Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “COUGH”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMed1993

Safety update: focus on cough.

Overall, angiotensin-converting enzyme (ACE) inhibitors have a very low side-effect profile. However, several reports in the literature cite cough as a possible complication of ACE inhibitor therapy. These reports have prompted speculation that the risk of cough may differ among ACE inhibitors and that the risk may be greater in patients with renal impairment, perhaps because of excessive drug accumulation. However, these hypotheses have not been tested in prospective, controlled studies. Fosinopril is a long-acting ACE inhibitor with a unique chemical structure and an elimination profile that is associated with stable clearance, regardless of the degree of renal impairment. Favorable clinical experience with fosinopril led to the evaluation of this agent's cough profile in a prospective, open-label study. This study focused on the frequency of cough in patients with mild-to-moderate hypertension who had previously experienced cough while taking another ACE inhibitor. Whereas most prior controlled studies and postmarketing surveillance trials measured the frequency of cough through spontaneous adverse-event reporting, in this study a methodology previously validated in antitussive and mucolytic studies was adapted to provide accurate and sensitive measure of fosinopril's cough profile. Twenty-four patients were switched from another ACE inhibitor to fosinopril, 10 mg once daily for 6 weeks. At study end, the mean occurrence of cough, frequency of cough, and cough severity significantly changed from baseline (p < or = 0.0002). Thus, fosinopril use was associated with a less frequent, less severe cough in patients who experienced cough while taking other ACE inhibitors.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2006

Cough and asthma.

The relationship between cough and asthma is complex. Epidemiological studies now suggest that most children with recurrent cough who do not wheeze do not have asthma. These children are commonly described as having non-specific cough that appears to be due to increased cough receptor sensitivity during the coughing episode. Children with asthma who cough have also been shown to have increased cough receptor sensitivity during an acute exacerbation. Cough severity does not generally correlate with asthma severity. Apart from wheeze and dyspnoea, there are no clear distinguishing features to separate asthma from non-specific cough. To date, no specific treatment has clearly been shown to benefit children with non-specific cough. Although a trial of asthma treatment may be justified in these children, it is preferable to cease rather than escalate treatment if there is no response. In children with asthma who cough, cough should not be used as the predominant symptom to direct asthma therapy.

Asthma↗
PubMed2006

Ambulatory methods for recording cough.

Recording cough sounds to objectively quantify coughing was first performed using large reel-to-reel tape recorders more than 40 years ago. Coughs were counted manually, which is an extremely laborious and time-consuming process. Current technologies including digital recording techniques, data compression and improvements in digital storage capacity should make the process of recording and counting coughs suitable for automation; however, to date no accurate, objective cough monitoring device is available. Cough sounds are easily distinguishable from other vocalizations by the human ear and hence it is reasonable to assume that coughs sounds should have characteristic, identifying acoustic properties. However, the acoustic features of spontaneously occurring cough sounds are extremely variable. Furthermore, in even the worst cases of cough, the time spent speaking is an order of magnitude greater than the time spent coughing. It follows that even an algorithm that mistakes only a very small proportion of speech as cough will still have an unacceptable false positive rate. There is a clear need for an objective measure of cough for use in clinical practice, clinical research and trials of novel treatments. In the near future automated ambulatory systems with sufficient accuracy to be of clinical use should be available.

Acoustics↗
PubMed2006

Cough motor mechanisms.

Cough is a defensive airway mechanisms which involves the sequential activation of several laryngeal and respiratory muscles in the generation of the typical four-phase motor pattern. Activation of such muscles can be considered to represent the "primary" cough motor mechanism, and its functional significance, although complex, appears to be fairly well established. Nonetheless, the outflows of cough are numerous, and may additionally involve the reflex or mechanical activation of other respiratory and non-respiratory motor systems. These additional, or "secondary", outflows of cough can mainly be regarded as being involved in either enhancing the defensive function of cough, or opposing the possible noxious effects exerted by the mechanical stresses of coughing. In addition, both the primary and secondary cough motor mechanisms are known to play multiple functional roles, thus considerably complicating the cough panorama. Finally, some of the secondary cough motor responses, such as the changes in the pattern of breathing, seem to be devoid of any favourable action and their functional meaning, if any, is not fully understood. Although it is well known that all patterns of cough can be produced voluntarily, the extent to which also volitional cough is accompanied by an array of motor responses similar to that of reflex cough remains to be elucidated.

