It is well known that the greatest risk of atrial fibrillation is the increased risk of thromboembolism (including stroke, peripheral artery embolism, etc.). The importance of receiving oral anticoagulants to prevent embolic events based on the risk of thromboembolism cannot be overstated. With the introduction of new oral anticoagulants (NOACs) for patients requiring anticoagulation therapy, more and more patients with non-valvular atrial fibrillation are receiving NOACs for the prevention of thromboembolic events due to their high safety profile and ease of use (unlike warfarin, which requires adjustment of drug doses based on regular and frequent monitoring of coagulation parameters). However, a very common problem in daily practice is the issue of dosing errors in the use of NOACs, such as missed doses and overdoses. Usually, patients who notice dosing problems during NOACs should contact their usual hospital for consultation with a knowledgeable physician or a dedicated atrial fibrillation follow-up center. To prevent dosing problems such as missed doses or overdoses, patients can use a special medication box with clearly marked dosing times (note that dabigatran should not be removed from its original packaging until it has been taken). Missed doses As a general rule, if the missed dose does not exceed 50% of the time between doses, a replacement dose can be taken immediately. For example, if a dose of rivaroxaban, apixaban or edoxaban is missed and the missed dose is found to be within 12 hours of the previous dose, a dose of rivaroxaban, apixaban or edoxaban can be taken as soon as possible. If a missed dose of dabigatran is found to have been missed no more than 6 hours after the previous dose was due, a single dose of dabigatran may be given as soon as possible. Alternatively, for patients at high risk of stroke and low risk of bleeding, a single dose of NOACs can be made up before the next scheduled dose. If the forgotten time is more than 50% of the time between doses or if the patient is not at high risk of stroke, the missed dose of this NOACs can simply be ignored until the next dose time to take the drug. If a patient mistakenly takes a double dose of dabigatran on one occasion, the patient may stop taking one dose at the next dose and restart the planned twice-a-day dabigatran dose 24 hours later. If a double dose of rivaroxaban, apixaban, or edoxaban was mistakenly taken on a single occasion, you do not need to stop taking the dose at the next dose and continue to take rivaroxaban, apixaban, or edoxaban according to the original dosing schedule. Unable to confirm whether or not to take a certain dose Some elderly people are unable to confirm whether or not to take a certain dose because of their old age and poor memory. In such cases, NOACs (rivaroxaban, apixaban or edoxaban) taken once a day are handled differently than NOACs (dabigatran) taken twice a day. In the case of dabigatran, it is not recommended that an additional dose be administered and that the dose continue to be taken at the next time.