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Biomedical subjects

G E Marlin

Publications and source records attributed to G E Marlin.

At least 37 records · Page 2Linked to original sources

The metabolic actions of intravenous salbutamol and aminophylline singly and in combination.

1 The following four treatments were administered by constant intravenous infusion of four healthy volunteers in a balanced randomized study: 1) saline (30 min), salbutamol (0.15 micrograms kg-1 min-1 for 30 min) (sS), 2) saline, aminophylline (0.2 mg kg-1 min-1 for 30 min) (sA), 3) salbutamol, salbutamol (SS) and 4) aminophylline, salbutamol (AS). 2 Heart rate was recorded and venous blood taken for estimation of insulin, glucose, potassium and theophylline before and during the infusions (10, 20, 30, 40, 50 and 60 min). 3 The mean, peak heart rate increases from control, baseline values were 23.0 (sS), 3.5 (sA), 28.5 (SS) and 28.0 (AS) beats/min, the mean, peak insulin increases, 34.0 (sS), 0.5 (sA), 39.0 (SS) and 57.5 (AS) microU ml-1, the mean, peak glucose increases, 1.4 (sS), 0.1 (sA), 2.6 (SS) and 2.0 (AS) mmol 1(-1) and the mean, peak potassium changes, -0.45 (sS), 0.58 (sA), -0.78 (SS) and -0.68 (AS) mmol 1(-1). 4 The mean, peak serum theophylline levels were 48.1 mumol 1(-1) at 60 min in sA and 52.6 mumol 1(-1) at 50 min in AS (39.1 mumol 1(-1) at 30 min). 5 Salbutamol stimulated significant insulin release and produced hypokalaemia and glycogenolysis, whereas aminophylline induced no metabolic effect. 6 A comparison of sS and AS indicated a trend for aminophylline to potentiate the metabolic effects of salbutamol.

Adult↗

Comparison of ipratropium bromide and salbutamol by aerosolized solution.

Ipratropium bromide (0.125 mg, 0.25 mg and 0.5 mg) and salbutamol (5 mg) by aerosolized solution produced equivalent peak bronchodilatation between one and two hours after administration to ten patients with chronic partially reversible airways obstruction. The duration of action of the two higher doses of ipratropium bromide (0.25 mg--6 hours; 0.5 mg--5 hours) was significantly greater than salbutamol (4 hours). FVC increases with both drugs and saline were greater than FEV1 increases which may indicate dilatation of small peripheral airways or removal of bronchial mucus from these sites after coughing. A dose of 0.25 mg ipratropium bromide as an aerosolised solution is recommended for clinical use.

Aerosols↗

Penetration of piperacillin into bronchial mucosa and sputum.

Bronchial mucosal biopsies were obtained during fibreoptic bronchoscopy in 12 patients receiving a new semisynthetic penicillin, piperacillin. The piperacillin levels estimated in bronchial mucosa exceeded those required to eradicate organisms associated with acute bronchitis, Haemophilus influenzae and Streptococcus pneumoniae, and compared favourably with those required for activity against a wide variety of anaerobic and Gram-negative organisms including Pseudomonas aeruginosa. Sputum and serum piperacillin levels were obtained from eight patients with bronchial disease receiving a five to seven day course (8 to 16 g/day). Sputum/serum level ratios were constant for the two dosages (10.7% for 8 g/day; 14.3% for 16 g/day) suggesting a diffusion transfer process, although the presence of pus in the sputum appeared to facilitate penetration. Seven patients achieved sputum levels exceeding those required for activity against Haemophilus influenzae and Streptococcus influenzae, and four for Pseudomonas aeruginosa. This study provides pharmacolinetic support of the use of piperacillin in bronchopulmonary infection.

Aged↗

Clinical evaluation of piperacillin in bronchopulmonary infection.

Piperacillin sodium, a new semi-synthetic penicillin, was administered to eleven patients with acute bronchial infection and to fourteen patients with pneumonia. Piperacillin dosage was either 8 g/day (twenty-one patients) or 16 g/day (four patients) intravenously for periods of between 5 and 15 days. Clinical assessment was determined by diminution of sputum purulence, eradication of pathogen from sputum, clinical and radiological progress. There was a beneficial response in all but six patients, two of whom had severe chronic infective bronchial disease and four had underlying pulmonary malignancy. The low toxicity of piperacillin was confirmed, although one patient with chronic renal failure had a significant decline in renal function. Dosage should be reduced in patients with renal impairment.

Aged↗

Small airways disease: reproducibility of measurements and correlation with lung function.

