A Quick Test On Pharmacotherapy Of HIT
(313).jpg "A Quick Test On Pharmacotherapy Of HIT - Quiz")
Pharmacotherapy is just like therapy, but one uses pharmaceutical drugs. Patients with HIT are at high risk for thrombotic events and are mostly prescribed to undergo pharmacotherapy. As a pharmacology student, what do you know about the process as a whole? Take up the quick quiz below on the pharmacotherapy of HIT topic and get to refresh your memory. All the best!
- 1.
Which of the following is valid for HAT?
- A.
Onset is within 4 days
- B.
Onset is usually 5 to 10 days
- C.
Platelet count typically 100-150
- D.
Platelet count typically 20-150
- E.
Incidence is more common than HIT
- F.
Incidence is less common than HIT
- G.
Recovery is longer than with HIT
- H.
Recovery is shorter than with HIT
- I.
Caused by direct drug induced platelet aggregation
- J.
Cause is immune-mediated
Correct Answer(s)
A. Onset is within 4 days
C. Platelet count typically 100-150
E. Incidence is more common than HIT
H. Recovery is shorter than with HIT
I. Caused by direct drug induced platelet aggregationExplanation
HAT (Heparin-Associated Thrombocytopenia) is a condition characterized by a decrease in platelet count due to the use of heparin. The onset of HAT typically occurs within 4 days after starting heparin treatment. The platelet count in HAT is typically between 100-150. HAT has a higher incidence compared to HIT (Heparin-Induced Thrombocytopenia). The recovery time for HAT is shorter than with HIT. HAT is caused by direct drug-induced platelet aggregation, meaning that the heparin directly affects the platelets.Rate this question:
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- 2.
IgG antibodies + thrombocytopenia without thromboembolic events are:
- A.
Seroconversion
- B.
Isolated HIT
- C.
Heparin-induced thrombocytopenia thrombosis syndrome (HITTS)
Correct Answer
B. Isolated HITExplanation
Isolated HIT refers to the presence of thrombocytopenia without thromboembolic events in a patient who has developed IgG antibodies. This condition occurs as a result of an immune response to heparin, a medication used to prevent blood clotting. The antibodies formed can bind to platelets, leading to their destruction and causing a decrease in platelet count. However, in isolated HIT, there is no development of thromboembolic events, which are blood clots that can block blood vessels.Rate this question:
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- 3.
IgG antibodies to heparin-platelet factor 4 complexes but not thrombocytopenia is:
- A.
Seroconversion
- B.
Isolated HIT
- C.
HITTS
Correct Answer
A. SeroconversionExplanation
Seroconversion refers to the process in which an individual's blood serum changes from being negative to positive for a specific antibody. In this case, the presence of IgG antibodies to heparin-platelet factor 4 complexes indicates a seroconversion, meaning that the individual has developed antibodies against these complexes. However, the absence of thrombocytopenia suggests that the individual does not have HIT (heparin-induced thrombocytopenia) or HITTS (heparin-induced thrombocytopenia and thrombosis syndrome).Rate this question:
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- 4.
If we suspect HIT, check the patient's serum for HIT antibodies, assess for thrombosis, and diagnose a patient with HIT; Which of the following should we do next?
- A.
Give the patient FULL therapeutic doses of an alternative anticoagulant such as a LMWH.
- B.
Give the patient FULL therapeutic doses of an alternative anticoagulant, such as lepirudin, argatroban, or fondaparinux.
- C.
If a thrombus is found, begin warfarin only after platelet count has substantially recovered (>150k).
- D.
Consider platelet transfusion.
Correct Answer(s)
B. Give the patient FULL therapeutic doses of an alternative anticoagulant, such as lepirudin, argatroban, or fondaparinux.
C. If a thrombus is found, begin warfarin only after platelet count has substantially recovered (>150k).Explanation
– No, spontaneous bleeding during HIT is uncommon
– Platelet transfusions could possible increase thrombotic risk
-LMWHs are relatively contraindicated in HIT
-Why not just use warfarin?
