We continue our NCLEX Drug review series with a new section Drugs that Affect the Blood – Part 1
Anticoagulants (Parenteral)
Expected Action: Intrinsic factors and thrombin conversion are inhibited by heparin
Example: Heparin — Others: enoxaparin, tinzaparin (Innohep)
Therapeutic Uses: Evolving stroke, PE, MI, DVT, during pregnancy, Adjunct during ♥ surgery, dialysis, abdominal surgery, or joint replacement, Disseminated intravascular coagulation
Adverse Effects Hypersensitivity reaction (chills, fever, urticaria), Hemorrhage 2º heparin OD (treat ĉ protamine sulfate), Heparin-induced thrombocytopenia (stop if PLT < 100,000/cc)
Contraindications/Precautions:
CI: Decreased PLT or uncontrollable bleeding
CI: Surgery of eye, brain, spinal cord; regional anesthesia; lumbar puncture
Interactions: Anti-platelet agent leads to additive risk of bleeding
Education: Monitor aPTT levels Q4-6h and then QD (60-80 sec)
Treatment of Heparin OD
Expected Action: Binds with heparin and forms a non-coagulating complex
Drug: Protamine sulfate
Therapeutic Uses: Antidote to severe heparin overdose, Reversal of heparin administered during procedures
Education: Administer slowly (20 mg/min or 50 mg in 10 min), aPTT levels of 60-80 sec
Anticoagulant (Oral)
Expected Action: Antagonizes vitamin K / prevents synthesis of 4 intrinsic factors & prothrombin
Example: warfarin (Coumadin)
Therapeutic Uses: Prevention of venous thrombosis, Prevention of thrombi in A-fib and with prosthetic heart valves
Adverse Effects: Hemorrhage (Tx with vitamin K)
Contraindications/Precautions:
Pregnancy (X)
CI: Surgery of eye, brain, spinal cord; regional anesthesia; lumbar puncture
CI: decreased PLT counts, uncontrolled bleeding, vit. K δ, liver problems, alcoholism
Interactions:
Heparin, aspirin, glucocorticoids leads to increased bleeding
Acetaminophen, sulfonamides, parenteral cephalosporins, ASA leads to ñ [warfarin]
Phenobarbital, carbamazepine, phenytoin, OC, vitamin K leads to decreased warfarin effects
Education:
PT therapeutic level = 18-24 sec (normal = 11-12.5 sec), Onset takes 8-12 hrs, full effect takes 3-5 days
Treatment of Warfarin OD
Expected Action: Promote synthesis of intrinsic factors and prothrombin
Drug name: Vitamin K (Phytonadione)
Therapeutic Uses: Vitamin K deficiency, Reversal of hypoprothrombinemia and bleeding d/t warfarin OD
Adverse Effects: Anaphylactoid reaction (infuse slowly in diluted solution)
Education: Administer small doses (2.5 mg PO / 0.5-1 mg IV) of vitamin K to prevent development of resistance to warfarin.
Antiplatelets
Expected Action Prevent platelet clumping by inhibiting arterial clotting enzymes and factors
Example: Aspirin — Others: ticlopidine (Ticlid), clopidogrel (Plavix), dipyridamole (Persantine), abciximab (Reo Pro)
Therapeutic Uses: Primary prevention of acute MI, Prevention of stroke, Prevention of reinfarction, Acute coronary syndromes (abciximab and tirofiban {Aggrastat})
- Adverse Effects: GI effects (concurrent PPI / enteric-coated / take ĉ food), Hemorrhagic stroke
Contraindications/Precautions: Pregnancy (D)
Interactions:
Medications that enhance bleeding leads to additive risk for bleeding
Education:
ASA (81 mg) for prevention / ASA (325 mg) during initial acute MI episode
Thrombolytic Medications
Expected Action:
Clot dissolution by plasminogen leads to plasmin which destroys fibrinogen
Proto: streptokinase Others: alteplase (tPA), tenecteplase, reteplase
Therapeutic Uses: Acute MI / DVT / Massive PE / Ischemic stroke (alteplase)
Adverse Effects: Serious risk of bleeding from different sites
Streptokinase Hypotension (infuse slowly), Allergic reaction or anaphylaxis
Contraindications/Precautions:
Hx of intracranial hemorrhage, Brain tumors / pericarditis / Recent head or facial trauma / internal bleeding
Interactions: Meds that enhance bleeding have additive risk for bleeding,
Education: Admin within 4-6 hours of onset, IV aminocaproic acid for excessive fibrinolysis, Administer H2 antagonists such as ranitidine (Zantec) or PPI such as omeprazole (Prilosec) to prevent GI bleeding.
Iron Preparations
Expected Action: Increase iron level for RBC development and oxygen transport capacity
Example: Ferrous sulfate — Others: Iron Dextran
Therapeutic Uses: Treat and prevent iron-deficiency anemia
Adverse Effects: Teeth staining (liquid) {Dilute / Drink ĉ straw / Rinse}, GI distress: {take ĉ food if necessary but greatly decreases absorption}, Anaphylaxis (parenteral): IV is safer / Deep IM ĉ Z-track / Infuse slowly
Interactions:
Vitamin C leads to increased absorption but increases side effects
Antacids or tetracyclines leads to decreased absorption
Education: Take on empty stomach to ñ absorption, Anticipate dark green or black stool
Vitamin B12 – (Cyanocobalamin)
Expected Action: Necessary to convert folate (required for DNA production) from inactive form
Therapeutic Uses: Treatment of B12 deficiency, Megaloblastic (macrocytic) anemia related to B12 deficiency
Adverse Effects: Hypokalemia 2º increased RBC production
Interactions: Folic acid supplements mask signs of B12 deficiency
Education: Intranasal spray / oral / IM / SC, Injections are painful; reserved for reduced ability to absorb.
Folic Acid
Expected Action: Folic acid is essential in DNA production & erythropoiesis (RBC, WBC, PLT)
Therapeutic Uses: Tx of macrocytic anemia, Prevention of neural tube defects in pregnancy
Interactions: Sulfonamides, sulfasalazine, methotrexate leads to decreased folate levels ĉ concurrent use
Past Medication posts –
Nervous System Meds (4 parts)
http://www.nclexreviewonline.com/nervous-system-medication-part-1-the-receptors/
http://www.nclexreviewonline.com/nervous-system-meds-drugs-part-2/
http://www.nclexreviewonline.com/medications-affecting-the-nervous-system-part-3/
Cardiac Medications
Part 1 – http://www.nclexreviewonline.com/cardiac-drugs-for-nclex-part-1/
Part 2 – http://www.nclexreviewonline.com/nclex-cardiac-drugs-part-2/
Part 3- http://www.nclexreviewonline.com/nclex-cardiac-drugs-part-3/
Pain Meds and Inflammation – http://www.nclexreviewonline.com/nclex-test-help-pain-meds-and-inflammation/
Immunity and Chemo – http://www.nclexreviewonline.com/nclex-drugs-immunity-and-chemotherapy/
Anti Infective Drugs – http://www.nclexreviewonline.com/anti-infective-drugs-part-1/
More information can be found on our blog – http://www.nclexreviewonline.com/the-blog/