Three measurements of small airway dimensions and a measurement of lesions in small airways were made in 32 human lungs obtained at autopsy in order to assess the intraobserver and interobserver variability of these measurements and their interrelationships. The same measurements were then made in 22 lobes resected in patients with known lung function. Small airway dimensions were smaller in surgically resected lobes compared to autopsy lungs suggesting persistence of muscle tone in the surgical specimens.

Airway Obstruction↗

The maximum expiratory flow-volume curve with air and a low-density gas misture. An analysis of subject and observer variability.

The subject and intra- and inter-observer variability of three measurements derived from the maximal expiratory flow-volume (MEFV) curve with air and helium-oxygen (HeO2) mixture was determined in ten normal subjects who produced curves in the morning and afternoon of three consecutive days and again on one day a month later. The measurements examined were the maximum flow at 50% vital capacity (V50), the percentage increases in V50 when breathing the He-O2 mixture (delta V50), and the volume at which the curves on air and He-O2 first meet or intersect (VisoV). The delta V50 and VisoV were shown to have a greater degree of variability than the V50 and, in the case of VisoV, this was contributed to significantly by the observer variability. The within-subject variability of the delta V50 and VisoV was so great that the usefulness of these tests in following changes in lung function of individual patients must be questioned.

Adult↗

Sputum and plasma doxycycline concentrations after a single oral 600 mg doxycycline dose in patients with chronic bronchitis.

Plasma and sputum concentrations of doxycycline were measured in 10 patients with chronic bronchitis for a period of 96 h after a single oral 600 mg dose of doxycycline. The plasma doxycycline levels exceeded the minimal inhibitory concentrations (MIC) against common respiratory pathogens. Sputum doxycycline levels were detected in nine patients and these compared favourably with the above MICs for 24 h. The mean percent ratio of sputum/plasma doxycycline level reached a maximum of 28% at 48 h. There was a positive correlation between sputum and plasma doxycycline levels. This study provides pharmacokinetic support for a single oral 600 mg dose of doxycycline in the treatment of acute bronchial infection.

Aged↗

Serum level monitoring of a new slow release theophylline formulation in patients with chronic lung disease.

1 Serum theophylline levels were performed in 26 patients with chronic lung disease receiving rapid release theophylline (125 mg 6 hourly) and 28 patients receiving slow release theophylline (250 mg 12 hourly) under steady state conditions. 2 For rapid release theophylline the mean +/- s.d. serum theophylline levels at 0 and 2 h were 41.0 +/- 21.7 and 52.3 +/- 20.9 mumol l-1 respectively and for slow release theophylline at 0, 4 and 6 h 43.7 +/- 25.5, 50.9 +/- 23.0 and 51.7 +/- 26.4 mumol l-1 respectively. 3 Serum theophylline monitoring with slow release theophylline was performed in 70 patients with chronic lung disease. The initial dose was 250 mg administered 12 hourly. 4 The mean +/- s.d. steady state serum theophylline level achieved was 76.0 +/- 18.8 mumol l-1 and the mean +/- s.d. dose to produce this level was 9.4 +/ 2.3 mg kg-1 day-1. There was no correlation between dosage and serum theophylline level. 5 Sixty percent of patients required a dosage change for stabilization (375 to 1000 mg/day). Seventeen patients reported unwanted effects (nausea or tremor), which either settled quickly or resolved with dosage reduction. 6 Serum theophylline levels were obtained at different dosages in 44 patients and 18 patients demonstrated dose-dependent kinetics. 7 An initial dose of 500 mg/day is recommended and dosage increments should not exceed 125 mg/day with monitoring by serum theophylline levels.

Aged↗

Influence of food on absorption of erythromycin ethyl succinate.

Erythromycin plasma concentrations were determined in 18 subjects after a single dose (800 mg) of a new formulation of erythromycin ethyl succinate taken immediately before, immediately after, and 1 h after food. Adequate absorption occurred with all treatments, although bioavailability was best when the drug was taken before food. Absorption was delayed by food, with the highest and earliest peak plasma erythromycin levels occurring under fasting conditions.

Adult↗

Effects of lobectomy on lung function.

The effect of lobectomy on lung function was investigated in 16 patients in whom comprehensive lung function tests were performed before and between six weeks and six months after lobectomy. The operation was well tolerated even by patients with quite severe airways obstruction. The effect of lobectomy on forced flow rates was in keeping with the change in lung volumes. There was no alteration in the distribution of ventilation and the diffusion capacity remained unchanged. The changes in the pressure volume curves were difficult to explain. All patients, even those with nearly "complete" hyperinflation of the remaining lung, had appreciable increases in maximal intrapleural pressure at full inspiration.

