Anthelmintics features

Table 4.1 Phannacalogical and therapeutic features of equine anthelmintics... 

When colic is a clinical feature, administration of anthelmintics might exacerbate signs, and recent anthelmintic dosing is a known risk factor for the onset of overt cyathostomosis. 

In addition to the group of compounds discussed in the preceeding chapters, a few other classes of compounds have been found to exhibit promising anthelmintic activity and provide useful leads for exploration. The salient features of these promising compounds are presented in this chapter. 

Anthelmintics as a group share few common features of chemical similarity or mechanism of action. Table 7-10 lists many of the available drugs and the disease or organism against which they have been found useful. (Structures given elsewhere are not repeated.)... 

Praziquantel (PQ) (Table 7-10), a pyrazinoisoquinoline, can be viewed as having evolved from mirasan by optimizing structural features of compound V (Fig. 7-14). For all intents and purposes it is the first really broad-spectrum anthelmintic that is effective against all schistosomes and most other flukes, such as liver, intestinal, and lung (see Table 7-9 for species). PQ is rapidly becoming the drug of choice for many of the preceding infections, as well as for the cestodes (tapeworms). 

The herb Cleome viscosa (syn. cleome icosandra)y which is widely distributed in India, has long been recognized by the native population to serve as a rubefaciant, vesicant, and anthelmintic agent. As a consequence of these reputed properties, three research groups undertook almost simultaneously in the late 1970 s to determine the principal active constituent of this sticky, odoriferous plant [82,83]. On the basis of the NMR, X-ray, and CD data, the substance was determined to be the macrocyclic diterpene lactone 160 and named cleomeolide. The structural features of this macrolide are unusual in several respects (a) the double bond positioned a,p to the lactone carbonyl resides at a bridgehead site, a... 

Describe the main features of important back-up anthelmintics. 

The avermectins, which possess potent anthelmintic and insecticidal activities, have structural features similar to the milbemycins. The C-15 to C-28 spiroketal-containing unit (690) of avermectin Bia aglycone (691) is s)mthesized in optically pure form by coupling L-malic acid-derived lactone 687 with D-glucose-derived acetylene 688. Partial reduction of the... 

Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and fumes Uses Medicine (anthelmintic) perfumes cosmetic ingred. intermediate synthetic flavoring agent in foods and pharmaceuticals Features Sweet, cinnamon-like flavor Regulatory FDA 21CFR 172.515 FEMA GRAS Japan approved as flavoring BP compliance Manuf./Distrib. Aceto http //www.aceto.com. Advanced BioTech http //www.adv-bio.com,... 

---