Drug interactions with new oral anticoagulants in elderly patients.

This review attempts to summarise what is known about Drug-drug interactions (DDIs) of the new oral anticoagulants (NOACs) in elderly patients. The literature was searched for: 'CYP3A4', 'CYP2C9', 'P-glycoprotein', 'acetylsalicylic-acid', 'non-steroidal anti-inflammatory', 'clopidogrel', 'ticagrelor', 'prasugrel' and 'dabigatran', 'rivaroxaban', 'edoxaban', or 'apixaban'. 'Elderly' was defined as ≥75 years. Areas covered: Publications about DDIs of NOACs were found for 35% of 140 potentially interacting drugs. Reports about DDIs of cardiovascular drugs, were most frequent, followed by anti-infective and nervous system drugs. Reports about elderly were found for only 47 patients. DDIs were reported most frequently in association with dabigatran. Dabigatran is the only NOAC interacting with proton-pump-inhibitors. Expert commentary: Dabigatran was the first NOAC approved, so it is not possible to determine whether the higher number of reports about DDIs with dabigatran compared with other NOACs is due to a higher rate of DDIs or to the length of time during which this drug has been in use. Most of the data is derived from subgroup-analyses of trials, sponsored by NOAC manufacturers, consequently there is a lack of independent data. Because of the scarcity of data, the clinical relevance of DDIs of NOACs is uncertain at present, especially in elderly patients.