Do You Know Your SATs? (Sugar, Acid blockers, Thinners) Laura Habighorst RN CAPA CGRN Heartland SGNA Spring Conference 2014
Objectives Describe the anesthesia contraindications for the administration of metformin. State two examples of patient education regarding the administration of PPIs. Compare and contrast heparin with two of the new anticoagulants.
Metformin: What is it really? 50 year old drug on the market Improves peripheral and liver sensitivity to insulin Reduces liver glucose production Increases insulin-stimulated uptake and utilization of glucose by peripheral tissues
Metformin Uses Type 2 diabetes, especially with overweight patients: Decreases insulin resistance Reduces insulin need Minimizes weight gain May also be used in gestational diabetes; risks remain uncertain Pre-diabetes treatment to prevent Type 2 diabetes
Metformin Uses Non-Alcoholic Fatty Liver Disease: While its etiology is unclear, there is evidence of a pathogenetic role of insulin resistance in the disease. Its effects on weight loss and altering glycemic levels is beneficial in these patients.
Metformin Uses Polycystic Ovary Syndrome: When used in combination with other drugs, may restore regular menstruation and ovulation.
Metformin Uses Cancer: Has been shown to increase survival rates in pancreas, breast, colorectal, lung, and prostate cancer Despite the increase in cancer risk to diabetics, patients on metformin show a reduction in cancer risk by 40%
Metformin So what is the problem? Risk of lactic acidosis: Normal levels 4.5 to 19.8 mg/dl (0.5-2.2 mmol/l) Severe metabolic failure with high mortality HYPOVOLEMIC patients Vitamin B-12 Deficiency
Recommendation to hold metformin 24-78 hours prior to procedures involving: anesthesia Metformin What do we need to do? iodinated contrast dye
Antacids, PPIs, H 2 Blockers Antacids No direct effect on gastric acid secretion Do not protect the gastric mucosa Neutralize gastric acids
Antacids, PPIs, H 2 Blockers Antacids Patient education includes: On an empty stomach effects last one hour For best effect, take one hour after meals and lay down after taking them
Antacids, PPIs, H 2 Blockers Antacids: Cautions Hypermagnesia in patients with chronic renal failure (Maalox, Gaviscon, TUMS) High in sodium, use carefully in patients with CHF, hypertension, or renal failure
Antacids, PPIs, H 2 Blockers PPIs Block production of gastric acid Most popular and effective drugs for GERD: Omeprazole (Prilosec) lansoprazole (Prevacid) Pantoprazole (Protonix) rabeprazole (Aciphex) esomeprazole (Nexium)
Antacids, PPIs, H 2 Blockers PPIs Used also for erosive esophagitis, duodenal ulcers. Can be combined with antibiotics for treatment of H. Pylori
Antacids, PPIs, H 2 Blockers Patient education includes: PPIs Pro-drug - needs to be taken 30 minutes prior to eating Use with caution in patients taking anticoagulants, seizure medications or diazepam r/t drug interactions
Antacids, PPIs, H 2 Blockers H 2 Blockers Reduce the secretion of gastric acid by blocking histamine action in the parietal cells of the stomach. Cimetidine (Tagamet) famotidine (Pepcid) ranitidine (Zantac)
Antacids, PPIs, H 2 Blockers H 2 Blockers May cause diarrhea, headaches, muscle pain Watch blood values for leukopenia and thrombocytopenia
Thinners 3 types of blood thinners: Anticoagulants Vitamin K Antagonist Combination of both
Drug Action Administration Measurement/ Reversal Agent Heparin Anticoagulants Binds to antithrombin which inhibits the coagulation cascade and suppresses the formation of fibrin IV or SQ Weight based with initial bolus then continuous infusion PTT Half-life is 90 minutes Reversal Agent: Protamine Enoxaparin (Lovenox) Dalteparin (Fragmin) Tinzaprin (Innohep) Low molecular weight heparin Interferes with Factor X preventing formation of thrombi SC Anti-factor X assay Half-life is 3-5 hours Reversal Agent: Protamine, FFP
Vitamin K antagonists Drug Action Administration Measurement/ Reversal Agent Warfarin (Coumadin) Dabigatron (Pradaxa) Interfers with Vitamin K metabolism; prevents extgension of existing thrombi and formation of new thrombi Direct thrombin inhibitor or Factor II a inhibitor PO Sliding scale to reach therapuetic levels based upon origional diagnosis PO PT/INR Half-life 6-72 hours depending upon clotting factors Reversal agent: Vitamin K, FFP, prothrombin complex concentrate, reecombinant factor (rviia) No measurement Reversal agent: Protamine
Vitamin K antagonists Drug Action Administration Measurement/ Reversal Agent Fondaparinux (Arixta) Direct thrombin inhibitor PO Does not need bridge No measurement/ reversal Rivaroxaban (Xarelto) Direct Factor Xa inhibitor PO Does not need bridge No measurement/ reversal Half-life 5-13 hours Apixaban (Eliquis) Factor Xa inhibitor PO Does not need bridge No measurement/ reversal Half-life 12 hours
So what about the drugs without measurement tools? May use thrombin time and ecarin clotting times for dabigatran (Pradaxa) May use anti-fxa assay for rivaroxaban (Xarelto) More research needed for this and for antidotes.
Bottom Line Stay informed about new drugs when you see them Understand pharmacodynamics Know if monitoring tools exist Educate yourself for patient teaching
Do You Know Your SAT score? S Savvy and knowledgeable A Aware of indications, mechanism of actions, monitoring options T Teacher for patient and staff education
References Cicero, A. and Tartagni, E. and Ertek, S. Metformin and its clinical use: New insights for an old drug in clinical practice. Archives of Medical Science. November 9, 2012. 8(5): 907-917. McCarron, K. Stop that clot! Anticoagulant medications 101. www.nursingmadeincrediblyeasy.com. September/October 2010. Lippincott, Williams, and Wilkins. Pezotti, W. and Freuler, M. Using anticoagulants to steer clear of clots. Nursing 2012. February 2012. Lippincott, Williams, and Wilkins. Gastroenterology nursing: A core curriculum, 5th edition. Society of Gastroenterology Nurses and Associates. 2013. Wells, M.K. Understanding the new emerging oral anticoagulants for venous thromboembolism prophylaxis. Orthopedic Nursing. September/October 2012. Volume 31, Number 5, pp. 265-278.
Thank you and Have a Sweet Evening!