[Effect of Inhalation of Tobramycin for 12 Months on Reduction of Hospitalisation Rate in Severe COPD]. / Inhalation von Tobramycin über 12 Monate zur Senkung der Hospitalisationsrate bei schwerer COPD mit gehäuften Hospitalisationen.

INTRODUCTION: Bacterial colonisation in stable disease of severe COPD and bronchiectasis can cause recurrent hospital treatment, which has a negative impact on the patient's prognosis. A multicentre study has investigated if daily inhalation of tobramycin for one year would lower the number of hospitalisations in severe COPD. METHODS: 44 patients with severe COPD [FEV1 % of predicted value: 42.8 ± 7,1 tobramycin group (T) and 33.5 ± 10.3 placebo group (P)] and a minimum of two hospitalisations in the year before inclusion were randomly assigned to inhale twice daily for 12 months 80 mg tobramycin or isotonic saline (placebo). Concomitant therapy was according to the GOLD guidelines. Primary end point was the number of hospitalisations in the period of study, secondary end points were pulmonary function test and 6 MWD. RESULTS: Inhalation of T changed the number of hospitalisations from 2.8 ± 0.5 per year to 3.5 ± 2.7, P from 3.0 ± 1,4 to 2.3 ± 2.2. These differences and the results for secondary endpoints did not reach significance. The dropout rate was high, only 6 patients (T) and 14 patients (P) finished the study per protocol. CONCLUSION: Inhalation with 160 mg tobramycin by means of a nebuliser over a 12-month period did not reduce the number of hospitalisations for patients with severe COPD and a minimum of two hospitalisations compared to placebo. The severity of the disease was the main reason for the high dropout rate.

Pharmacokinetics and pharmacodynamics of moist inhalation epinephrine using a mobile inhaler.

BACKGROUND: Intramuscular (L-)epinephrine is used as self-medication for serious hypersensitivity reactions. Inhalative administration has the theoretical advantage of a more rapid absorption and better controllability. OBJECTIVES: The current trial was conducted to explore pharmacokinetics and pharmacodynamics of two nebulized inhalative epinephrine doses (4 mg and 8 mg in aqueous solution) using a mobile pocket inhaler relative to intramuscular administration (0.3 mg) and placebo. METHODS: This randomized, open-label, change-over pilot study involved eight young healthy men and women. Noncompartmental pharmacokinetic and pharmacodynamic parameters were calculated from epinephrine plasma concentrations and hemodynamic parameters. RESULTS: Mean exposure to epinephrine decreased from the 8 mg dose to the 4 mg inhalative dose, and further with the 0.3 mg intramuscular dose, with active treatments showing significantly higher concentrations than placebo (geometric mean area under the curve AUC0-t(last) values: 282, 236, 204 and 81.6 hr*ng/L). Maximal concentrations were reached within approximately 15 min for all active treatments. Epinephrine effects for inhalative administrations on heart rates were significantly higher than those for the intramuscular or placebo administration, while no excessive effects occurred. Pronounced overall variability prohibited a definite assessment of relative bioavailability between treatments. However, results indicated that epinephrine concentrations obtained following the 8 mg inhalative dose were not inferior to those after 0.3 mg i.m. CONCLUSIONS: A relevant fraction of moist inhalation epinephrine doses is absorbed and mediates systemic effects. This suggests that administration of epinephrine via a suitable pocket inhaler device may be beneficial in ambulatory emergency treatment of systemic hypersensitivity reactions. EudraCT number: 2010-021493-11.

Dermal absorption of permethrin following topical administration.

OBJECTIVE: Permethrin is an insecticide used in the treatment of lice and scabies infections. Although its efficacy and safety have been well documented, pharmacokinetic data are sparse. The objective of this study was to determine the systemic exposure of permethrin and the duration of residence in the human body following topical administration. METHODS: The study consisted of three parts. In six young healthy men (part 1), 50 ml of an ethanolic solution containing 215 mg permethrin (cis/trans: 25/75) was administered to the hair of the head. In another six young healthy men (part 2) and in six male or female scabies patients (part 3), 60 g of cream containing 3 g permethrin was administered to the skin of the whole body. Urine was collected up to 168 h post-dose. Urinary excretion of the main metabolite of permethrin, 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, and its conjugates was measured using a gas chromatography/electron capture detection method. RESULTS: Pharmacokinetics were similar in all study parts. The time of maximal urinary excretion rate was 12.3, 20.0 and 14.6 h, terminal elimination half-life was 32.7, 28.8 and 37.8 h and urinary recovery of the metabolite reached 0.35, 0.47 and 0.52 M percent of the permethrin dose, respectively, in parts 1, 2 and 3 (means). The treatment was well tolerated. CONCLUSIONS: The extent of systemic exposure following external therapeutic administration of permethrin is very low compared with doses used for preclinical toxicity studies, and elimination is virtually complete after 1 week. These data provide the pharmacokinetic basis for the clinical safety of topical permethrin.

