Introduction
The following table provides a summary of the results obtained using the PT, APTT, Fibrinogen and Thrombin Time in various disorders.
Table 3 summarizes the results of screening tests of patients on anticoagulant regimen.
Table 3. Effect of Anticoagulants on Conventional Coagulogram.
| Drug | PT | APTT | TT | Fibrinogen | Notes |
| Vitamin K Antagonists | ↑ | ↑/N | No significant effect | No effect | The APTT may be prolonged in patients with INR > 2.0 |
| Unfractionated
Heparin (UFH) |
↑ | ↑ | ↑ | No effect | |
| Low Molecular Weight Heparin (LMWH) | No effect | No effect | May be prolonged | No effect | |
| Dabigatran | ↑ – test has low sensitivity and results vary with thromboplastin used in the test | ↑ in a curvilinear manner but vary with reagents used in the test | ↑ | No effect or factiously low | A normal TT excludes significant Dabigatran levels |
| Apixaban | ↑ | ↑ | No significant effect | No significant effect | |
| Edoxaban | ↑ | ↑ | No significant effect | No significant effect | |
| Rivaroxaban | ↑ – results vary with the specific thromboplastin used in the test | No significant effect | No significant effect | ||
| Fondaparinux | No effect | No clinically significant effect | No significant effect | No significant effect | |
| Bivalirudin |