Influence sulfonamides

Both age and diet may influence sulfonamide absorption in calves. Oral absorption of sulfadiazine was very slow in calves on milk diets, and bioavailability was greater in ruminating than milk-fed pre-ruminant calves. Trimethoprim, on the other hand, was well absorbed in preruminant calves but not in ruminating animals, possibly as a result of inactivation by ruminal microflora. 

Sulfonamides. A/-Halo-A/-alkylsulfonamides, RS02NR X, are relatively stable distillable Hquids. Under the influence of uvlight they form 1 1 adducts with olefins (67,100). Ai-/-Butyl derivatives rearrange forming precursors to cyclopropanes and sultams. A/-Halo-A/-sodioalk5lsulfonamidates, RS02NClNa, have been less extensively studied than their aromatic counterparts (70). The stabiHty of these compounds approaches that of the aromatic sulfonamides (80). The dodecyl compound exhibits properties of both a disinfectant and a surfactant. 

It was found, furthermore, that the substituent on the sulfonamide group of the chiral hgand strongly influenced the enantiofacial selectivity. Hence, ligand 81 bearing a tosyl substituent delivered the endo-(2il)-cycloadduct, whereas a trifluoromethanesulfonamide group afforded its enantiomer. The authors proposed that the latter substituent should increase the Lewis acid-... 

CW Conroy, RH Buck. (1992). Influence of ion pairing salts on the transcomeal permeability of ionized sulfonamides. J Ocular Pharmacol 8 233-240. 

Antibacterial sulfonamides contain two N-atoms, the sulfonamido (N1) and the para primary amino (N4). The sulfonamido group, in contrast to a carboxamido group, is chemically and metabolically stable. In other words, hydrolytic cleavage of sulfonamides to produce a sulfonic acid and an amine has never been observed. We, therefore, focus our discussion on the primary amino group, acetylation of which is one of the major metabolic pathways for some sulfonamides. Hydrolysis of the N4-acety luted metabolites back to the parent sulfonamide can occur in the liver, kidney, and intestinal tract. The reaction is strongly influenced by the structure of the parent amine e.g., N4-acetylsulfisoxazole (4.121) was deacetylated by intestinal bacteria whereas /V4-acctyIsulI anilamide (4.122) under identical conditions was not [78][79],... 

CE Lin, WC Lin, WC Chiou, EC Lin, CC Chang. Migration behavior and separation of sulfonamides in capillary zone electrophoresis. I. Influence of buffer pH and electrolyte modifier. J Chromatogr A 755 261-269, 1996. 

Probenecid can impair the renal active secretion of a variety of acidic compounds, including sulfinpyrazone, sulfonylureas, indomethacin, penicillin, sulfonamides, and 17-ketosteroids. If these agents are to be given concomitantly with probenecid, their dosage should be modified appropriately. Salicylates interfere with the clinical effects of both sulfinpyrazone and probenecid and should be avoided in patients treated with uricosuric agents. Uricosuric agents also can influence the volume of distribution and hepatic metabolism of a number of drugs. 

However, the redox potentials of the Ni(II) complexes of the aza-cyclam (3b-3g) containing carboxamide or sulfonamide functional groups are reported to be influenced by the nature of the functional group. In particular, the amide fragment controls the reduction potential for the Nim/Nin and NiI1/NiI redox couples, which may be attributed to the it interaction between the nickel ion and the amido group 14). 

In addition, the solubilized sulfonamides as a group diffuse very widely into the tissues, penetrating into all fluids, including urine, bile, and milk. The degree of tissue penetration is influenced by several factors, including the ionization state and lipophilicity of the particular sulfonamide, the vascularity of the absorption site, and the degree of protein binding. 

The serum-protein binding ability, which varies between animals and is also influenced by the disease state of the animal, will also determine the free diffusible concentration. This, in turn, will have an effect on the elimination of drug residues as well as on their penetration in eggs or milk. This effect will be more pronounced for drugs with a higher tendency for protein binding such as sulfonamides, doxycycline, and cloxacillin (47). 

Apart from the pathophysiological condition of the animal, the mode of drug application may also significantly influence the pharmacokinetic profile of a drug (48, 49). For example, drug residues may persist at the injection site for prolonged periods of time (2). In a study in which various sulfonamides and trimethoprim were injected intramuscularly into swine, detectable residues were found at most sites 6 days after the injection, and with the sulfonamides at 30 days in almost half of the animals (50). Other drugs such as dihydrostreptomycin persist for up to 60 days, while positive residues of chloramphenicol are found at 7 days postinjection. Sodium and procaine penicillin, neomycin, tylosin, and oxytetracycline residues have also been determined at 24 h or more postinjection (51). 

The presence of the additional p-carbon atom in Tau analogues offers the opportunity to study the influence of functionalization at this p-position as compared to functionalization at the a-position. Naturally occurring a-amino acids can be used as starting materials for the synthesis of homochiral P-substituted methylene sulfinamide and sulfonamide transition-state isosteres incorporated in peptides.11201... 

This strongly supports the assumption of pore diffusion being a limiting factor for sulfonamides with a MW of > 300. The activity, on the other hand, depends only on the steric influence of the o-substituents of the 5-sulfanilamido-l-phenylpyrazoles. The regression coefficient with MR0 in the two derived equations is constant in both systems and accounts for the negative steric effect of the o-substituents for the interaction with the active site at the synthase. 

NMR studies showed that barriers to rotation exist for 3-dialkyl-aminobenz[d]isothiazole-1,1-dioxides their numerical values, coalescence temperatures, etc., are, however, dependenton the sol vent system.14 From frequency shifts in t.he infrared it is known that vibrations of S-0 bonds15 in sulfonamides, particularly those attributed to antisymmetric (v3) vibrations16 are susceptible to solvent influences. 

Because carbonic anhydrase inhibitors are sulfonamide derivatives, the mechanism for carbonic anhydrase inhibitor-induced myopia is expected to be similar to that associated with sulfonamides. Indeed, it has been speculated that myopia resulting from acetazolamide use is due to a hypersensitivity reaction that leads to ciliary body edema. The instillation of cycloplegics has little influence on the refractive error, which suggests that the mechanism is unrelated to ciliary spasm. 

Carbanions of a-haloalkyl aryl sulfones, sulfonates and sulfonamides react with quinoxalines according to two general pathways vicarious nucleophilic substitution of hydrogen and/or bis-annulation to bis(azirino)quinoxaline derivatives. The charge distribution in the anionic (T-adducts and reaction conditions influence the direction of these reactions. ... 

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