Animals↗
PubMed2000

Intermediate but not low doses of aspirin can suppress angiotensin-converting enzyme inhibitor-induced cough.

This self-matched control study aimed to compare the efficiency of two different regimens of active treatment: aspirin in low (100 mg daily) versus intermediate (500 mg daily) doses in abolishing angiotensin-converting enzyme inhibitor (ACEI)-induced cough. A dry bothersome cough is the most common adverse class effect of all angiotensin-converting enzyme inhibitors. Prostaglandins (PG) have been pinpointed as playing a leading role in the genesis of ACEI-associated cough. The role of different doses of the most commonly used PG inhibitor-aspirin-in ACEI cough modification was not yet elucidated. Of 350 consecutive ACEI-treated patients, we identified 34 (9.7%) nonsmoking ACEI-related coughers. Patients with lung disease, nonsteroidal anti-inflammatory drug (NSAID) treatment, and those who did not agree to participate in the study were excluded. In the remaining 14 ACEI coughers (eight men, six women; mean age, 63 +/- 11 years), the treatment was discontinued; the dry cough completely disappeared, but returned in all patients within 1 week after ACEI reintroduction. At the end of the rechallenge period, patients started a low dose of aspirin for 1 week, switching thereafter to the intermediate dose of aspirin for an additional week. On each visit the cough severity (CS, 0-4) and frequency (CF, 0-10) scores were registered. Low doses of aspirin were ineffective in suppressing ACEI-induced cough, whereas intermediate doses completely abolished cough in five patients and reduced coughing in all but one patient; CS and CF decreased, respectively, from 2.5 +/- 1.0 to 0.9 +/- 1.1, P < .002 and from 6.6 +/- 2.4 to 2.4 +/- 1.1, P < .0002. Overall, intermediate doses of aspirin beneficially modified cough scores in 13 (93%) patients, enabling nine (64%) to continue ACEI treatment. Aspirin did not influence blood pressure control either in hypertensives or in postinfarction patients. We conclude that intermediate but not low doses of aspirin probably can suppress ACEI-induced cough. These findings propose a new alternative therapeutic approach for patients with ACEI-related cough, especially those in whom ACEI treatment seems to be essential.

Aged↗
PubMed1999

Cough induced by low pH.

Citric acid has been used as a tussive agent in the investigation of the cough reflex. The mechanism of cough stimulation remains unclear. We conducted studies to compare the cough response of citric acid to an organic (acetic acid) and an inorganic acid (phosphoric acid). We also compared the cough response of citric acid to capsaicin, a non-acid tussive stimulus. In study 1, 26 subjects inhaled equimolar concentrations of citric and acetic acid. In study, 2, 22 subjects inhaled citric acid and phosphoric acid in concentrations of similar pH. Eighteen subjects from study 2 completed a capsaicin cough challenge test. The cough response was recorded and the concentration causing two coughs, the cough threshold, calculated (D2). The correlation of cough thresholds between both citric and acetic acid (r = 0.79, 95% CI 0.37-0.90, P < 0.0001) and citric acid and phosphoric acid (r = 0.68, 95% CI 0.37-0.86, P = 0.0005) were significant. There was no correlation between the citric acid and capsaicin cough thresholds. These results show that an individual's cough response to acetic and phosphoric acid are similar to that caused by citric acid. Thus these acids may cause cough by a common mechanism such as disturbance of the pH of the airway surface liquid. Capsaicin does not appear to share this common pathway.

Acetic Acid↗
PubMed1998

Malignant cough equivalent asthma: definition and case reports.

BACKGROUND: Cough equivalent asthma is a cause for chronic cough and usually responds to corticosteroid therapy. Oral corticosteroids are employed in a diagnostic-therapeutic trial and inhaled corticosteroids are employed in maintenance therapy. In certain cases the cough may be especially severe and require escalated doses of oral corticosteroids for initial control. This is labeled malignant cough equivalent asthma. OBJECTIVE: To define malignant cough equivalent asthma, provide two case reports, and identify features that should alert physicians to consider the possibility of malignant cough equivalent asthma. CASE REPORTS: We report two patients who presented complaining of chronic cough that was disruptive of sleep and normal activities, and in one patient prompted an emergency room visit and later hospitalization. The patients underwent evaluation with history, physical examination, and laboratory testing as indicated. Other causes for chronic cough were ruled out by appropriate testing, or were treated, and patients did not respond to usual corticosteroid treatment for cough equivalent asthma. These patients were considered to have a more severe form of cough equivalent asthma and did respond to treatment with higher doses of oral corticosteroids. CONCLUSION: Malignant cough equivalent asthma is a cause of chronic cough that is disruptive to sleep or normal activities, may lead to emergency room visits or hospitalization, and requires escalated doses of oral corticosteroids for initial control.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Laparoscopic antireflux surgery and its effect on cough in patients with gastroesophageal reflux disease.

