In vitro antimicrobial activity of pannarin alone and in combination with antibiotics against methicillin-resistant Staphylococcus aureus clinical isolates.

The in vitro antimicrobial activities of pannarin, a depsidone isolated from lichens, collected in several Southern regions of Chile (including Antarctica), was evaluated alone and in combination with five therapeutically available antibiotics, using checkerboard microdilution assay against methicillin-resistant clinical isolates strains of Staphylococcus aureus. MIC(90), MIC(50), as well as MBC(90) and MBC(50), were evaluated. A moderate synergistic action was observed in combination with gentamicin, whilst antagonism was observed in combination with levofloxacin. All combinations with erythromycin were indifferent, whilst variability was observed for clindamycin and oxacillin combinations. Data from checkerboard assay were analysed and interpreted using the fractional inhibitory concentration index and the response surface approach using the ΔE model. Discrepancies were found between both methods for some combinations. In order to asses cellular lysis after exposure to pannarin, cell membrane permeability assay was performed. The treatment with pannarin produces bactericidal activity without significant calcein release, consistent with lack of lysis or even significant structural damage to the cytoplasmic membrane. Furthermore, pannarin shows low hemolytic activity and moderate cytotoxic effect on peripheral blood mononuclear cells. These findings suggest that the natural compound pannarin might be a good candidate for the individualization of novel templates for the development of new antimicrobial agents or combinations of drugs for chemotherapy.

Hyperprolactinaemia and depression induced by oxetorone.

Two cases of hyperprolactinaemia and one case of depression caused by oxetorone are described. These rare side effects are probably related to the pharmacological properties of the drug.

Tolerance and pharmacokinetics of a new antiulcer compound in man after single oral doses.

5-[(2-Diethylamino)ethyl]amino-5,11-dihydro[1]benzoxepino[3,4- b]pyridine trihydrochloride (KW-5805) is a new antiulcer compound, which was effective in animal studies by increasing gastric mucus and stimulating defensive factors such as glucosamine-synthesizing enzymes rather than by inhibiting aggressive factors. In this placebo-controlled, double-blind study the tolerability and pharmacokinetics of KW-5805 have been evaluated first time in man. Single oral doses of 2.5 to 320 mg were administered to 3 healthy young male subjects per dose level. One additional subject received placebo at each dose level. Plasma and urine samples were collected up to 24 h after administration and analysed gaschromatographically respectively by a high performance liquid chromatography. The mean maximum concentrations in plasma of KW-5805 occurred between 1.17 and 3.33 h after administration, independent of the dose. The half-lives of elimination varied between 6.63 and 11.9 h. 13.4-23.7, 9.6-13.4 and 6.5-11.0% of the administered dose were recovered in the urine after 24 h as unchanged substance, as monodeethylated (M-1) and as hydroxylated (M-3) metabolite, respectively. KW-5805 was not associated with any clinically significant effect on vital signs, ECG or laboratory investigations. Subjectively and objectively the substance was well tolerated in the dose range administered.

Dibenz[b,e]oxepinalkanoic acids as nonsteroidal antiinflammatory agents. 2. Dihydro-10-oxofuro-and -thieno[3,2-c][1]benzoxepin-8-acetic acids.

4,10-Dihydro-10-oxofuro[3,2-c][1]benzoxepin-8-acetic acid and 4,10-dihydro-10-oxothieno[3,2-c][1]benzoxepin-8-acetic acid were evaluated in the carrageenan paw edema assay with the thieno analogue being ten times more active than the furano compound and 1.3. times more active than indomethacin. The therapeutic ratio (antiinflammatory activity/gastric irritation liability) of the thieno analogue was 25 times that of indomethacin.