American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jun 1998
Randomized Controlled Trial Clinical TrialThe effect of sustained-release morphine on breathlessness and quality of life in severe chronic obstructive pulmonary disease.
Morphine has been proposed as a treatment for breathlessness in patients with severe chronic obstructive pulmonary disease (COPD), but there is uncertainty as to whether or not it is effective. Orally administered sustained-release morphine was compared with placebo in a randomized, double-blind, crossover trial with two 6-wk treatment periods separated by a 2-wk washout period. The primary end point was quality of life measured using the Chronic Respiratory Disease Questionnaire (CRQ). ⋯ There were no differences between treatments in breathlessness scored on daily diary cards or on the Dyspnea subscale of the CRQ. Almost all the subjects experienced adverse effects related to morphine. Sustained-release morphine was not a useful treatment for breathlessness in these patients with severe COPD.
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Am. J. Respir. Crit. Care Med. · Jun 1998
ReviewChemistry and structure--activity relationships of leukotriene receptor antagonists.
Several strategies have been employed by medicinal chemists in the design of potent and selective leukotriene receptor antagonists-leukotriene structural analogs, FPL 55712 analogs, and random screening of corporate compound banks. Lead compounds were optimized, often through the exchange of ideas with groups working on other chemical series of leukotriene antagonists. ⋯ Zafirlukast is based on a lead compound that incorporated structural components from both FPL 55712 and the leukotrienes. Therefore, each medicinal chemistry strategy that was originally employed has successfully identified clinically effective leukotriene receptor antagonists.
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The initial enzymatic steps in leukotriene synthesis occur at the nuclear envelope. Cytosolic phospholipase A2 translocates from the cytoplasm to selectively hydrolyze nuclear envelope phospholipids, releasing free arachidonate. 5-Lipoxygenase-activating protein, an arachidonate transfer protein, then binds arachidonate and presents it to 5-lipoxygenase (5-LO), which catalyzes a two-step reaction to produce leukotriene A4. ⋯ Immunofluorescence microscopy studies demonstrate that both cytoplasmic and nuclear 5-LO move to the nuclear envelope following cell activation. Many questions remain unanswered regarding the significance of nuclear 5-LO, potential autocrine actions of leukotrienes, and intracellular trafficking of these enzymes and their products.
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Am. J. Respir. Crit. Care Med. · Jun 1998
Randomized Controlled Trial Comparative Study Clinical TrialRifapentine and isoniazid in the continuation phase of treating pulmonary tuberculosis. Initial report.
A randomized comparison has been made of three times weekly rifampin plus isoniazid (HR3) with rifapentine plus isoniazid given once weekly (HRp1) or on 2 of 3 wk (HRp1.2/3) in the continuation phase of 6-mo regimens (each starting with an initial 2 mo of 4-drug therapy) for the treatment of pulmonary tuberculosis in 672 Chinese patients in Hong Kong. Because of poor bioavailability of the rifapentine used (produced in China), its dose size was increased from 600 mg initially to about 750 mg in the last third of patients to obtain serum concentrations similar to those with rifapentine of Western origin; all doses were given after a meal promoting absorption. After initial exclusions, an intent to treat analysis, done on the remaining 592 patients, showed 45 adverse treatment events in 7 of 190 HR3 patients, in 17 of 199 HRp1 patients, and in 21 of 203 HRp1.2/3 patients; of these, 42 were bacteriological or radiographic relapses after the end of treatment (HR3 versus HRp1, p = 0.04; HR3 versus HRp1.2/3, p = 0.01). ⋯ The high relapse rate in the HRp1 regimen suggests that the rifapentine dose should be increased. Similarity of relapse rates, 8.9% and 10.4%, after the HRp1 and HRp1.2/3 regimens, respectively, indicates that irregularity in taking rifapentine/isoniazid could be tolerated. The few adverse side effects in the continuation phase in the rifapentine regimens were less frequent than in the HR3 regimen.
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Am. J. Respir. Crit. Care Med. · Jun 1998
Randomized Controlled Trial Clinical TrialWeight loss is a reversible factor in the prognosis of chronic obstructive pulmonary disease.
The objective of the study was to further unravel the prognostic significance of body weight changes in patients with COPD. Two survival analyses were performed: (1) a retrospective study, including 400 patients with COPD none of whom had received nutritional therapy; (2) a post hoc analysis of a prospective study, including 203 patients with COPD who had participated in a randomized placebo-controlled trial. There was no overlap between the patient groups. ⋯ On Cox regression analysis weight change entered as a time-dependent covariate remained an independent predictor of mortality in addition to all variables that were entered in the retrospective study. The combined results of the two survival analyses provide evidence to support the hypothesis that body weight has an independent effect on survival in COPD. Moreover the negative effect of low body weight can be reversed by appropriate therapy in some of the patients with COPD.