The effects of inhaled respiratory drugs on the risk of stroke: A nested case-control study

Although there have been concerns that inhaled long-acting muscarinic antagonists increase the risk of stroke, controversies exist. We investigated whether respiratory drugs including long-acting muscarinic antagonists are associated with the risk of stroke. A nested case-control study using the nationwide insurance claims database of the Health Insurance Review and Assessment Service (Seoul, Republic of Korea) was conducted. Overall, 16,354 stroke cases and 74,451 matched (up to 1:5) controls were identified from 809,684 subjects without acute major cardiovascular events in the past year between January 1, 2010, and December 31, 2011. To determine whether the use of inhaled respiratory drugs is associated with the risk of stroke, conditional logistic regression analysis adjusted by comorbidities, cardiovascular drugs and healthcare utilization was performed. After adjusting for covariates, there were no statistically significant effects of the inhaled drugs on stroke incidence, except for inhaled corticosteroids without a long-acting β2-agonists, which was significantly associated with hemorrhagic stroke. Inhaled respiratory medications, including long-acting muscarinic antagonists, did not affect the risk of stroke in the inhaled respiratory drug users.