NRNP 6566 WK1-5 Midterm Exam with complete solutions

Describe cytochrome p450 system - ANSWER Cytochrome p450 system is a series of enzymes used to metabolize medications Inhibitors - ANSWER block metabolic activity from one or more CYP450 enzymes Inducers - ANSWER increase CYP450 enzyme activity by increasing enzyme synthesis Describe effect on low and high albumin levels on active drug levels especially for drugs that are highly protein bound - ANSWER Albumin is the plasma protein with the greatest capacity for binding drugs. Binding plasma proteins affect drug distribution into tissues, because only drug that is not bound is available to penetrate tissues, bind to receptors, and exert activity. As free drug leaves the blood stream, more bound drug is released from binding sites. Low albumin levels - ANSWER malnutrition, chronic illness Highly protein bound drugs can lead to - ANSWER toxicity in patients with low albumin levels, example malnutrition or chronic illness. This is because there are fewer than the normal sites for the drug to bind Describe the ways the hepatic first pass effect- which is metabolism during first pass through the liver - ANSWER Alternative routes include: suppository intravenous intramuscular inhalational aerosol transdermal sublingual These allow drugs to bypass the first-pass effect and be absorbed directly into systemic circulation Be able to calculate creatinine clearance using Cockgraft Gault equation: - ANSWER Male = 140-age times weight in kilograms divided by serum creatinine times 72. Women = CRCL (male) times 0.85 Describe what determines the frequency of drug administration - ANSWER half life plasma concentration Be familiar with the beers criteria and how to use it - ANSWER Potentially Inappropriate Medication Use in Older Adults to call attention to medications that are most commonly problematic and thus should be avoided in older adults Describe factors that affect absorption - ANSWER low blood state (shock or arrest), contact time with GI tract too fast (diarrhea = cant absorb), delayed stomach emptying (large meal = delayed absorption)Drug- to drug or drug to food interactions Describe the factors that affect distribution - ANSWER low albumin levels, body composition, cardiac decompensation (heart failure), age Describe the factors that affect metabolism - ANSWER genetics, age, organ function Describe factors that affect excretion - ANSWER affected by abnormal kidney or liver function, age, drug interactions Define narrow therapeutic index. How would you monitor a patient with a narrow therapeutic index? - ANSWER Therapeutic index is the dose range of effiency of med is optimized while side effects are minimized Narrow therapeutic index drugs are defined as those drugs where small differences in dose or blood concentration may lead to dose and blood concentration dependant, serious therapeutic failures or adverse drug reactions. You will need to monitor blood tests to monitor blood concentrations and dose adjustments accordingly. Describe how aging can affect absorption, distribution, metabolism and excretion - ANSWER decreased organ function, poorly tolerate drugs that require metabolism, lower rates of excretion decrease in small-bowel surface area, slowed gastric emptying, increase in gastric PH, changes in drug absorption With age, body fat generally increases and total body water decreases. Increased fat increases the volume of distribution for highly lipophilic drugs (for example, diazepam and chlordiazepoxide), which may increase their elimination half-lives. Serum albumin decreases and alpha 1 acid glycoprotein increases -- Phenytoin and warfarin are examples of medications with a higher risk of toxic effects when serum albumin increases hepatic metabolism of many drugs through cytochrome P enzyme system decreases with age; decreasing 30-40% decreased renal elimination Identify 1st degree heart block - ANSWER cardiologist consult Order echo to rule out structural diagnosis, check thyroid levels, medications, electrolytes and identify and treat cause Identify 2nd degree heart block - ANSWER permanent pacemaker, continuous tele monitoring, possible transcutaneous pacing, determine cause; IV atropine if poor perfusion s/s every 3-5 minutes with max of 3mg if poor perfusion. No response to atropine, use dopamine, epinephrine, isoproterenol Identify 3rd degree heart block/complete heart block - ANSWER Permanent pacemaker, telemetry monitoring and transcutaneous pacing if needed, identify cause, IV atropine if s/s poor perfusion. If no response to atropine, use dopamine, epinephrine and isoproterenol Atrial fibrillation - ANSWER Stable- rate control versus rhythm control strategy (example: AV nodal blockers, antiarrhythmics, anticoagulation). Ablation may be needed if no response to medications Unstable- DCC/ cardioversion Atrial Flutter - ANSWER Cardioversion Rate control not as responsive as Afib Ventricular fibrillation - ANSWER Defibrillate and CPR Ventricular Tachycardia - ANSWER Stable- betablocker Amiodarone, sotalol, mexiletine to reduce number of shocks MG if torsades EPS / ablation Unstable - CPR, epinephrine vasopressin, amiodarone, lidocaine, magnesium, airway management Tachycardia - ANSWER vagal manuever, adenosine (6 or 12 mg), betablocker or calcium channel blocker. Know what conditions each class would be used to treat Dihydropyridine Calcium Channel Blockers - ANSWER nefedipine, amlodipine these primarily act on vascular smooth muscles Use this for hypertension Non-Dihydropyridine Calcium Channel blocker - ANSWER Diltiazem verapamil Primarily act on the heart Use these for CP, SVT (verapamil), controlling irregular heart rate and lowering blood pressure (Diltiazem) CHADS 2 score - ANSWER anything greater than 3 is high risk and start anticoagulant 1 point for each with history of heart failure, hypertension, and diabetes mellitus Stroke is 2 points and greater than 75 years old is one point Hyperthyroidism - ANSWER heat intolerance fatigue anxiety nervousness manic confusion / restless emotional liability fine tremors diaphoresis hyperreflexia of deep tendon reflexes resting tachycardia, palpitations, afib exterional dyspnea low-grade fever increased appetite weight loss fine thin hair exopthalamus Graves Abnormal labs with hyperthyroidism - ANSWER elevated T3, T4, thyroid resin uptake, and free thyroxine index. Sometimes T4 is normal but T3 is always high Elevated sed rate Elevated antinuclear antibody, without evidence of lupus or autoimmune disorder Hypercalcemia and low h/h Treatment for hyperthyroidism - ANSWER propanolol (inderal) 10mg 4 times a day (up to 80 mg) Metoprolol 25 mg by mouth (Up to 50 mg) every 6*8 hours Antithyroid medications- methimazole (tapazole) initial dose is 30 to 60mg a day in three doses, and then maintenance of 5 to 15 mg daily If intolerant to tapazole, propylthiouracil initial dose is 300 to 600 mg a day in 4 doses, maintenance dosage is 100 to 150 mg daily in three doses Identify when cardioversion is indicated and relevant testing that should occur prior to it - ANSWER Unstable afib / flutter causing RVR, MI, hypotension or heart failure; WPW syndrome in a fib TEE should always proceed DCCV to rule out valve disease or thrombus Hypertension definition - ANSWER sustained BP of 140's over 90's for a sustained period of time Stage 1 is 140-159; and 90-99 diastolic Stage 2 is equal or greater than 160 over greater or equal to 100 diastolic Essential hypertension - ANSWER unknown cause 95% cases; onset 25 years old - 55 Secondary hypertension- related to known cause or disease process. This could be from estrogen uses, renal disease, pregnant, endocrine disorders Isolated systolic blood pressure- hypertension and systolic blood pressure greater than 140 over 90 Effectively treated with diuretics and long-acting calcium channel blockers Signs and symptoms of hypertension: headache in the morning, epitaxis, lightheadedness, visual disturbances, S4 present related to left ventricular hypertrophy, retinal changes, hematuria (which is rare) Hypertensive urgency - ANSWER severely elevated blood pressure 180 over 110 or higher without progressive target organ dysfunction signs and symptoms: severe headache, shortness of breath, epistaxis, severe anxiety treatment includes Clonidine (alpha-adrenergic stimulant 0.2 mg initial dose, then 0.1 mg every hour until controlled or total of 0.8 mg May experience sedation, possible rebound hypertension once stopped Captopril - ACE dose of 12.5 to 25mg Hypertensive emergency - ANSWER Severely elevated blood pressure 180 over 120 can occur with lower blood pressure if impending or progressive target organ dysfunction ( example : encephalopathy, intracranial hemorrhage, acute myocardial infarction, pulmonary edema with acute LV failure, unstable angina, dissecting aortic aneurysm or eclampsia First intervention - goal is to get blood pressure down to 160-180 or less than 105 diastolic. First drug choice is nicardipine 2.5 to 1.5 mg hour intravenously. Side effects include headache, hypotension, tachycardia, nausea/vomiting, fever, neck pain, indigestion Second medication is nipride 0.25 to 10 micrograms per kilogram per minute intravenously. Side effects include brady or tachycardia, nausea, abdominal pain, twitching, dizziness, headache, flushing, sweating, IV site irritation. This medication can cause rapid profound hypotension. Do not give this medication longer than 72 hours as there is a risk for cyanide poisoning. Nitroglycerin- 5 to 220 micrograms a minute intravenously. Side effects include dizziness, headache, hypotension, orthostatics, numbness/tingling, flushing, nausea/vomiting Other medications: Esmolol hydrochloride Lebetalol - commonly used with pregnant patients Apresoline- do not give to patients with Coronary artery disease and aortic dissection. this is a vasodilator, which decreases blood pressure but increases heart rate and retains fluid Minoxidil is another vasodilator. good for end stage renal patients Fenolodopam Hypertension medications based on history - ANSWER Non-African Americans can take thiazide diuretics, calcium channel blockers, ace inhibitors, ARBs (grade B) African Americans need thiazides, calcium channel blockers (grade b); grade c for patient with diabetes mellitus Adults equal to or greater than the age of 18 with chronic kidney disease- ace inhibitors, ARBS grade b - regardless of race or other comorbidities