ABSTRACT
BACKGROUND: This study characterized a cohort of chronic obstructive pulmonary disease (COPD) patients on maintenance bronchodilator monotherapy for ≥6 months to establish their disease burden, measured by health care utilization. METHODS: Data were extracted from the UK Clinical Practice Research Datalink and linked to Hospital Episode Statistics. The monotherapy period spanned the first prescription of a long-acting ß2-adrenergic agonist or a long-acting muscarinic antagonist until the end of the study (December 31, 2013) or until step up to dual/triple therapy, for example, addition of another long-acting bronchodilator, an inhaled corticosteroid, or both. A minimum of four consecutive prescriptions and 6 months on continuous monotherapy were required. Patients <50 years old at first COPD diagnosis or with another significant respiratory disease before starting monotherapy were excluded. Disease burden was evaluated by measuring patients' rate of face-to-face interactions with a health care professional (HCP), COPD-related exacerbations, hospitalizations, and referrals. RESULTS: A cohort of 8,811 COPD patients (95% Global initiative for chronic Obstructive Lung Disease stage A/B) on maintenance monotherapy was identified between 2002 and 2013; 45% of these patients were still on monotherapy by the end of the study. Median time from first COPD diagnosis to first monotherapy prescription was 56 days, while the median time on maintenance bronchodilator monotherapy was 2 years. The median number of prescriptions was 14. On average, patients had 15 HCP interactions per year, and one in ten patients experienced a COPD exacerbation (N=8,811). One in 50 patients were hospitalized for COPD per year (n=4,848). CONCLUSION: The average monotherapy-treated patient had a higher than average HCP interaction rate. We also identified a large cohort of patients who were stepped up to triple therapy despite a low rate of exacerbations. The use of the new class of long-acting muscarinic antagonist/long-acting ß2-adrenergic agonist fixed-dose combinations may provide a useful step-up treatment option in such monotherapy patients, before the use of inhaled corticosteroids.
Subject(s)
Adrenergic beta-2 Receptor Agonists/administration & dosage , Bronchodilator Agents/administration & dosage , Health Resources/statistics & numerical data , Lung/drug effects , Muscarinic Antagonists/administration & dosage , Pulmonary Disease, Chronic Obstructive/drug therapy , Administration, Inhalation , Adrenal Cortex Hormones/administration & dosage , Databases, Factual , Disease Progression , Drug Prescriptions , Drug Therapy, Combination , Drug Utilization Review , Female , Hospitalization , Humans , Lung/physiopathology , Male , Middle Aged , Office Visits/statistics & numerical data , Practice Patterns, Physicians' , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/physiopathology , Referral and Consultation/statistics & numerical data , Retrospective Studies , Time Factors , Treatment Outcome , United KingdomABSTRACT
Prostaglandin E(2) (PGE(2)) is an inflammatory mediator implicated in several gastrointestinal pathologies that cause diarrhoea. The aim of this study was to establish the contributions of the four different EP receptors (EP(1-4)) to PGE(2)-induced anion secretion in human and mouse colon mucosa. Electrogenic anion secretion (short-circuit current; I(sc)) was measured across colonic mucosae or T84 monolayers placed in Ussing chambers in response to EP receptor agonists and antagonists. PGE(2) and PGE(1)-alcohol increased I(sc) in human colon mucosa, T84 epithelia and mouse colon mucosa, and these responses were inhibited by the EP(4) receptor antagonist, GW627368X alone. In addition, the EP(2) agonist, butaprost increased I(sc) in all three preparations and these responses were inhibited by the non-selective EP(1,2,3) receptor antagonist, AH6809 but not by GW627368X. Conversely, responses mediated by EP(1) and EP(3) receptors were not observed in human colon or T84 monolayers. However, in mouse colon mucosa the EP(3)-preferring agonist, sulprostone reduced I(sc), indicative of G(iα)-signalling. Taken together these results indicate that PGE(2)-induced ion secretion is mediated predominantly by G(s)-coupled EP(4) receptors and also by EP(2) receptors in human mucosa. Furthermore, tumour necrosis factor alpha (TNFα) and interleukin 1beta (IL1ß) increased I(sc) and these responses were also inhibited by the EP(4) receptor antagonist in human colon mucosa. This study establishes the EP receptor pharmacology present in human epithelial preparations, and suggests that EP(4) receptors may be a therapeutic target for the treatment of secretory diarrhoea where PGE(2) is implicated in the aetiology.
