Sulphonamides and Sulphones

Abstract

Certain amount of confusion often arises between the two classes of drugs, the Sulphonamides and the Sulphones. The question often arises amongst the medical men, ' what are the

Mechanisms of Resistance of Malaria Parasites to Antifolates

“…Several early trials confirmed that a single 1-g dose of sulfadoxine was an effective, although slow, schizontocide. Although in vivo resistance to sulfonamides and sulfones could be demonstrated with relative ease in animal models (Scholer et al, 1984), in vivo human field studies continued to offer encouragement. For example, weekly sulfadoxine (500 mg) prophylaxis resulted in no positive blood smears at the end of 6 weeks compared with a 26% positive rate with pyrimethamine prophylaxis (Laing, 1964).…”

“…Likewise, DHFR/DHPS inhibitors are less active against both P. malariae and P. ovale than is chloroquine. The antifolates have had mixed clinical success in these latter species (Archibald, 1951;Young, 1957;Hurly, 1959;Clyde, 1967b;Laing, 1968b;Michel, 1968; quoted by Scholer et al, 1984). P. falciparum is inherently more sensitive to the effects of DHFR/ DHPS inhibitors, has well described molecular markers for drug resistance, and will therefore be the focus of the rest of this review.…”

Enhancing Hatch Rate and Survival in Laboratory‐Reared Hybrid Devils Hole Pupfish through Application of Antibiotics to Eggs and Larvae

“…Antibiotics.-Antibiotics were prepared by two-step dilution from stocks to obtain the following treatment concentrations: CAM, 50 mg/L (EMD Chemicals, Gibbstown, New Jersey); ERY, 12.5 mg/L (EMD Chemicals); TMP-SMX, 25 mg/L (Thomas Laboratories, Tolleson, Arizona); and CEX, 6.6 mg/L (Thomas Laboratories). These dosages were based on manufacturer recommendations due to limited experimental data in the case of CEX (Scholer et al 1984) or based on previously reported concentrations (CAM, ERY, and TMP-SMX) that had proven effective in chemoprophylaxis or as chemotherapeutics in a variety of fish or bacteria species (Austin 1985;Lewbart 1991;Vaseeharan et al 2005). Some dosages were previously reported as therapeutic in intravenous or feed-delivered administration.…”

“…Both compounds are inhibitors of tetrahydrofolate biosynthesis at different active sites. Individually, each compound is bacteriostatic, but in combination they are bactericidal against a very broad spectrum of bacteria (McCarthy et al 1974;Scholer et al 1984;Heaslet et al 2009). Potentiated sulfonamides are approved for application in U.S. aquaculture in the form of sulfadimethoxine/ormetoprim.…”