining
Use in HORSES: No
Use in DOGS and CATS: Yes, very scarce
Main delivery forms:
Use in human medicine: No
Use in public/domestic hygiene: Yes
Use in agriculture: Yes
Generics available: Yes
On livestock: NO
On pets: No
Rotenone is a natural compound extracted from the roots of Derris spp (native to Asia), Lonchocarpus spp. (native to South America) and other related plants. It is toxic to many insects and fish species. These properties of the natural extract were already known in the 17th century. Some indigenous populations in Asia and Latin America use the toxic effect on fish for fishing. They grind leaves or roots of the plants, throw the extract into the river, and collect the stunned fish downstream.
Acute oral rat toxicity (LD50) of rotenone is 40 to 1500 mg/kg, depending on the vehicle. This means that, although being natural it is moderately toxic to mammals, very much like many synthetic parasiticides, e.g. organophosphates. Rotenone breaks down quickly in the environment and therefore is not as problematic as many other pesticides.
Rotenone is especially toxic to fish. In fact, in several places it is allowed for the elimination of invasive fish species in rivers and lakes, which are subsequently restocked with indigenous species. Some indigenous populations in Asia and Latin America use this toxic effect on fish for fishing. They grind leaves or roots of the plants, throw the extract into the river, and collect the stunned fish downstream.
Nowadays rotenone's use in livestock is very scarce. It is available in a few countries in the form of concentrates for dipping or spraying and in ready-to-use pour-ons. For dogs and cats it is used in a few shampoos, soaps, sprays and the like.
However, usage is declining. Several studies seem to confirm a link between high exposure to rotenone and Parkinson's disease in humans. Rotenone products are being phased out in the USA.
Efficacy of rotenone
Rotenone is sufficiently effective against various lice and mites species of sheep, cattle, pig, poultry, dogs and cats. Efficacy against fleas, flies and ticks is usually insufficient, especially when compared with more modern synthetic active ingredients.
So far there are no reports on resistance of veterinary parasites to rotenone.
Pharmacokinetics of rotenone
Topically applied to livestock or pets, rotenone is poorly absorbed through the skin. On the skin of treated animals and also in the environment rotenone is quickly broken down by sunlight (photolysis). Consequently the residual effect of topical products is rather short (a few days) and re-treatments may be required for ensuring adequate control of various parasites.
Metabolism and behavior of absorbed rotenone are not completely elucidated. After oral administration rotenone is slow and incomplete. Following intravenous injection to rats, up to 97% of the administered dose was excreted through feces 2 to 3 days after dosing. Absorbed rotenone is quite effectively metabolized in the liver. Excretion is achieved mainly through feces.
Acute oral rat toxicity (LD50) of rotenone is ~40 to 1500 mg/kg, depending on the vehicle and the raw material used for determination. In any case, such values indicate that, although being a natural product, it is moderately toxic to mammals, very much like many synthetic parasiticides, e.g. organophosphates.
Mechanism of action of rotenone
At the molecular level, rotenone's mode of action consists in blocking the oxidative phosphorylation in the cell mitochondria, which disturbs the production of ATP, the cellular "fuel". This impairs the parasites motility and probably other processes as well.
This mechanism is not insect-specific but common to all living organisms.
Click here to view the list of all technical summaries of antiparasitic active ingredients in this site.