normal inr time
International normalized ratio (INR): 0.8-1.1. The warfarin (Coumadin) dose is changed so that the prothrombin time is longer than normal (by about 1.5 to 2.5 times the normal value or INR values 2 to 3).Prothrombin times are also kept at longer times for people with artificial heart valves, because these valves have a high chance of causing clots to form. PT test may also be called an INR test. INR (international normalized ratio) stands for a way of standardizing the results of prothrombin time tests, no matter the testing method.