EN
In Estonia, HMG-CoA reductase inhibitors are
widely used to modify lipid levels but there are no current
data on additional medicines prescribed alongside the
statins. The aim of this study was to identify the frequency
of potential clinically relevant interactions at a national
level among an outpatient population treated with statins
between January and June 2008, based on the prescription
database of the Estonian Health Insurance Fund. This retrospective
prevalence study included 203,646 outpatients
aged 50 years or older, of whom 29,367 received statin
therapy. The study analysed individuals who had used at
least one prescription medicine for a minimum of 7 days
concomitantly with statins. Potential drug interactions
were analysed using Epocrates online, Stockley’s Drug
Interactions, and the drug interaction database developed
in Estonia. Statins metabolised by the CYP3A4 isoenzyme
were prescribed to 64% of all statin users. Medicines
known to have potentially clinically significant interactions
with statins were prescribed to 4.6% of patients. The drugs prescribed concomitantly most often with simvastatin
were warfarin (5.7%) and amiodarone (3.9%),
whereas digoxin (1.2%) and ethinylestradiol (2%) were
prescribed with atorvastatin. Potential interactions were not detected in the treatment
regimens of rosuvastatin, pravastatin, and fluvastatin
users.