The influence of food on the pharmacokinetics of the triazole antimycotics fluconazole and itraconazole was investigated in a randomised, parallel group, single dose study in 24 healthy subjects. Each group took either a 100 mg capsule of fluconazole or a 100 mg capsule of itraconazole, pre-prandially or after a light meal or a full meal, in a three-way crossover design. Gastric and intestinal pH were measured with a co-administered radiotelemetric pH capsule, and gastric emptying time of the capsule (GET) was taken as the maximum gastric residence time of drug and food. The plasma AUC and Cmax of itraconazole were significantly different under the various conditions and the mean AUC was greatest after the full meal. The bioavailability (90% confidence intervals) of itraconazole relative to that after the full meal, was 54% (41-77%) on an empty stomach and 86% (65-102%) after a light meal. The criteria for bioequivalence were not attained. In contrast, the bioavailability (90% CI) of fluconazole relative to the full meal was 110% pre-prandially (100-115%) and 102% after the light meal (88-103%), and the criteria for bioequivalence were attained. Itraconazole absorption was promoted by low stomach pH, long gastric retention time and a high fat content of the coadministered meal, whereas the pharmacokinetics of fluconazole was relatively insensitive to physiological changes in the gastrointestinal tract.
The in vitro activity of voriconazole (UK-109, 496), a new antifungal triazole derivative, against 650 clinical isolates of yeasts, moulds and dermatophytes was compared with that of itraconazole, ketoconazole, amphotericin B and griseofulvin. The geometric means of the minimum inhibitory concentrations (MICs) of voriconazole were 0.05 microgram ml-1 against yeasts (n = 187), 0.58 microgram ml-1 against moulds (n = 260) and 0.08 microgram ml-1 against dermatophytes (n = 203). The overall activity of voriconazole against yeasts and moulds was good, being similar to that of itraconazole, ketoconazole and amphotericin B. Voriconazole was highly effective against Aspergillus fumigatus (mean MIC 0.23 microgram ml-1) and other Aspergillus species and showed noteworthy activity (mean MICs 0.08-0.78 microgram ml-1) against emerging and less common clinical isolates of opportunistic moulds, such as Alternaria spp., Cladosporium spp., Acremonium spp., Chrysosporium spp. and Fusarium spp. On the other hand, voriconazole was less active in vitro than the comparative agents studied against various species of zygomycetes, such as Mucor spp., Rhizopus spp. and Absidia spp. Voriconazole and the other two azoles, itraconazole and ketoconazole, were more active than griseofulvin in vitro against most dermatophytes tested.
The concentrations of azithromycin in polymorphonuclear leukocytes (PMNLs), monocytes, erythrocytes, and plasma were measured in six healthy volunteers after the last treatment of a 3-day regimen of 500 mg once daily. Marked enrichment of azithromycin was found in PMNLs and monocytes. The drug concentrations after the last dose amounted to 114 +/- 43 (mean +/- standard deviation) mg/liter at 12 h in PMNLs and 34 +/- 17 mg/liter at 6 h in monocytes. Fourteen days thereafter, azithromycin was still detectable in the PMNLs at 53 +/- 34 mg/liter and in the monocytes at 1 +/- 2 mg/liter, although the drug was no longer detectable in plasma (< 0.02 mg/liter). Maximum drug concentrations for azithromycin in plasma (0.40 +/- 0.30 mg/liter) and erythrocytes (0.15 +/- 0.05 mg/liter) at 3 h after the last administration were much lower and occurred earlier than those observed in the phagocytic cells. The mean enrichment factors (cellular/extracellular ratios) of azithromycin in phagocytes relative to plasma came to 231 +/- 150 and 3,924 +/- 584 at 3 and 120 h, respectively, for PMNLs and 83 +/- 55 and 523 +/- 285 at 3 and 120 h for monocytes, respectively, after the last dose. The phagocytosis tests with PMNLs separated from the blood of volunteers at various times after the last treatment confirmed the enhanced intracellular activity of these cells against staphylococci.
