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Content Update
February 6, 2025
A Promising and Novel Agent for Treating Fluroquinolones-resistant Gonorrhea: Spiropyrimidinetriones (zoliflodacin): Spiropyrimidinetriones are a novel antimicrobial class in development that targets bacterial topoisomerases with mechanisms similar to but distinct from that of fluoroquinolones. The most advanced agent in the class, zoliflodacin, has shown potential as a first-line therapy for gonorrhea, especially in areas where resistance to standard therapies is high. The development of zoliflodacin is the result of a partnership between a nonprofit group (Global Antibiotic Research and Development Partnership, GARDP) and a commercial pharmaceutical company.
Zoliflodacin
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Abbreviations
AIDS: acquired immunodeficiency syndrome
CSF: cerebrospinal fluid
DHFR: dihydrofolate reductase
GI: gastrointestinal
HIV: human immunodeficiency virus
PABA: para-aminobenzoic acid
TMP: trimethoprim
SMX: sulfamethoxazole
UTI: urinary tract infection
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HISTORICAL PERSPECTIVE
The sulfonamide drugs were the first effective chemotherapeutic agents used systemically for the prevention and cure of bacterial infections in humans. Investigations in 1932 at the I. G. Farbenindustrie in Germany resulted in the patenting of prontosil and several other azo dyes containing a sulfonamide group. Because synthetic azo dyes had been studied for their action against streptococci, Domagk tested the new compounds and observed that mice with streptococcal and other infections could be protected by prontosil. In 1933, Foerster reported giving prontosil to a 10-month-old infant with staphylococcal septicemia and achieving a dramatic cure. Favorable clinical results with prontosil and its active metabolite, sulfanilamide, in puerperal sepsis and meningococcal infections awakened the medical profession to the new field of antibacterial chemotherapy, and experimental and clinical articles soon appeared in profusion. The development of the carbonic anhydrase inhibitor–type diuretics and the sulfonylurea hypoglycemic agents followed from observations made with the sulfonamide antibiotics. For discovering the chemotherapeutic value of prontosil, Domagk was awarded the Nobel Prize in Medicine for 1938 (Lesch, 2007). The advent of penicillin and other antibiotics diminished the usefulness of the sulfonamides, but the introduction of the combination of trimethoprim (TMP) and sulfamethoxazole (SMX) in the 1970s increased the use of sulfonamides for the prophylaxis and treatment of infections.
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Sulfonamides are derivatives of para-aminobenzenesulfonamide (sulfanilamide; Figure 57–1) and are congeners of para-aminobenzoic acid (PABA). Most of them are relatively insoluble in water, but their sodium salts are readily soluble. The minimal structural prerequisites for antibacterial action are all embodied in sulfanilamide itself. The sulfur must be linked directly to the benzene ring. The para-NH2 group (the N of which has been designated as N4) is essential and can be replaced only by moieties that can be converted in vivo to a free amino group. Substitutions made in the amide NH2 group (position N1) have variable effects on antibacterial activity of the molecule; substitution of heterocyclic aromatic nuclei at N1 yields highly potent compounds. The sulfone agent dapsone is discussed in Chapter 65.
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