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Biomedical subjects

D W Empey

Publications and source records attributed to D W Empey.

At least 55 records · Page 3Linked to original sources
PubMed1980

Effects of pseudoephedrine and triprolidine, alone and in combination, on symptoms of the common cold.

A total of 466 healthy adults from four different regions of England entered a double-blind, randomised trial to test the effectiveness of an antihistamine (triprolidine) and a decongestant (pseudoephedrine), alone or in combination, in relieving symptoms of the common cold. During the study 199 subjects reported a total of 243 colds. Subjects recorded the severity of 12 symptoms during treatment and noted separately the severity of a further seven symptoms that represented unwanted effects of treatment or served as an index of suggestibility. They were then asked about their overall improvement in symptoms during treatment and whether they thought they had taken placebo. Sneezing, nasal obstruction, and overall response to treatment were significantly improved (p <0.01) with psuedoephedrine or pseudoephedrine and triprolidine compared with placebo.

Clinical Trials as Topic↗
PubMed1980

Dose-response study of the nasal decongestant and cardiovascular effects of pseudoephedrine.

1 The effects of different doses of orally administered pseudoephedrine on nasal airway resistance (NAR) were studied in a group of eighteen healthy subjects using double-blind conditions with drugs administered in a series of cross-over experiments according to a Latin-square design. 2 Challenge with 1% histamine diphosphate to one nostril 1 h after administration of the drugs produced increases in NAR. 3 The effects of pre-treatment with both placebo and increasing doses of pseudoephedrine on this histamine-induced increase in NAR were examined. Pseudoephedrine 60 mg, 120 mg and 180 mg significantly (P less than 0.05) reduced the effect of histamine on NAR compared with the placebo, and the protective effects of these doses did not differ significantly from each other. Pseudoephedrine 15 mg and 30 mg did not differ from placebo in their effects on NAR. 4 Small, but statistically significant increases in pulse and systolic blood pressure occurred after pseudoephedrine 120 mg and 180 mg, but not after pseudoephedrine 60 mg, 30 mg or 15 mg. No significant effects were produced by any of the doses of pseudephedrine with regard to diastolic blood pressure. Similarly no dose of pseudoephedrine altered mood or produced any excess of unwanted effects compared with placebo. 5 We conclude that pseudoephedrine 60 mg is the optimal single adult dose since this achieves maximal nasal decongestion without cardiovascular or other unwanted effects.

Adult↗
PubMed1979

Comparison of the antitussive effects of codeine phosphate 20 mg, dextromethorphan 30 mg and noscapine 30 mg using citric acid-induced cough in normal subjects.

1. Protection by codeine 20 mg, dextromethorphan 30 mg, noscapine 30 mg, and placebo against citric acid-induced cough was determined in eighteen healthy subjects. 2. Drug differences occurred at 2 1/2 h following ingestion of the drugs but not at 1 1/4 h. 3. Only coideine 20 mg had a greater antitussive action than placebo, but dextromethorphan 30 mg also did not differ from codeine 20 mg. 4. This technique may offer a useful screening test for the activity of new potential antitussive compounds in man.

Antitussive Agents↗
PubMed1979

Two doses of triprolidine for treatment of allergic rhinitis.

Two doses of triprolidine (2.5 mg t.i.d. and 1.25 mg t.i.d.) were compared with placebo in 32 patients suffering from allergic rhinitis. Triprolidine 2.5 mg t.i.d. was statistically significantly better than placebo (p less than 0.05) in reducing the symptoms of sneezing and eye irritation. Neither dose of triprolidine produced significant drowsiness during the second week of treatment.

Adolescent↗
PubMed1978

Asthma.

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Adult↗
PubMed1978

Histamine challenge and anterior nasal rhinometry: their use in the assessment of pseudoephedrine and triprolidine as nasal decongestants in subjects with hayfever.

1 Nasal airway resistance (NAR) was measured by anterior rhinometry in ten volunteers with allergic rhinitis. Measurements before and after challenge with three concentrations of histamine diphosphate showed significant rises in NAR for each challenge. 2 In a double-blind, crossover study with the same patients triprolidine (2.5 mg) and pseudoephedrine (60 mg) were shown to be equally effective in reducing the rise in NAR produced by histamine challenge to one nostril; both were significantly better than placebo. 3 The rise in NAR of both nostrils after histamine challenge to one nostril was significantly reduced after pseudoephedrine compared with placebo. This suggests that pseudoephedrine is effective in preventing reflex mucosal congestion in the unchallenged nostril. 4 No increase in the pulse rate or blood pressure of the volunteers was detected after either drug.

Adult↗
PubMed1976

Mechanisms of bronchial hyperreactivity in normal subjects after upper respiratory tract infection.