– Early on, warfarin increases the risk of thrombosis in acute HIT
causing limb gangrene and skin necrosis
– Delay initiation of warfarin until the platelet count has substantially
recovered (e.g. >150K)
– Overlap warfarin (dosesRate this question:
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- 5.
Which of the following is NOT a risk factor for developing HIT?
- A.
Recent heparin (past 100 days).
- B.
Heparin duration > 2 days
- C.
UFH > LMWH
- D.
Female > male
- E.
Post surgery
Correct Answer
B. Heparin duration > 2 daysExplanation
heparin duration > 4 days....platelet count fall typically begins between days 5-10, which thrombocytopenia usually reached by day 7-14; thus, each day of heparin use beyond day 5 and to day 14, increases the risk of HITRate this question:
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- 6.
IgG antibodies + thrombocytopenia + thromboembolism is:
- A.
Seroconversion
- B.
Isolated HIT
- C.
HITTS
Correct Answer
C. HITTSExplanation
HITTS stands for Heparin-Induced Thrombocytopenia and Thrombosis Syndrome. This condition occurs when a person develops antibodies against heparin, a blood thinner, leading to low platelet count (thrombocytopenia) and the formation of blood clots (thromboembolism). The presence of IgG antibodies, along with the symptoms of thrombocytopenia and thromboembolism, suggests HITTS. Seroconversion refers to the change in antibody status from negative to positive, and isolated HIT refers to the development of thrombocytopenia without thromboembolism.Rate this question:
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- 7.
First, heparin binds to platelet factor 4 tetramers that are secreted by platelet, which form an antigenic complex. What happens immediately after this?
- A.
Heparin: PF4 complex binds to the anchored IgG Ab and crosslinks with other IgG Abs on the platelet, producing additional PF4 which perpetuates further platelet activation.
- B.
B lymphocytes generate IgG antibodies to the complex, which then bind to the Fc receptors on platelet cell surfaces.
- C.
The platelets release PF4 and microparticles, which are thrombogenic and promote thrombin production.
Correct Answer
B. B lymphocytes generate IgG antibodies to the complex, which then bind to the Fc receptors on platelet cell surfaces.Explanation
After heparin binds to platelet factor 4 tetramers, B lymphocytes generate IgG antibodies to the complex. These IgG antibodies then bind to the Fc receptors on platelet cell surfaces. This binding of IgG antibodies to the Fc receptors further activates the platelets, perpetuating platelet activation and promoting thrombin production.Rate this question:
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- 8.
Which of the following would help us diagnose HIT?
- A.
Platelet counts fall below
- B.
Median platelet count is about 55x10^9/L
- C.
Most commonly thrombocytopenia occurs 5-10 days after heparin exposure.
- D.
IgG antibodies to heparin-PF4 complexes.
Correct Answer(s)
A. Platelet counts fall below
B. Median platelet count is about 55x10^9/L
C. Most commonly thrombocytopenia occurs 5-10 days after heparin exposure.
D. IgG antibodies to heparin-PF4 complexes.Explanation
Platelet counts falling below normal levels, a median platelet count of about 55x10^9/L, thrombocytopenia occurring 5-10 days after heparin exposure, and the presence of IgG antibodies to heparin-PF4 complexes are all indicators that can help diagnose HIT (Heparin-Induced Thrombocytopenia).Rate this question:
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- 9.
HIT can occur even if platelets do not fall below 100 x 10^9/L.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
In 20% of patients, platelets do not fall this much.Rate this question:
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- 10.
If a patient has kidney failure, which is the best agent to use?
- A.
Lepirudin
- B.
Fondaparinux
- C.
Argatroban
Correct Answer
C. ArgatrobanExplanation
Argatroban is the best agent to use in a patient with kidney failure. This is because argatroban is a direct thrombin inhibitor that can be used as an anticoagulant in patients with renal impairment. It is metabolized by the liver, so it does not require renal excretion, making it a suitable choice for patients with kidney failure who may have impaired renal function. Lepirudin and fondaparinux, on the other hand, are primarily eliminated by the kidneys and may require dose adjustments or careful monitoring in patients with renal impairment.Rate this question:
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Mar 22, 2023Quiz Edited by
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May 16, 2011Quiz Created by
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