Prescribing for osteoporosis following the use of inhaled and oral glucocorticoids in general practice

Abstract

Aims: Systemic absorption from inhaled glucocorticoids may lead to bone loss. We determined the extent to which their use alone and in addition to short courses of oral glucocorticoids was associated with increased prescribing for osteoporosis in a large general practice population.

Methods: In a cohort study with follow-up of co-prescribing of antiosteoporotic drug therapy in the Irish national prescribing database (1.1 million people over 16 years), we identified 32 081 patients who received inhaled glucocorticoids alone during a 12-month period (following an identical lead-in period). We determined the odds ratio (OR), adjusting for age and gender for the co-prescription of bisphosphonates or other antiosteoporotic therapy with inhaled glucocorticoids by logistic regression.

Results: The adjusted OR (95% confidence interval) for co-prescribing of bisphosphonates and all inhaled glucocorticoids was 1.87 (1.71, 2.04); 1.58 (1.41, 1.78) for inhaled beclomethasone, 2.11 (1.75, 2.54) for inhaled budesonide and 3.29 (2.65, 4.1) for inhaled fluticasone. The ORs were significantly increased when patients who also received oral glucocorticoids were included and greater still in those under 45 years: 14.03 (10.6, 18.6). The results remained significant when the effects of comorbidity were adjusted for. The odds of receiving bisphosphonate therapy increased linearly with increasing exposure to inhaled glucocorticoids during the study period.

Conclusions: Treatment with inhaled glucocorticoids in general practice is associated with an increased risk of co-prescribing for antiosteoporotic therapy in a potency- and a dose-related manner. Exposure to a course of oral glucocorticoids doubles this risk. These results suggest that the systemic effects on bone mineral density from using inhaled glucocorticoids may be clinically relevant but may also reflect prescribers' concerns for the development of osteoporosis in these patients.

Figure 1

Flow diagram showing numbers of patients included in the study (N, % on any antiosteoporotic therapies)

Figure 2

Log (odds ratio: 95% CI) for the co-prescription of bisphosphonate (n = 533) medication related to the exposure (as estimated by the daily defined dose, DDD per month) to inhaled corticosteroids and oral corticosteroids (P < 0.001 for trend). Seventy-five DDDs per month for inhaled corticosteroids = 2000 µg; 150 DDDs per month for inhaled corticosteroids = 4000 µg.