What specific labs should be monitored for heparin? (3) Why?
Monitor for bleeding and HIT
When do you dose-adjust renally for heparin?
No renal dose-adjustments
What is the PTT goal for heparin subc?
PTT unaffected so not monitored
What is the alternative for warfarin in pregnant women?
Heparin - large molecule that doesnt cross
What is the VTE prophy dose for heparin? Where can you administer?
5000-10,000 units subc q8-12hrs
Inject in lower abdomen, inner thighs, or upper arms
What are the 3 G herbs that increase risk of bleeding?
Ginger, garlic, ginkgo biloba
(ginseng decreases INR with warfarin)
When does HIT usually occur with heparin use?
How much would PLTS have to drop from baseline to be considered as thrombocytopenia?
HIT occurs 5-14days usually after initiation of heparin
PLT drop >50% from baseline = thrombocytopenia
How does HIT occur in heparin use? What if it is left untreated?
Immune system forms IgG antibodies against heparin when it binds to platelet factor 4 (PF 4). IgG + heparin + PF 4 forms a complex that binds to platelets, leading to platelet activation and thus a pro-thrombotic state.
If untreated, may lead to venous/arterial thrombosis and amputations, post-thrombotic syndrome, and/or death
For HIT, what is the DOC for pts with renal impairment? Hepatic impairment?
What is the DOC for pts with urgent cardiac surgery or PCI?
Renal impairment = argatroban
Hepatic impairment = lepirudin
Cardiac surgery or PCI = bivalirudin
For HIT pts, when would you initiate warfarin?
When PLT at least 150,000/mm3, overlap with nonheparin anticoagulant for a minimum of 5 days
What is the antidote dose for heparin and LMWH overdose? Max dose?
1mg protamine for 100 units heparin
Max dose 50mg
1mg protamine for 1mg enoxaparin
What is the treatment dose for VTE for heparin?
What type of weight would you use for dosing?
80units/kg IV bolus followed by 18units/kg/hr infusion OR 5000units IV bolus followed by 1000units/hr infusion
Use actual body weight
What are 5 main s/e of heparin? (including 1 long-term s/e)
Osteoporosis (long-term use)
What is the difference b/w type I and type II HIT?
Type 1 is not immune-mediated and occurs within 1st 48h of heparin use and results in mild decrease in PLT.
Type 2 is immune-mediated and occurs 5-14d after heparin use
What are the 3 risk factors associated with HIT in heparin pts?
Heparin for 4 days
What is 1 of the procoagulants that is produced during HIT?
Thrombin (Factor IIa)
What is the most common diagnostic tool for HIT?
Solid-phase enzyme immunoassays (EIA) to detect HIT antibodies
When a pt is diagnosed with HIT, which is the best for pt after d/c heparin?
or transfuse platelets?
Neither. Both may potentiate procoagulant state
What is the duration of tx for HIT with DTI's?
Minimum of 30 days. If thrombosis occurs, tx with anticoagulant for minimum of 6
When would one initiate warfarin in pt resolved with HIT?
After PLT>100,000/mm3, may initiate 5 days before alternate anticoagulant is d/ced
For enoxaparin, what is the DVT prophy dose for hip, knee replacement? For abdominal surgery?
When to initiate?
Hip: 30mg sc q12h 12-24hr post-op or 40mg sc daily 9-15hr pre-op for at least 10 days up to 35 days
knee: 30mg sc q12h. Start 12-24h post-op for 7-10 days, up to 35 days
Abd surgery: 40mg sc daily. Start 2hrs pre-op, for NMT 12 days
Both: CrCL<30: 30mg sc daily
What is DVT/PE tx dose with enoxaparin? Renal dosing?
1mg/kg sc BID, or 1.5mg/kg daily
CrCL<30: 1mg/kg sc daily
What is dosing of enoxaparin for MI, unstable angina, thrombolytic adjunct, and PCI? Renal dosing? Age >75?
1mg/kg sc q12h with ASA
Age>75: 0.75mg/kg sc q12h
CrCL<30: 1mg/kg sc daily
What kind of allergy should one be cognizant about for heparin and LMWH?