Pharmacokinetics of the triazole antifungal agent genaconazole in healthy men after oral and intravenous administration

Excretion and ecotoxicity of pharmaceutical and personal care products in the environment

The presence and fate of pharmaceutical and personal care products (PPCPs) in the environment is undergoing increasing scrutiny. The existing clinical pharmacokinetics and pharmacodynamics data for 81 common compounds were examined for cues of ecotoxicity. Of these the proportions excreted were available for 60 compounds (i.e., 74%). The compounds had a low (< or =0.5%), a moderately low (6-39%), a relatively high (40-69%), or a high (> or =70%) proportion of the parent compound excreted. More than half of the compounds evaluated have low or moderately low proportions of the parent compound excreted. However, the proportions excreted were negatively but moderately correlated (r = -0.50; n = 13; P = 0.08) with the concentrations of the compounds in the aquatic environment, suggesting that the compounds that have low proportions excreted may also have inherently low degradability in the environment. Solubility, logK(ow), and pKa work well in predicting the behavior of PPCPs under clinical conditions and have been used in the environmental assessment of PPCPs prior to approval. However, these parameters did not correlate with the proportion of PPCPs excreted in the environment or their concentration in the environment, underscoring the need for research into the behavior of PPCPs in the environment. PPCPs occur in low concentrations in the environment and are unlikely to elicit acute toxicity. An ecotoxicity potential that is based on chronic toxicity, bioavailability, and duration of exposure to nontarget organisms is described as a guide in assessing the potency of these compounds in the environment.

[Review article. Molecular basis of antimycotic therapy]

A review is presented on the hitherto clinically administered antimycotic drugs, their action mechanisms and limitations as well as on the presently newly developed antifungals and their molecular targets.

Pharmacokinetics and metabolism of genaconazole, a potent antifungal drug, in men

The pharmacokinetics of genaconazole, a racemic triazole antifungal agent comprising 50% RR and 50% SS enantiomers, were studied in 12 healthy male volunteers after a single oral dose of 200 mg. The serum samples were analyzed for the two enantiomers by using a chiral high-pressure liquid chromatography assay. The concentrations of the RR and SS enantiomers in serum were virtually identical. The mean values for the maximum concentrations in serum (Cmax) (1.7 micrograms/ml), times to Cmax (4.0 to 4.2 h), half-lives (83 h), and areas under the concentration-time curve from 0 h to infinity (195 to 199 micrograms.h/ml) were similar for the two enantiomers. The results showed that the pharmacokinetic profiles of the two enantiomers were similar after a single oral dosing of the racemate. The pharmacokinetics of the RR enantiomer were also evaluated in 12 healthy male volunteers after a single oral dose of 100 or 200 mg. The ratios of the Cmaxs and of the areas under the concentration-time curves from 0 h to infinity for the two doses were about 2, indicating a dose proportionality. In a separate study, six healthy male volunteers received a single oral dose of 50 mg of 14C-labeled genaconazole. The Cmax values for total radioactivity (14C) and intact genaconazole were virtually identical (0.6 micrograms/ml). The mean half-lives in serum were about 73 h for both total radioactivity and genaconazole. The amounts of total radioactivity excreted in the 0 to 240-h interval (representing approximately three half-lives) in urine and feces were 66.6 and 9.3% of the dose, respectively; 64.4% of the dose was excreted in urine as parent drug. There were no detectable metabolites in either serum or urine. The data demonstrate that genaconazole (racemate) is well absorbed, undergoes negligible biotransformation, and is slowly excreted, primarily in the urine.