In addition to heartburn and regurgitation, cough is a frequent nonspecific complaint of patients with gastroesophageal reflux disease. The incidence of alternative etiologies for patients with chronic cough who are undergoing antireflux surgery is not known. To determine this, and the response of chronic cough to fundoplication, we performed a retrospective review of 129 patients with proven gastroesophageal reflux referred for surgical therapy. Chronic cough was present in 37 (29%) preoperatively. No differences were found in age, sex, or preoperative manometric findings between those with and without chronic cough. Patients with cough had a higher number of lower esophageal reflux events on preoperative 24-hour pH testing, and were more likely to have persistent dysphagia after surgery. Fifty-nine percent of patients with cough had an alternative etiology for cough, compared to 36% of those without cough. Of the common alternative etiologies, only a history of postnasal drip occurred more frequently in those with cough. Complete resolution of cough occurred in 24 patients (64%), with another 10 (27%) reporting significant improvement. The average cough score improved significantly regardless of which coexisting etiology the patients may have had. Additionally, heartburn and regurgitation were improved in 94% of all patients.

Adult↗
PubMed1997

Parental reporting of childrens' coughing is biased.

Assessment of cough in the clinical setting as well as in community-based studies of respiratory epidemiology has relied on self-reports. To examine the accuracy and potential for systematic bias in reported cough during a field study, questionnaires administered to parents about their childrens' coughing were compared to overnight cough recordings performed in 145 homes in the community of Wallaceburg, Canada. Percentage agreement between reported and recorded coughing was low, with kappa statistics ranging from 0.02-0.10. Compared to non-smoking parents, smokers under-reported their childrens' coughing (p = 0.01). The association found between parental smoking and recorded coughing was biased towards the null when reported coughing was substituted for recorded coughing: the odds ratio between parental smoking and recorded coughing was 3.1 (95% CI: 1.1-8.8) whereas for reported coughing it was 0.6 (95% CI: 0.2-1.7), the difference in the odds ratios being significant at p = 0.03. When carrying out field surveys, consideration should be given to measuring cough in a subsample of the population in order to estimate the degree of bias inherent in the questionnaire-based results.

Child↗
PubMed1999

Cough and angiotensin II receptor antagonists: cause or confounding?

AIMS: Cough is one of the most frequent side effects associated with angiotensin converting enzyme inhibitors (ACEIs) but is not thought to be associated with losartan, an angiotensin II receptor antagonist (ARA). This study compares reports of cough with losartan and three ACEIs used in general practice. METHODS: Studies have been conducted for losartan, and three ACEIs enalapril, lisinopril and perindopril, using the technique of Prescription-Event Monitoring. Patients were identified using dispensed prescription data. Questionnaires were sent to patients' general practitioners 6 months after the date of first prescription. Cases of cough within the first 60 days of treatment with losartan resulting in withdrawal of the drug were followed up with additional questionnaires. Incidence rates for reports of cough were calculated. In order to reduce the impact of carry-over effects, rate ratios were calculated for first reports of cough between days 8 and 60 using losartan as the index drug. RESULTS: The cohort for each drug exceeded 9000 patients. Age and sex distributions and indications for prescribing the four drugs were similar. Cough was the most frequent reason for discontinuation of losartan and the most frequently reported event in the first month of treatment with this drug. When reports of cough between days 1-7 were excluded, rates of cough were significantly higher for the three ACEIs when compared with losartan (rate ratios 1.5, 4.8 and 5.7, all P<0.03). 101 patients had discontinued losartan due to cough. 91% of these had previously been prescribed an ACEI and 86% had previously experienced ACEI cough. CONCLUSIONS: Carry-over accounted for the observed excess of reports of cough with losartan. Rates of cough between days 8 and 60 were significantly higher for the three ACEIs compared with losartan. Confounding factors associated with comparative observational cohort studies are discussed.

Aged↗
PubMed2003

Influence of the rheological properties of airway mucus on cough sound generation.