Summary. Fluconazole is an antimycotic drug which until now has been used mostly in the systemic therapy of yeast infections. We have now demonstrated the presence of this drug in various skin structures. After administration of 50 mg of fluconazole per day for 12 days to healthy volunteers, the following mean drug concentrations were measured: serum 1.81 μg ml‐1, sweat 4.58 μg ml‐1, dermis‐epidermis (without stratum corneum) 2.77 μg g‐1 and stratum corneum 73 μg g‐1. Thus, 4 h after the last dose the antimycotic attains a 40‐fold higher concentration in the stratum corneum than in serum. One week after ending the oral treatment, 5.8 μg g‐1 fluconazole was present in stratum corneum. After daily ingestion of 200 mg of fluconazole for 5 days there was a further increase in the mean concentration of fluconazole in stratum corneum, to 127 μg g‐1. Even 4–5 months after completing the oral treatment, fluconazole was detectable in the head hair and toenails of healthy volunteers. Fluconazole is eliminated from the stratum corneum about 2–3 times more slowly than from serum or plasma. After oral administration fluconazole evidently accumulated rapidly and intensively into the stratum corneum. The concentrations then attained or exceeded the in vitro minimal inhibitory concentrations of fluconazole for most of the dermatophytes and yeasts which are involved in cutaneous mycoses. Zusammenfassung. Fluconazol, ein bisher vor allem in der systemischen Therapie von Sproßpilzinfektionen etabliertes Antimykotikum, wird in verschiedenen Strukturen der Haut nachgewiesen. Nach oraler Einnahme von 50 mg Fluconazol einmal täglich über 12 Tage konnten an gesunden Probanden folgende mittlere Wirkstoffkonzentrationen gemessen werden: Serum 1.81 μg ml‐1. Schweiß 4.58 μg ml‐1. Dermis‐Epidermis (ohne Stratum corneum) 2.77 μg g‐1 und Stratum corneum 73 μg g‐1. Damit erreicht das Antimykotikum vier Stunden nach der letzten Einnahme im Stratum corneum eine etwa 40fach höhere Konzentration als im Serum. Eine Woche nach Ende der oralen Behandlung werden noch 5.8 μg g‐1 Fluconazol im Stratum corneum gefunden. Die tägliche Einnahme von 200 mg Fluconazol über fünt Tage zeigt zwei Stunden nach der letzten Applikation einen weiteren Anstieg der mittleren Fluconazol‐Konzentration im Stratum corneum auf 127 μg g‐1. Das Antimykotikum ist in Kopfhaaren und Zehennägeln gesunder Probanden noch vier bzw. fünf Monate nach Beendigung der oralen Therapie nachweisbar. Aus Stratum corneum wird Fluconazol zwei‐ bis dreimal langsamer als aus Serum oder Plasma eliminiert. Fluconazol akkumuliert nach oraler Einnahme schnell und intensiv im Stratum corneum. Die dabei gemessenen Konzentrationen überschreiten die in vitro ermittelten Minimalen Hemmkonzentrationen von Fluconazol gegenüber den meisten an kutanen Mykosen beteiligten Dermatophyten und Sproßpilzen.
Lysates obtained from amoebocytes of Limulus polyphemus, the horseshoe crab, showed gel formation after the addition of bacterial endotoxin. In contrast to living gram-negative bacteria, viable gram-positive microorganisms did not cause gelation of lysate. Nevertheless, peptidoglycan isolated from the cell walls of various gram-positive organisms did induce the reaction. However, the activity of peptidoglycan was 1,000 to 400,000 times less than that of Escherichia coli lipopolysaccharide. After exposure to lysozyme, peptidoglycan no longer gelled amoebocyte lysate, therefore apparently excluding endotoxin contamination. Gelation of amoebocyte lysate by endotoxin or peptidoglycan was inhibited by different concentrations of sodium polystyrolsulfonate. Whereas these studies confirm the specificity of the Limulus test for bacterial endotoxins, they also indicate that other substances of bacterial origin should be investigated for their ability to gel amoebocyte lysate.
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