Biological Sciences
Nystatin
Nystatin is an antifungal medication used to treat fungal infections, particularly those caused by Candida species. It works by binding to the fungal cell membrane, disrupting its structure and allowing leakage of cellular contents, ultimately leading to the death of the fungus. Nystatin is commonly used to treat oral thrush, vaginal yeast infections, and certain types of diaper rash.
Written by Perlego with AI-assistance
Related key terms
1 of 5
3 Key excerpts on "Nystatin"
eBook - PDF- G. E. W. Wolstenholme, Ruth Porter, G. E. W. Wolstenholme, Ruth Porter(Authors)
- 2009(Publication Date)
- Wiley(Publisher)
Several reports deal with general aspects of anti- fungal agents (Byrde and Ainsworth, 1958; Drouhet, 1957, 19580, 1961, 1963 ; Hildick-Smith, Blank and Sarkany, 1964; Waksman and Lechevalier, 1962; Waksman, Lechevalier and Schaffner, 1965). I will now present only a few biological data concerning the tolerance, absorption and distribution in tissues and body fluids of polyene antibiotics in order to support the clinical data reported by Utz and co-workers (1967) on the therapeutic activities of these antibiotics on the deep mycoses. Oral administration Polyelie antibiotics can usually be tolerated orally in relatively largc doses. Nystatin (a tetraene) is remarkably non-toxic in doses of 4-8 g. (8-16 x 106 units). This lack of toxicity is due to poor absorption through the gastro- intestinal tract. Initial blood level studies showed poor absorption (0.9 to I- I units/ml. of plasma), but subsequent data failed to confirm thse findings. Thirty-two per cent of orally administered Nystatin is recovered from the faeces, and less than I per cent from the urine, in 24 hours. These data explain the effectiveness of Nystatin in experimental and human candida infections of the alimentary tract, and its ineffectiveness in both experimcntal and human deep mycoses. Nystatin as a powder or a crushed A N T I F U N G A L A N T I B I O T I C S : B I O L O G I C A L A C T I V I T Y 223 tablet is the most suitable formulation for adequate local contact of anti- biotic from the mouth and throughout the gastro-intestinal tract affected with candidosis. The notion ofNystatin as a contact antibioticis essential for understanding its activity in vivo. Even though Nystatin is not absorbed into the bloodstream, it is effective in some cases of systemic candidosis because it sterilizes the intestinal focus responsible for the dissemination of Candida (Drouhet, I~SSU, b). Pimaricin, a thermostable tetraene discovered by Struyk and co-workers (1958), has an L D ~ ~ of 1,500 mg./kg.
- John S. Bradley, John D. Nelson, John S. Bradley, John D. Nelson(Authors)
- 2024(Publication Date)
- American Academy of Pediatrics(Publisher)
This chapter focuses on only the most commonly used systemic agents and does not highlight the many anticipated new agents until they are approved for use in patients. For each agent, there are sometimes several formulations, each with unique pharmacokinetics (PK) that one must understand to optimize the agent, particularly in patients who are critically ill. Therefore, it is more important than ever to establish a firm conceptual foundation in understanding both how these antifungal agents work to optimize PK and pharmacodynamics (PD) and where they work best to target fungal pathogens most appropriately. Polyenes Amphotericin B (AmB) is a polyene antifungal antibiotic that has been available since 1958. A Streptomyces species, isolated from the soil in Venezuela, produced 2 antifungals whose names originated from the drug’s amphoteric property of reacting as an acid as well as a base. Amphotericin A was not as active as AmB, so only AmB is used clinically. Nystatin is another polyene antifungal, but, due to systemic toxicity, it is used only in topical preparations. Nystatin was named after the New York State Department of Health, where the discoverers were working at the time. AmB remains the most broad-spectrum antifungal available for clinical use. This lipophilic drug binds to ergosterol, the major sterol in the fungal cell membrane, and for years it was thought to create transmembrane pores that compromise the integrity of the cell membrane and create a rapid fungicidal effect through osmotic lysis. However, new biochemical studies suggest a mechanism of action more related to inhibiting ergosterol synthesis. Toxicity is likely due to cross- reactivity with the human cholesterol bi-lipid membrane, which resembles fungal ergosterol. The toxicity of the conventional formulation, amphotericin B deoxycholate (AmB-D)—the parent molecule coupled with an ionic detergent for clinical use—can
- John S. Bradley, John D. Nelson, John S. Bradley, John D. Nelson(Authors)
- 2022(Publication Date)
- American Academy of Pediatrics(Publisher)
Therefore, it is more important than ever to establish a firm conceptual foundation in understanding how these antifungal agents work to optimize pharmacokinetics and also where they work best to target fungal pathogens most appropriately. Polyenes Amphotericin B (AmB) is a polyene antifungal antibiotic that has been available since 1958. A Streptomyces species, isolated from the soil in Venezuela, produced 2 antifungals whose names originated from the drug’s amphoteric property of reacting as an acid as well as a base. Amphotericin A was not as active as AmB, so only AmB is used clinically. Nystatin is another polyene antifungal, but, due to systemic toxicity, it is used only in topical preparations. Nystatin was named after the New York State Department of Health, where the discoverers were working at the time. AmB remains the most broad-spectrum antifungal available for clinical use. This lipophilic drug binds to ergosterol, the major sterol in the fungal cell membrane, and for years it was thought to create transmembrane pores that compromise the integrity of the cell membrane and create a rapid fungicidal effect through osmotic lysis. However, new biochemical studies suggest a mechanism of action more related to inhibiting ergosterol synthesis. Toxicity is likely due to cross- reactivity with the human cholesterol bi-lipid membrane, which resembles fungal ergosterol. The toxicity of the conventional formulation, AmB deoxycholate (AmB-D)— the parent molecule coupled with an ionic detergent for clinical use—can be substantial from the standpoints of systemic reactions (eg, fever, rigors) and acute and chronic renal toxicity. Premedication with acetaminophen, diphenhydramine, and meperidine has 164 — Chapter 6. Choosing Among Antifungal Agents Choosing Among Antifungal Agents 6 historically been used to prevent systemic reactions during infusion.
Index pages curate the most relevant extracts from our library of academic textbooks. They’ve been created using an in-house natural language model (NLM), each adding context and meaning to key research topics.