OBJECTIVES: There have been several reports regarding the role of airway mucus in cough sound generation, but the properties of the mucus that influence cough sound generation remain unclear. The aim of this study was to elucidate the influence of the rheological properties of airway mucus on cough sound generation. METHODOLOGY: The acoustic properties of voluntary cough sounds from 15 patients with chronic productive cough and nine controls with dry cough were analyzed by dividing the energy envelope of the sounds into three phases and computing the root mean square values and the duration of each phase as a proportion of the total cough duration. The rheological properties of the airway mucus (yield value, ciliary transportability and spinability) were also measured. Differences between productive and dry cough sounds, and correlations between the acoustic properties of cough sounds and the rheological properties of the airway mucus, were analyzed. RESULTS: The acoustic properties of productive and dry cough sounds differed significantly (P < 0.05). The acoustic properties of second phase cough sounds correlated significantly with the yield value and ciliary transportability of the airway mucus (P < 0.05). CONCLUSIONS: The rheological properties of the airway mucus influenced cough sound generation.

Adult↗
PubMed1980

Effects of endotracheal intubation on normal cough performance.

To assess the effects of endotracheal intubation on normal cough function, the tracheas of eight healthy volunteers were intubated with a standard 8.0-mm-I.D. tube. Measurements were made of expiratory flow, transpulmonary pressure, and expired volume during a cycle of three successive bursts of maximum voluntary coughing initiated after inspiration to total lung capacity. Results following intubation were compared with findings with subjects breathing through a 25-mm-I.D. mouthpiece (control). Maximum cough pressures (Pmax) following tracheal intubation were similar to control values, but with the tube in place, airflow began well before Pmax was reached and did not cease fully between cough bursts. Flows at Pmax declined with each successive burst of coughing during both experimental conditions, but with tracheal intubation, the flows were significantly lower than control. Resistance to flow at Pmax increased with each successive cough and increased significantly above control during the third burst of coughing while the subjects' tracheas were intubated. The total volume of the three control coughs was 76 +/- 3 per cent of vital capacity. This was similar following intubation, although cough duration was significantly longer. These findings indicate that tracheal intubation does not impair ability to develop normal cough pressures despite preventing glottic closure. The normal timing of flow and pressure is disrupted such that flow occurs early--as in a forced expiratory maneuver, and the flow is not fully interrupted during the cough sequence. Flows are submaximal as a result of the resistance of the tube and continue to decline as the lung volume decreases and airways are compressed. Because the tube is noncollapsible, high flow rates may be necessary to achieve the linear velocities requireed for normal airway cleansing through the tube. Such flows may be achieved only during the initial cough after full inspiration.

Adult↗
PubMed2006

Role of the upper airways in patients with chronic cough.

PURPOSE OF THE REVIEW: Chronic cough can be caused by a number of factors, including infections, rhinosinusitis, asthma and environmental stimuli. This paper reviews recent findings and opinions regarding the role played by the upper airways in chronic cough. RECENT FINDINGS: Chronic cough has a significant impact on quality of life, which is more pronounced in women. In Western countries, the reported occurrence of rhinosinusitis in patient groups with chronic cough ranges from 8% to 81%. Allergic rhinitis is a risk factor for later development of asthma. In children, bronchiectasis is combined with upper airway abnormalities in the majority of cases. Increased expression of the capsaicin receptor subtype named 'transient receptor potential vanilloid-1', which correlates with capsaicin cough response, has been identified in patients with chronic cough. Patients with airway chemical sensitivity and chronic cough as one symptom have augmented capsaicin cough sensitivity that is related to changed levels of nerve growth factor in nasal lavage. SUMMARY: Involvement of the upper airways in chronic cough has been confirmed in several studies. However, there are considerable differences between different health centres in the occurrence of rhinosinusitis as a cause of chronic cough. In patients with chronic cough of various causes, a neurochemical alteration in both the upper and the lower airways appears to have taken place, followed by increased cough sensitivity.

Adolescent↗
PubMed2003

Effect of tartaric acid-induced cough on pulmonary function in normal and asthmatic humans.

