Question

When caring for a patient who has started anticoagulant therapy with Coumadin, the nurse explains to the patient not to expect therapeutic benefits for

a) 2 to 3 days

b) 1 week

c) at least 2 hours

d) the first 24 hours

2)A client is on anticoagulant therapy. The blood test results indicate a prothrombin time (PT) of 25 seconds (3 times the control) and an INR of 4.5. The nurse would expect the physician to order which medication

a) protamine sulfate

b) coumadin

c) vitamin K

d) no medication since the blood tests are WNL

Answer 1

1)a) 2-3 days

Warfarin is a vitamin k antagonist it inhibit the synthesis of vitamin k dependent clotting factors.

Warfarin begins to reduce the blood clotting in 24 hr after the initial dose. But full anti thrombotic effect may not present until 3 - 5 days.so it take minimum 3 days to get a therapeutic benefit.

Single dose effect last for two to five days. It has a long half life. So it remains effective for several days after stopping the drug also.

2) c ) vitamine K

Higher prothrombin time and INR indicates, blood takes longer time to get clot.

By increasing the vitamin k intake prothrombin time and INR level can be dropped.Vitamine k is needed for making prothrombin and other clotting factor.

Warfarin increases the prothrombin time and protamine sulphate is specifically used for heating over dose.

Normal range of prothrombin time is 11- 13.5 sec and INR is 1.1 or below for normal person and patients on anticoagulants like warfarin is 2- 3.