Macrocyclic lactone ivermectin

Macrocyclic lactones Ivermectin p.o. 0.2 Affect glutamategated chloride ion channels 6-8 / — - ... 

Ivermectin, a macrocyclic lactone, is also utilized to control parasites. An immunoassay was developed to determine ivermectin residues in bovine liver by Crooks etal. The sample preparation procedure was complex, involving tissue homogenization in acetonitrile, centrifugation, extraction with hexane (to remove lipids), evaporation and reconstitution in ethyl acetate, and passage through an SPE column followed... 

The microorganism was classified as a new species of actinomycete. Streptomyces avermitilis. Its anthelmintic activity was shown to reside in 8 closely related macrocyclic lactones, named avermectins, which were also found to possess activity against free-living and parasitic arthropods. One of the natural components, avermectin is now being evaluated as a pesticide for the control of mites of citrus and cotton crops and control of the Red Imported Fire Ant. A chemical derivative, 22,23-dihydroavermectin or ivermectin, has been developed as an antiparasitic agent. It is being marketed for use in cattle, horses and sheep and is expected to become available for swine and dogs. 

Ivermectin, a semisynthetic macrocyclic lactone, is a mixture of avermectin Bia and avermectin Bib. It... 

Ivermectin (9.119), a semisynthetic macrocyclic lactone, is the dmg of choice for strongyloidiasis and onchocerciasis types of helminth infestation. Ivermectin appears to paralyze the nematode, which may lead to its death but which certainly facilitates its expulsion from the body. 

Ivermectin Bia Synthetic Macrocyclic lactone C48H74O14 874 238, 245 Methyl ethyl... 

Included in the class of macrocyclic lactones are avermectins and milbemycins, which are fermentation products possessing a 16-member cyclic lactone, a spiroketal moiety, and a disaccharide unit. Abamycin, ivermectin, doramectin, and eprinomycin are the avermectins most often available for anthelminthic treatment of livestock, whereas moxidectin is a milbemycin with worldwide acclaim as a cattle anthelminthic. Other anthelminthics currently used in food-producing animals are clorsulon, which is a benzenesulphonamide derivative praziquantel, which is a racemate derivative of pyrazino-isoquinoline and hygromycin B, which is an aminoglycoside antibiotic that exhibits anthelminthic properties. 

Ivermectin possesses a broad spectrum of antiparasitic activities [51] and is a 22,23-dihydro analogue of the macrocyclic lactone, avermectin B,. Ivermectin is highly effective against microfilariae of O. volvulus at very low doses (50-200/ig/kg) [52] and in comparison with DEC, induces only mild mazzotti reactions and other side-effects. Its effectiveness against D. viteae in M. natalenis [38] and D. immitis [53] is also documented. 

Avermectins (113, 114) are a series of macrocyclic lactones that are broad-spectrum, highly potent, glutamate-gated, chloride chaimel-modulator antiparasitic agents produced by Strep-tomyces avermitilis (146, 147). Ivermectin, 23,24-dihydroaver-mectin (115), was the first product approved in the... 

There are five macrocyclic lactones utilized in veterinary practice of which ivermectin (an aver-mectin) and moxidectin (a milbemycin) are approved for use in the horse. Ivermectin and moxidectin selectively paralyze parasites by increasing muscle chloride permeability through interaction with glutamate-gated chloride ion channels (McKellar Benchaoui 1996). There is evidence that ivermectin and moxidectin may have several sites of action within the parasite and the effects of these compounds may also differ between the nematode species (McKellar Benchaoui 1996, Martin 1997). 

Macrocyclic lactones are highly lipophilic and are distributed widely to and eliminated slowly from the body compartments such that they have persistent anthelmintic activity. There are physicochemical differences between ivermectin and moxidectin that confers different lipid solubility on each drug moxidectin has a much longer half-life in body fat (Afzal et al 1997). This constitutes at least a partial explanation for the longer period of suppression of equine fecal worm egg output achieved following dosing with moxidectin compared with ivermectin (Jacob et al 1995,... 

The macrocyclic lactones (p. 64) are less effective against ectoparasites in the horse than in ruminants, but extra-label use of the injectable solution of ivermectin for cattle applied topically to... 

Extracted from the soil actinomycete Streptomyces avermitilis, the natural avermectins are 16-membered macrocyclic lactones that, on reduction of the C22-23 double bond, give rise to ivermectin (IVM), which is an 80 20 mixture of dihydroavermectin Bia and Bip, respectively. The natural avermectins have minimal biological activity, but IVM has proven to be quite beneficial in the treatment of various nematode infections. 

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