OBJECTIVE: The laryngeal cough reflex and the laryngeal cough expiratory reflex are brainstem reflexes that protect the upper airway from significant aspiration. The purpose of this investigation was to examine the effects of tartaric acid-induced cough on pulmonary function in normal healthy and asthmatic individuals. DESIGN: Twenty healthy and 20 asymptomatic, medicated, asthmatic volunteers engaged in a two-part evaluation of pulmonary function testing. All 40 subjects were nonsmokers. The reflex cough test, a 20% solution of prescription-grade L-tartaric acid dissolved in 0.15 M NaCl solution, initiated the laryngeal cough expiratory reflex/laryngeal cough reflex. The solution was placed in a Bennett Twin nebulizer and inhaled as a microaerosol. Pulmonary function testing was with a Spiromate AS-600. Baseline pulmonary function testing was initially performed, followed by two separate inhalations of the reflex cough test. The pulmonary function testing was repeated 5 min after the second reflex cough test. RESULTS: Statistically significant changes seen after the reflex cough test included increases in the peak inspiratory flow in normal subjects (P = 0.004) and in the peak expiratory flow in asthmatic subjects (P = 0.014). No respiratory adverse events occurred after the reflex cough test. CONCLUSIONS: Explanations for these findings include the possibility that tartaric acid-induced cough produces central nervous system-mediated bronchodilatation, through the cough itself or by secondary mechanisms.

Administration, Inhalation↗
PubMed2005

Attenuating effect of H+K+ATPase inhibitors on airway cough hypersensitivity induced by allergic airway inflammation in guinea-pigs.

BACKGROUND: Gastrooesophageal reflux (GER) is a frequent cause of chronic cough. Several investigators have indicated that inhibitors of H(+)K(+)ATPase (proton pump inhibitors; PPIs) could relieve coughing via inhibition of acid reflux. However, we considered that PPIs might directly inhibit increased cough reflex sensitivity. OBJECTIVE: The present study was designed to examine whether PPIs directly inhibit antigen-induced increase in cough reflex sensitivity and to elucidate the mechanism. METHODS: Actively sensitized guinea-pigs were challenged with aerosol antigen (ovalbumin, OVA) and cough reflex sensitivity to inhaled capsaicin was measured 24 h later. The PPIs (omeprazole and rabeprazole) or the histamine H(2) blocker cimetidine were administered intraperitoneally 1 h before OVA challenge and before measuring cough reflex sensitivity, then bronchoalveolar lavage fluid (BALF) was immediately collected. The pH of the fluid obtained by bronchial washing was determined after examining the effect of rabeprazole on the cough response to capsaicin. RESULTS: The number of coughs elicited by capsaicin was significantly increased 24 h after challenge with OVA compared with saline, indicating antigen-induced increase in cough reflex sensitivity. Both PPIs dose dependently and significantly inhibited antigen-induced cough hypersensitivity. Omeprazole did not influence the antigen-induced increase in the total number of cells or ratio (%) of eosinophils in BALF. Cimetidine did not affect the antigen-induced cough hypersensitivity or cellular components of BALF. The pH of the bronchial washing fluid was significantly decreased in antigen-challenged animals. Rabeprazole did not affect the antigen-induced decrease in the pH of bronchial washing fluid. CONCLUSION: These findings show that PPIs, but not histamine H(2) blockers, can directly decrease antigen-induced cough reflex hypersensitivity, while the mechanism remains unclear.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1999

A prospective evaluation of esophageal testing and a double-blind, randomized study of omeprazole in a diagnostic and therapeutic algorithm for chronic cough.

OBJECTIVE: Recent studies suggest an association between chronic cough and gastroesophageal reflux. Our study aims were 1) to define the prevalence of acid reflux induced cough in the general community, 2) to examine the ability of esophageal testing to identify gastroesophageal reflux related cough, and 3) to assess the utility of omeprazole in a chronic cough algorithm. METHODS: Patients with chronic cough of unknown etiology, who were mostly from the community, were evaluated. Subjects underwent a chest x-ray, methacholine challenge test, and empiric trial of postnasal drip therapy, and completed daily cough symptom diaries subjectively evaluating cough frequency and severity on a graded scale of 0-4 (combined maximum 8). After excluding other causes of cough, the remaining patients underwent esophageal and pH testing. Those testing positive were randomized to omeprazole 40 mg b.i.d. or placebo for 12 weeks. Follow-up was 1 yr. RESULTS: A total of 71 patients were screened; 48 were excluded. Twenty-three patients were evaluated for gastroesophageal reflux disease; six (26%) were eventually determined to have an acid-related cough. Of these patients, 17 had a positive pH test, six (35%) of whom showed a striking improvement or resolution of their cough during omeprazole treatment which was sustained for up to 1 yr. Six had a negative pH test, none of whom responded to omeprazole therapy. No significant differences were seen between responders (n = 6) and nonresponders (n = 11) for demographic factors, baseline symptom frequency and duration, or physiological parameters (motility/pH). CONCLUSIONS: Acid-related chronic cough was present in 26% (six of 23) of patients evaluated for gastroesophageal reflux disease. Esophageal testing does not reliably identify patients with acid induced chronic cough responsive to proton pump inhibitor therapy. We suggest that the best diagnostic and therapeutic approach, after excluding asthma and postnasal drip syndrome, is empiric treatment for 2 wk with a high dose proton pump inhibitor.

