In a double-blind controlled trial 14 chronic asthmatic patients with regular nocturnal exacerbations took 16 mg slow-release oral salbutamol (two Ventolin spandets), 450 mg slow-release aminophylline (two Phyllocontin Continus tablets), or placebo at midnight. Mean peak expiratory flow rates on waking were significantly higher on the active drugs than on placebo (p<001 for salbutamol; p < 005 for aminophylline) but neither drug abolished the overnight fall in PEFR. Plasma drug levels at 0600 hr were 17-3 ng/ml (+5 3 ng/ml SD) for salbutamol, and 7-1 ig/ml (±3 1 ig/ml SD) for theophylline. Steady-state data derived from plasma levels of salbutamol during intravenous infusion indicated that the morning salbutamol levels were probably in a therapeutic range for asthma. The morning theophylline levels, however, were suboptimal when aminophylline was given only at night.Early morning wheezing is a common symptom of asthma for which sustained release bronchodilator tablets are frequently prescribed. In normal people a diurnal variation of peak expiratory flow (PEFR) of up to 10% has been obs,erved.1 However, in asthma much larger variations frequently occur, and may sometimes pass unnoticed by the patient.2 These overnight falls in PEFR may continue apparently harmlessly foTr many years or may be associated with deterioration in the overall control of the subject's asthma.3 4Although slow-release bronchodi-lator preparations are widely prescribed to prevent nocturnal symptoms of asthma, there are few data to suggest the correct dose based on measurement of drug plasma levels. Information is available on the therapeutically effective range of plasma levels of theophylline for acute and chronic asthma, but there is no such information for salibuta,mol. This study was undertaken to investigate the plasma levels of salbutamol and theophylline produced by slow-release oral preparations, and to relate these to the degree of control achieved in chronic nocturnal asthma and
Summary
Preliminary investigation suggests that some asthmatic patients find it difficult to synchronize the release of a metered dose from a pressurized aerosol with the correct phase of inspiration. An automatic device has been developed to overcome this problem. Information is presented outlining the physical characteristics of the unit and the methods used to establish its performance in patients. It is suggested that the device may have a place in the management of asthma.
Summary
A standard Vitalograph was used to measure the volume or air inspired through the mouth (M‐FIV0.5) and nose (N‐FIV0.5) in 0.5 sec. The ratio or these parameters was used as a nasal patency index (NPI) and the characteristics of NPI and N‐FIV0.5 investigated in terms of reproducibility and sensitivity. Both indices were significantly reduced by intranasal histamine (100μg and 200 μg) and it is concluded that NPI and N‐FIV0.5 are reproducible and sensitive indices of nasal patency.
Summary
A new indoor nasal allergen challenge system has been developed which allows subjects with hay fever to be exposed to pre‐determined concentration of grass pollen grains in the immediate environment. Thirteen subjects were exposed during the winter months to an atmosphere containing approximately 1000 grains/m3 for 30 min. No changes in nasal airway patency or symptoms of nasal congestion were recorded. It was necessary to increase the pollen concentration to approximately 9000 and 35 000 grains/m3 in two subjects and six subjects respectively, before a positive response was recorded. This response was reproducible in all subjects. Administration of intra‐nasal sodium cromoglycate before exposure significantly inhibited the decrease in nasal airway patency and when administered 1 min before exposure totally abolished symptoms of nasal congestion. This new challenge system may therefore be used as an in vivo screen to assess the potential therapeutic value of drugs in hay fever under controlled conditions.
Ranitidine, 300 mg daily, was given to 92 patients with duodenal ulcer (DU), 38 with prepyloric ulcer (PPU), and 21 with gastric corporeal ulcer (GCU). The healing rates at 4 weeks differed for the different types of ulcers (P less than 0.01), being 91% for DU, 68% for PPU, and 81% for GCU. After established ulcer healing, maintenance treatment with either ranitidine, 100 mg twice daily or 150 mg at night, or placebo was given for 1 year or until ulcer relapse in a total of 108 patients--71 with DU, 24 with PPU, and 13 with GCU. There were no significant differences in relapse rates between the two groups treated with active drug or between the three ulcer groups. However, the overall relapse rate in the active drug groups was 16%, against 72% in the placebo group (P less than 0.001).
Salbutamol (8 mg) was administered twice daily as a sustained release formulation to twenty‐four asthmatic patients for up to four weeks under double‐blind conditions. 2. The ability of bronchial smooth muscle to respond was determined by monitoring the response to salbutamol (200 mug) administered by aerosol at set intervals three times a week. 3. There was no evidence of diminishing response during the study period. 4. It is concluded that tolerance to salbutamol does not occur at therapeutic dose levels and that clinical observations of tolerance may be due to other factors.
1 A method for monitoring the effect of drugs on the genital response to stimulation provided by vibration is described. 2 Using this method, the effect on male sexual response of two oral doses (100 mg and 300 mg) labetalol were studied and compared with placebo in six subjects. 3 Labetalol did not affect the attainment or maintenance of erection. 4 Labetalol delayed ejaculation in a dose-related manner. 5 Labetalol treatment resulted in a significant dose-related delay in detumescence.
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