| pA2 online © Copyright 2004 The British Pharmacological Society |
145P
University of Newcastle Winter Meeting December 2004 |
The combined oral contraceptive pill is associated with a significant reduction in the risk of asthma in teenage girls N. Krishnamoorthy1, A. R. Amri, C. R. Simpson1, R. Milne1, P. J. Helms2 & J.S. Mclay. Departments of Medicine and Therapeutics, 1General Practice and 2Child Health. The University of Aberdeen, Aberdeen. |
|
Print abstractIn girls, the development and severity of asthma has been associated with the menarche, and recently it has been suggested that the administration of the oral contraceptive pill (OCP), may have an influence on both the number and severity of asthma attacks. However, there is as yet no consensus as to whether the OCP actually improves of exacerbates the symptoms of asthma in young women [1–3]. Last year we reported that use of the OCP by girls aged 16 years and less was associated with a significant reduction in the use of anti-asthma treatments [4]. The aim of this study was to compare the frequency of OCP use by young women currently diagnosed as asthmatic when compared with an age and practice matched cohort of non asthmatic subjects.
A diagnosis of asthma was assumed if subjects were prescribed both an inhaled steroid and bronchodilator during the study year, equivalent to stage 2 of the British Thoracic Guidelines. Girls aged 16 years or less prescribed both therapies were identified and OCP and concomitant prescribing assessed in 21 475 females aged 10-16 years, for the year Nov 1st 2001-Oct 31st 2002. Data was retrieved from 160 general practices registered with the Scottish Programme for Improving Clinical Effectiveness in Primary Care (SPICEpc). All drug prescriptions for the OCP were assessed in asthmatic females and an identical age and practice matched asthma free group and odds ratios calculated using logistic regression. During the study year 2049 females under the age of 17 years were prescribed dual anti-asthma medication by their GP and assumed to have a diagnosis of asthma. Comparison with an age and practice matched control group confirmed that a diagnosis of asthma was associated with a significant reduction in the number of individuals prescribed the OCP (OR 1.28, CI 1.0, 1.64, p = 0.04). A further age and practice matched comparison of the 1897 girls aged 16 years or less prescribed the OCP during the study year, confirmed that OCP use was associated with a significant reduction in the use of all anti-asthmatic drugs (OR 1.35, CI 1.12, 1.62, p < 0.002), anti-allergy treatments (OR 1.34, CI 1.12, 1.61, p < 0.002) and oral antibacterial agents (OR 1.17, CI 1.03, 1.33, p < 0.02).
The results of this retrospective cross sectional case controlled study confirm that for young women a diagnosis of asthma is associated with significantly less OCP use and that a prescription for the OCP is associated with significantly fewer females on concomitant anti-asthma, anti-allergy and antibiotic medication.
1. D’Souza RE, Guillebaud J. Baillieres Best Pract Res Clin Obstet Gynaecol 2002; 16: 133.
2. Forbes L. Thorax 1999; 54: 265.
3. Strinic T, et al. Fertil Steril 2003; 79: 1070.
4. Krishnamoorthy N, et al. Br J Clin Pharmacol 2004; 57: 665.