title: Trials of the bronchodilator activity of the xanthine analogue SDZ MKS 492 in healthy volunteers during a methacholine challenge test.
abstract: An approximately steady-state reduction of specific airway conductance was induced in healthy human subjects by means of an individualized inhaled methacholine loading dose followed by a maintenance dose regime. Tested against this background bronchoconstriction, the xanthine analogue SDZ MKS 492, when administered as a single oral dose of 40 mg, showed a significant bronchodilator action, which lasted for up to 5.5 h. Bronchodilatation was not seen after administration of 10 or 20 mg doses. SDZ MKS 492 inhaled as a dry powder had a bronchodilator action that was small, most evident with the 12 mg dose and transient. The peak relief of imposed bronchoconstriction was 29% and the apparent half-time of removal of SDZ MKS 492 from its site of action was 5-6 min. Inhaled SDZ 492 had a bitter taste that was not masked by inclusion of menthol and aspartame in the formulation. The bronchodilatation seen in laboratory animals can also be produced by SDZ MKS 492 in man when administered orally or by inhalation. Its magnitude correlates better with the plasma concentration of parent drug than with that of either of the identified metabolites. Dispositional processes in the lung abbreviate its action after administration by inhalation.
authors.affiliation: Department of Physiological Sciences, Medical School, University of Manchester, UK.
authors.forename: R W
authors.initials: RW
authors.lastname: Foster
authors.forename: A S
authors.initials: AS
authors.lastname: Jubber
authors.forename: N A
authors.initials: NA
authors.lastname: Hassan
authors.forename: B
authors.initials: B
authors.lastname: Franke
authors.forename: L
authors.initials: L
authors.lastname: Vernillet
authors.forename: J
authors.initials: J
authors.lastname: Denouel
authors.forename: J R
authors.initials: JR
authors.lastname: Carpenter
authors.forename: R C
authors.initials: RC
authors.lastname: Small
mesh_terms: D000280:Administration, Inhalation; D000284:Administration, Oral; D000328:Adult; D000818:Animals; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000187:drug effects*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D010993:Plethysmography, Whole Body; D011688:Purinones / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
chemical_list: D001993:Bronchodilator Agents; D011688:Purinones; D016210:Methacholine Chloride; C073029:SDZ MKS 492