Aged↗

Plasma and sputum erythromycin concentrations in chronic bronchitis.

Plasma and sputum concentrations of erythromycin were measured in 10 patients with chronic bronchitis during an eight-day course of a new formulation of erythromycin stearate. The plasma erythromycin levels compared favourably with the minimal inhibitory concentrations for common respiratory pathogens and indicated adequate gastrointestinal absorption when the drug was taken immediately before food. Sputum erythromycin levels were variable and in some patients low or undetectable. Measurable sputum erythromycin levels were approximately 10% of plasma levels with no evidence of accumulation and were of similar order of magnitude to the minimal inhibitory concentrations for common respiratory pathogens except Haemophilus influenzae. There was no correlation between sputum and plasma erythromycin levels. There was a trend for higher erythromycin levels in sputum containing increasing amounts of pus and also when plasma levels increased.

Aged↗

Pharmacokinetics and tolerability of a single oral 600-mg dose of doxycycline.

The pharmacokinetics of a single orally administered 600-mg dose of doxycycline (six 100-mg film-coated tablets) was studied in 18 healthy subjects. Plasma doxycycline levels remained above 1.35 mumol/L for 48 hours and compared favourably with the mean inhibitory concentrations of doxycycline against the common infecting organisms in chronic bronchitis. In a separate tolerability study in 37 healthy subjects, there was no significant difference between doxycycline and placebo in the incidence of adverse effects.

Adult↗

The influence of food on the bioavailability of new formulations of erythromycin stearate and base.

1. The effect of food on the bioavailability of two new formulations of erythromycin, 1) erythromycin stearate, 500 mg (Erythrocin, 250 mg capsule-shaped tablets) and 2) erythromycin base, 500 mg (Eryc, 250 mg capsules containing enteric-coated pellets) was studied in 16 healthy subjects. 2. The study was a balanced, randomized Latin square design and was conducted on 4 days. The four treatments were erythromycin stearate immediately before (EB) and after EA) breakfast and erythromycin base immediately before (eB) and after (eA) breakfast. 3. The mean +/- s.d. maximal plasma erythromycin concentrations were 2.09 +/- 1.06, 0.37 +/- 0.40, 1.8+ +/- 1.15 and 1.91 +/- 1.57 micrograms/ml and the mean +/- s.d. times at which these occurred were 1.3 +/- 0.7, 2.3 +/- 0.9, 4.4 +/- 1.9 and 4.3 +/- 1.1 h for EB, EA, eB and eA respectively. 4. The mean +/- s.d. areas under the curves (0 to 8 h) were 4.99 +/- 2.41, 1.04 +/- 1.57, 4.93 +/- 2.98 and 4.98 +/- 3.14 for EB, EA, eB and eA respectively. 5. The bioavailability of erythromycin stearate was significantly reduced by the prior administration of food, whereas the absorption of the base was not inhibited by food.

Adult↗

Combined cholinergic antagonist and beta 2-adrenoceptor agonist bronchodilator therapy by inhalation.

The bronchodilator effects of 40 microgram ipratropium bromide (I) and 400 microgram fenoterol (F) by pressurised aerosol and both drugs in combination were compared with placebo (P) in a double-blind study in eight patients with chronic, partially reversible airways obstruction. The four treatments were (1) IP, (2) PF, (3) IF and (4) PP, with the second aerosol administered two hours after the first. Both drugs produced significant bronchodilatation for five hours, the response being greater and more rapid in onset with fenoterol. Both drugs in combination (IF) produced significant additive bronchodilatation from three to six hours after fenoterol. This additive effect may have been due to the improved lung function caused by ipratropium bromide and does not imply a synergistic effect. There were no side-effects reported. The results suggest that both ipratropium bromide and fenoterol are effective bronchodilating agents in patients with chronic asthma.

Adult↗

Tracheobronchopathia osteochondroplastica.

The clinical, pathological and physiological features of two patients suffering from tracheobronchopathia osteochondroplastica (TO) are described. Unequivocal evidence of extrapulmonary airways obstruction was not able to be obtained by lung function testing, despite extensive central airway involvement in both patients. TO is a rare condition of which there is only one other clinical report from this country. As the bronchoscopic appearance may closely resemble that of endobronchial neoplasms, TO should be remembered in the differential diagnosis of patients with haemoptysis.

Aged↗