Atrial fibrillation is the most prevalent cardiac arrhythmia with a high risk of ischemic stroke. Thromboprophylaxis plays a key role in prevention of cardioembolic and non-cardioembolic events. Oral antithrombotic drugs are most often used to reduce hypercoagulable state. Patients may suffer from both under- and overtreatment compromising the outcomes. Medication peculiarities at large are well-known and widely debated. Non-adherence to antithrombotic drug regimen poses a significant risk of stroke. There is a pressing need for more detailed delineation of risk factors, namely by incorporation of the letter “N” (meaning “Non-adherence to drug therapy”) into the well-known risk score alphanumeric display: CHA2DS2N-VASc. Better delineation of risk factors related to antithrombotic treatment as well as those related to treatment for congestive heart failure, hypertension, diabetes are desirable. Similarly, the bleeding risk score formula HAS-BLED might be improved by an additional risk factor, marked as the symbol “E”, meaning “Excessive antithrombotic dosing” i.e. HAS-BLEDE. Improved formulas would help raise the predictive scores value and awareness for clinicians facing the problem of non-adherence to treatment regimen. If patients properly followed the prescribed drug therapy regimen it would potentially reveal that we already have ideal or near ideal antithrombotic drug(s). These drugs, herein non-specified, are widely used, but due to non-adherence they are not categorized as the best ones. That is why considerable efforts are focused on continued research and new developments.