Caffeine-containing medicines increase the risk of hemorrhagic stroke.

BACKGROUND AND PURPOSE Research on the relationship between caffeine-containing medicines (CCMs) and the risk of hemorrhagic stroke (HS) is sparse. The aim of this study is to evaluate the association between CCMs and the risk of HS. METHODS We performed a multicenter case-control study in South Korea, from 2002 to 2004. A total of 940 patients with nontraumatic acute HS, aged 30 to 84 years without a history of stroke, 940 community, and 940 hospital controls, age and sex matched to each case, were included. We obtained information on all medications taken in the 14 days before the date (index date) and time of stroke onset (zero-time) for case subjects or matched zero-time for control subjects. Exposure to CCMs was defined by use on the index date before zero-time or during the preceding 3 days. The adjusted odds ratios and their 95% confidence intervals (CIs) were estimated by conditional logistic regression. RESULTS The adjusted odds ratio for the association between the use of CCM and risk for HS was 2.23 (95% CI, 1.41-3.69) for all HS, 2.24 (95% CI, 1.08-4.66) for subarachnoid hemorrhage, and 2.49 (95% CI, 1.29-4.80) for intracerebral hemorrhage. Stratified by daily coffee intake, adjusted odds ratio of CCMs for HS was 2.95 (95% CI, 1.45-5.98) for those who did not drink coffee on a daily basis. CONCLUSIONS These results suggest that use of CCMs is associated with increased risk of HS, both subarachnoid hemorrhage and intracerebral hemorrhage.