Metalaxyl is a systemic fungicide used to control plant diseases caused by Oomycete fungi. Metalaxyl is a racemic mixture of two isomers, one of which, the R-enantiomer, is the active form. This enantiomer is the basis of the fungicide, metalaxyl-M (mefenoxam), which is effective at half the application rate of metalaxyl. This was developed by Syngenta as a replacement for metalaxyl, and was part of a strategy to stifle generic competition. Metalaxyl`s formulations include granules, wettable powders, dusts, and emulsifiable concentrates. Application may be by foliar or soil incorporation, surface spraying (broadcast or band), drenching, and seed treatment. Metalaxyl registered products either contain metalaxyl as the sole active ingredient or are combined with other active ingredients (e.g., captan, mancozeb, copper compounds, carboxin). Due to its broad-spectrum activity, metalaxyl is used world-wide on a variety of fruit and vegetable crops. Its effectiveness results from inhibition of uridine incorporation into RNA and specific inhibition of RNA polymerase-1. Metalaxyl has both curative and systemic properties. Its mammalian toxicity is classified as EPA toxicity class III and it is also relatively non-toxic to most nontarget arthropod and vertebrate species.

Oxamniquine is an anthelmintic with schistosomicidal activity against Schistosoma mansoni, but not against other Schistosoma spp. Oxamniquine is a potent single-dose agent for treatment of S. mansoni infection in man, and it causes worms to shift from the mesenteric veins to the liver, where the male worms are retained; the female worms return to the mesentery, but can no longer release eggs. Oxamniquine is a semisynthetic tetrahydroquinoline and possibly acts by DNA binding, resulting in contraction and paralysis of the worms and eventual detachment from terminal venules in the mesentry, and death. Its biochemical mechanisms are hypothesized to be related to an anticholinergic effect, which increases the parasite’s motility, as well as to synthesis inhibition of nucleic acids. Oxamniquine acts mainly on male worms, but also induces small changes on a small proportion of females. Like praziquantel, it promotes more severe damage of the dorsal tegument than of the ventral surface. The drug causes the male worms to shift from the mesenteric circulation to the liver, where the cellular host response causes its final elimination. The changes caused in the females are reversible and are due primarily to the discontinued male stimulation rather than the direct effect of oxamniquine