Adolescent↗
PubMed2000

Cough threshold in reflux oesophagitis: influence of acid and of laryngeal and oesophageal damage.

BACKGROUND: Gastro-oesophageal reflux is often associated with cough. Patients with reflux show an enhanced tussive response to bronchial irritants, even in the absence of respiratory symptoms. AIM: To investigate the effect of mucosal damage (either oesophageal or laryngeal) and of oesophageal acid flooding on cough threshold in reflux patients. PATIENTS: We studied 21 patients with reflux oesophagitis and digestive symptoms. Respiratory diseases, smoking, and use of drugs influencing cough were considered exclusion criteria. METHODS: Patients underwent pH monitoring, manometry, digestive endoscopy, laryngoscopy, and methacholine challenge. We evaluated the cough response to inhaled capsaicin (expressed as PD5, the dose producing five coughs) before therapy, after five days of omeprazole therapy, and when oesophageal and laryngeal damage had healed. RESULTS: In all patients spirometry and methacholine challenge were normal. Thirteen patients had posterior laryngitis and eight complained of coughing. Twenty patients showed an enhanced cough response (basal PD5 0.92 (0.47) nM; mean (SEM)) which improved after five and 60 days (2.87 (0.82) and 5.88 (0.85) nM; p<0.0001). The severity of oesophagitis did not influence PD5 variation. On the contrary, the response to treatment was significantly different in patients with and without laryngitis (p = 0.038). In patients with no laryngitis, the cough threshold improved after five days with no further change thereafter. In patients with laryngitis, the cough threshold improved after five days and improved further after 60 days. Proximal and distal oesophageal acid exposure did not influence PD5. Heartburn disappeared during the first five days but the decrease in cough and throat clearing were slower. CONCLUSIONS: Patients with reflux oesophagitis have a decreased cough threshold. This is related to both laryngeal inflammation and acid flooding of the oesophagus but not to the severity of oesophagitis. Omeprazole improves not only respiratory and gastro-oesophageal symptoms but also the cough threshold.

Adult↗
PubMed2001

Temporal associations between coughing or wheezing and acid reflux in asthmatics.

BACKGROUND AND AIMS: The pulmonary symptoms of patients with lung disease may be ascribed to gastro-oesophageal reflux although a causal relationship between acid reflux and coughing or wheezing has not been proved. Does cough cause reflux or does reflux cause cough? The aim of this study was to evaluate 24 hour oesophageal pH tracings of asthmatics with gastro-oesophageal reflux to determine the temporal association between acid reflux and coughing or wheezing. METHODS: The oesophageal tracings of 128 asthmatics from the outpatient clinics who underwent oesophagogastroduodenoscopy, oesophageal manometry, and 24 hour oesophageal pH monitoring were analysed. Three possible temporal relationships between the occurrence of acid reflux and the occurrence of coughs or wheezes were evaluated: (1) pulmonary symptoms preceding reflux; (2) reflux preceding pulmonary symptoms; and (3) unrelated occurrence of both events. RESULTS: Of 128 asthmatics, 53 recorded five or more coughs and 19 recorded three or more wheezes during the 24 hour recording period. Mean acid contact time was similar in asthmatics with and without pulmonary symptoms (12.2 (1.2)% v 10.4 (0.6)%). Of all coughs and wheezes, 46% and 48%, respectively, were associated with acid reflux. For the individual asthmatic, the likelihood of reflux induced coughing increased as the number of coughs increased. CONCLUSIONS: Half of all coughs and wheezes in asthmatics are associated with acid reflux into the oesophagus. While an occasional coughing episode can lead to reflux, it is rather the reflux episode in the vast majority of instances that leads to cough.

Asthma↗