Test Code 8847
CPT Code(s) 85610
Methodology Photo-optical Clot Detection
Limitations Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: prolonged; Heparin (UFH or LMWH): little to no effect (reagent contains a heparin neutralizer); Dabigatran or Argatroban (Thrombin Inhibitors): normal to prolonged; Rivaroxaban or Apixaban (Factor Xa Inhibitors): prolonged.
Reference Range(s)
PT 9.0-11.5 sec
INR
| Reference range | 0.9-1.1 |
| Moderate – intensity Warfarin therapy | 2.0 – 3.0 |
| Higher – intensity Warfarin therapy | 3.0-4.0 |
Clinical Significance Screening test for abnormalities of coagulation factors that are involved in the extrinsic pathway. Also used to monitor effects of Warfarin therapy and to study patients with hereditary and acquired clotting disorders.
Test FAQ
Prothrombin Time with INR
Alternative Name(s) PT
Prothrombin Time with INR Collection Guide
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