Synthesis and evaluation of 17-aliphatic heterocycle-substituted steroidal inhibitors of 17alpha-hydroxylase/C17-20-lyase (P450 17).

In the search for potent inhibitors of P450 17, the key enzyme in androgen biosynthesis, a series of steroidal inhibitors were synthesized and tested toward rat and human P450 17. Small aliphatic heterocycles (aziridine, oxirane, thiirane, diaziridine, diazirine, azetidine) were introduced into the 17beta-position of anstrost-5-en-3beta-ol. After identifying that aziridine is the most suitable functional group to coordinate with the heme iron, modifications of the steroidal skeleton were performed for further optimization. A wide range of inhibitory potencies toward P450 17 were found for the 21 test compounds. The most potent inhibitors toward the human and rat enzyme were aziridine compounds 3 (IC(50) rat: 0.21 microM, K(i) = 3 nM; IC(50) human: 0.54 microM, K(i) = 8 nM), 5 (IC(50) rat: 0.43 microM, K(i) = 7 nM; IC(50) human: 0.29 microM, K(i) = 4 nM), and 8 (21R:21S = 1:1; IC(50) rat: 0.53 microM, K(i) = 9 nM; IC(50) human: 0.40 microM, K(i) = 6 nM) which were more potent than the reference ketoconazole (IC(50) rat: 67 microM; IC(50) human: 0.74 microM). The inhibitory potency depends markedly on the stereochemistry at C20 of the inhibitors. This effect is more pronounced for the rat enzyme. Tested for selectivity, the highly potent inhibitors show poor inhibitory activity toward P450 arom, P450 scc, P450 TxA(2), and 5alpha-reductase. Tested for in vivo activity, 3 and 8 (0.019 mmol/kg) decreased the plasma testosterone concentration in rats by 81% and 84% after 2 h.

Novel imidazolyl and triazolyl substituted biphenyl compounds: synthesis and evaluation as nonsteroidal inhibitors of human 17alpha-hydroxylase-C17, 20-lyase (P450 17).

The synthesis of a new series of P450 17 inhibitors is described. The imidazol-1-yl compounds 5 showed strong inhibition of P450 17 rat and especially human enzyme, the most active compounds being 5ax, 5ay and 5bx with IC50 values of 0.17, 0.24 and 0.25 microM, respectively (ketoconazole: 0.74 microM). The 1,2,4-triazol-1-yl compounds 6 were less active, while the 1,2,4-triazol-4-yl compounds 7 were inactive. The title compounds showed little inhibition of P450 arom. The most active P450 17 inhibitors 5ax and 5ay markedly decreased the testosterone plasma concentration of SD rats 2 h after application of 0.019 mmol/kg. After 6 h, 5ay still exhibited a strong effect.

Imidazole substituted biphenyls: a new class of highly potent and in vivo active inhibitors of P450 17 as potential therapeutics for treatment of prostate cancer.

3- And 4-imidazol-1-yl-methyl substituted biphenyl compounds (named as meta- and para-substituted compounds) were synthesized bearing additional substituents in 3'-/4'-position as inhibitors of P450 17 (17alpha-hydroxylase-C17,20-lyase). P450 17 is the key enzyme of androgen biosynthesis. Its inhibition is a novel therapeutic strategy for treatment of prostate cancer (PC). Twenty-nine compounds were synthesized by Ar-Mg-Br, Negishi or Suzuki aryl-aryl cross coupling and tested toward human and rat enzyme. Most of the compounds showed moderate to excellent activity against one of the enzymes (0.087 microM < or = IC50 < or = 7.7 microM (ketoconazole: 0.74 microM) for the human enzyme, 0.63 microM < or = IC50 < or = 32 microM (ketoconazole: 67 microM) for the rat enzyme). Interestingly, strong species differences were observed. In addition compounds were tested for inhibition toward P450 arom. The 3-imidazol-1-yl-methyl substituted compounds showed good inhibitory activity of P450 arom, while for the 4-substituted compounds negligible inhibition was found. For the most active group of P450 17 inhibitors, (i.e. the 4-imidazol-1-yl-methyl substituted compounds) a QSAR study was performed for inhibition of the human enzyme leading to the result that a hydrophilic substituent in 3'-/4'-position is very important. The most promising compounds (with respect to activity toward both enzymes) were tested in vivo using SD-rats for reduction of plasma testosterone concentrations 2 and 6 h after single i.p. application. The fluorine substituted compound 8c decreased the testosterone plasma concentration to castration level (after 2 h; 5 mg/kg) showing a biological half live of about 6 h.