Inhalation of histamine diphosphate aerosol (1.6 per cent, 10 breaths) produced a 218 +/- 54.6 per cent (mean +/- SE) increase in airway resistance in 16 normal subjects with colds compared with a 30.5 +/- 5.5 per cent increase in 11 healthy control subjects (P less than 0.01). There was no significant difference in mean baseline airway resistance between the two groups. Inhalation of saline produced no significant change in airway resistance in either group. Isoproterenol hydrochloride (0.5 per cent, 1 breath) or atropine sulfate aerosol (0.2 per cent, 20 breaths) each reversed and prevented the increase in airway resistance by histamine, indicating that the bronchoconstriction was caused by smooth muscle contraction and that post-ganglionic, cholinergic pathways were involved in the mechanism. In 6 subjects with colds, citric acid aerosol (10 per cent, 5 breaths) caused bronchoconstriction that lasted up to 30 sec after inhalation, a significantly greater effect than that observed in control subjects or in the same subjects after recovery (P less than 0.05). Prior inhalation of atropine aerosol (0.2 per cent, 20 breaths) prevented the bronchoconstriction after citric acid aerosol in all 6 subjects. The threshold concentration of citric acid that produced cough in 7 subjects with colds was significantly lower than that in control subjects or in the 7 subjects after recovery (P less than 0.05), suggesting that the exaggerated cholinergic response was due to a decreased threshold for stimulation of the rapidly adapting sensory receptors in the airways. We have provided evidence that respiratory viral infections that produce airway epithelial damage temporarily cause these subjects to develop more bronchoconstriction after inhaling smaller doses of histamine than do healthy subjects. The fact that atropine prevents this response and that the threshold to cough is temporarily decreased is compatible with our hypothesis that airway epithelial damage by infection exposes and, thus, "sensitizes" the rapidly adapting airway receptors to inhaled irritants, causing increased bronchoconstriction via a vagal reflex. Damage to the airway epithelium may occur as a result of mechanical factors, inhaled chemicals, and pollutants, such as ozone, infections, or perhaps as a result of the action of materials released endogenously (e.g., from mast cells, white blood cells, or platelets). "Sensitization" of rapidly adapting sensory receptors in the airways may be an important factor in asthma and in other diseases of airways.

Aerosols↗
PubMed1976

Effects of intravenous histamine on static lung compliance and airway resistance in normal man.

Static lung compliance and airway resistance were measured in 30 experiments on 6 healthy subjects after intravenous injection of a bolus of histamine (4 mug per kg of body weight). Analysis of the pooled results showed a significant decrease in static lung compliance (maximal mean decrease,--16 per cent occurring 20 sec after injection). There was no significant change in functional residual capacity or vital capacity after injection of the histamine. Administration of propranolol (a beta-adrenergic blocking agent) did not significantly enhance the responses to histamine. The results suggested that humans, like other species, can constrict peripheral airways sufficiently to produce alterations in the static elastic properties of the lungs.

Adult↗
PubMed1975

A Double-blind crossover trial of pseudoephedrine and triprolidine, alone and in combination, for the treatment of allergenic rhinitis.

In a double-blind crossover trial of pseudoephedrine 60 mg and triprolidine 2.5 mg, alone and in combination, on 40 volunteers suffering from allergic rhinitis, both drugs were found superior to placebo in reducing the effects of allergic rhinitis and were of equal efficacy. The combination tablet was consistently better than either drug in several of the assessments and was the treatment which the subjects, as a whole, preferred. Side effects were not a problem with any of the medications.

Adult↗
PubMed1972

Ten years' experience in running a pulmonary function laboratory.

A survey of the development and work of a pulmonary function laboratory in a teaching hospital over a 10-year period has shown an increasing demand for pulmonary function tests from all departments, in particular some of the surgical ones. Though no arrangement for staffing and equipping such a laboratory is ideal quite a lot of useful clinical information can be derived from a few simple tests performed in a central laboratory.

Carbon Dioxide↗
PubMed1972

Assessment of upper airways obstruction.

An indication of obstruction to the upper airways (trachea and larynx) may be obtained by calculating the ratio of the forced expired volume in one second to the peak expiratory flow rate (FEV(1)/PEFR). This index was found to be usually less than 10 in normal subjects (mean 7.3), and in patients with asthma (mean 6.9), chronic bronchitis (mean 7.7), or interstitial lung disease (mean 6.3). A study of simulated upper airways obstruction showed that this index rises as the obstruction becomes more severe. All of 18 patients with proved upper airways obstruction had FEV(1)/PEFR indices greater than 10 (mean 14.0). This test can be carried out with forced expiratory manoeuvres only, and it does not require the use of complicated equipment. An FEV(1)/PEFR ratio greater than 10, when upper airways obstruction is suspected, indicates that significant obstruction may be present. High values suggest that the obstruction may be severe, and that further investigations are indicated.

Adolescent↗