Asthma severity and susceptibility to air pollution.

Exacerbations of asthma have been associated with exposure to ozone or particles with a 50% cut-off aerodynamic diameter of 10 microm (PM10). We postulated in this study that the association of summertime air pollution (i.e. ozone and PM10) with acute respiratory symptoms, medication use and peak expiratory flow differs among patients grouped according to asthma severity. During the summer of 1995, effects of ambient air pollution on these parameters were studied in a panel of 60 nonsmoking patients with intermittent to severe persistent asthma. These patients were recruited from our Pulmonary Out-patient Clinic. Subgroup analysis was performed on the degree of hyperresponsiveness and lung steroid use before the start of the study, as indictors for the severity of asthma. Associations of the parameters studied with ozone, PM10, nitrogen dioxide (NO2), sulphur dioxide (SO2) and black smoke were evaluated using time series analysis. Several episodes with increased summertime air pollution occurred during the 96 day study period. Eight hour average ozone concentrations exceeded the World Health Organization (WHO) Air Quality Guidelines (120 microg x m(-3)) on 16 occasions. Daily mean levels of PM10 were moderately elevated (range 16-98 microg x m(-3)). Levels of the other measured pollutants were low. There was a consistent, positive association of the prevalence of shortness of breath (maximal relative risk (RRmax) 1.18) with ozone, PM10, black smoke and NO2. In addition, bronchodilator use was associated with both ozone and PM10 levels (RRmax 1.16). Stratification by airway hyperresponsiveness and steroid use did not affect the magnitude of the observed associations. No associations with peak expiratory flow measurements were found. We conclude that the severity of asthma is not an indicator for the sensitivity to air pollution.

Utilization patterns of non-steroidal anti-inflammatory drugs in an open Dutch population.

Non-steroidal anti-inflammatory drugs represent an important drug class in ambulatory care. A utilization study among half a million persons showed that 8.6% could be identified as having used one or more non-steroidal anti-inflammatory drugs (excluding salicylates) in 1987. Data were drawn from a representative sample of pharmacy records which comprise full medication histories of individual patients. Overall utilization of non-steroidal anti-inflammatory drugs was 10.8 defined daily doses/(1000 persons.day). Approximately three quarters of the patients are 'incidental' users and receive non-steroidal anti-inflammatory drugs for a relatively short time (30 days or less). Patients who were identified as 'regular' (31-210 days of therapy) and 'heavy' (greater than 210 days of therapy) users, accounted for 21.2% respectively 4.8% of all users. 'Heavy' users are responsible for 17.3% of all non-steroidal anti-inflammatory drug prescriptions. Especially the elderly and females are prone to be 'heavy' users. Five drugs account for 90.4% of all prescriptions (diclofenac, ibuprofen, naproxen, piroxicam, indomethacin). A total of 71.1% of the patients with more than one prescription for non-steroidal anti-inflammatory drugs switched in therapy. There are two classes of concomitant drug use especially relevant with respect to detecting non-steroidal anti-inflammatory drugs-associated risks: H2 blockers and antacids (belonging to anatomical therapeutic and chemical anatomic class A) and diuretics (belonging to anatomical therapeutical chemical anatomic class C). More than half of the 'heavy' users showed concomitant use of drugs in these classes.