No standard dosage of warfarin will work for all people or even for the same person in all situations. Dosing for this medication must be individualized, and many factors can affect the amount prescribed, including dietary changes and drug interactions. Frequent dosing adjustments are often necessary, as taking too little or too much can lead to life-threatening problems.
The dose of warfarin sodium (Coumadin®, Jantoven®) your healthcare provider recommends will vary, depending on how you respond to the medication (this is monitored using regular blood tests). As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
Warfarin is not dosed like most other medications. While it can be a life-saving drug, unfortunately, the side effects can be life-threatening. Taking too little increases your risk for blood clots and strokes, and taking too much increases your risk for dangerous internal bleeding. Even tiny dosing changes can have a large effect. In addition, an amount that is safe and effective for one person may be too high or too low for another person.
Therefore, dosing for warfarin must be individualized. It is not necessarily related to body weight, and many factors affect the amount prescribed. Keep in mind that a dosage that works well today may not be appropriate next week. Sometimes, frequent dosing adjustments are necessary, although ideally, most people will achieve a somewhat steady dose.