NUR 635 Advanced Pharmacology Mid-Term Exam (Correctly answered with Rationales)

The process by which the body break down and coverts a medication into active subtance is know as metabolism The term NOT associated with the pharmacokinetics of a drug is Pharmacodynamics R ationale: Pharmacokinetics can be simply described as the study of 'what the body does to the drugs' and includes: the rate and extend to which drugs are absorbed and distributed to body tissue; the rate and pathways by which drugs are eliminated from the body by metabolism and excretion; and the relationship between time and plasma drug concentration. It includes the processes of absorption, distribution, metabolism, and excretion. Pharmacodynamics is the effect that a drug has on the body. Terms associated with pharmacodynamics include receptors (i.e. affinity), drug potency (i.e. amount of drug required to produce a therapeutic response), and drug response cure (i.e. effective dose, toxic dose, therapeutic index). The elimination phase of pharmacokinetics is the time it takes for the plasma concentration of a drug to decrease by 50% Rationale: The elimination phase or elimination half-life is the time required for a drug to reach half (50%) of its state in the serum. The pharmacokinetics of a drug may be affected by Compliance by the patient. Rationale: Factors that affect the pharmacokinetics (what the body does to the drug) of a drug include: compliance by the patient; dosing and medication error; absorption; tissue and body fluid; mass and volume; drug interaction; elimination and drug metabolism. Pharmacokinetics will be variable if the drug does not reach the body or doesn't stay in the body long enough. Pharmacodynamics (what the drug does to the body) is affected by drug receptors, genetic factors, drug interaction, and tolerance. In the pharmacokinetics of a drug, the rate of metabolism: varies widely among patients. Rationale: Metabolism is the process by which drugs are chemically changed from a lipid-soluble from suitable for absorption and distribution to a more water-soluble form that is suitable for excretion. The rate of drug metabolism varies widely among patients, influenced by genetic and environmental factors. This is the major reason for differences in the plasma concentration of some drugs after a standard dose, leading to wide variation in drug response. The type of study that defines the mayor metabolites concentrations in serum and other body compartment is: Pharmacokinetics Studies Rationale: Pharmacokinetics studies are intended to define the time course of a drug's effect and the major metabolite concentration in the serum and other body compartment. Pharmacokinetics is: the effect the body has on the drug Rationale: Pharmacokinetics is the branch of pharmacology concerned withe characteristic interactions of a drug and the body in terms of its absorption, distribution, metabolism, and excretion.Simply put , it is what the body does to the drug. Pharmacokinetics includes the study of: the rate and extent to which drugs are absorbed into the body and distributed to the body tissue; the rate and pathways by which drugs are eliminated from the body by metabolism and excretion; the relationship between time and plasma drug concentration. Isosorbide dinitrate (Isordil) is indicated for the treatment of: Chronic Angina Rationale: Isosorbide dinitrate (Isordil) titradose tablets are indicated for the prevention of angina pectoris due to coronary artery disease. The onset of action of immediate-release oral isosorbide dinitrate is not sufficiently rapid for this product to be useful in aborting an acute angina episode. Therefore, it is not indicated int the treatment of acute angina and myocardial infarction. What is the maximum half-life elimination of warfarin (Coumadin)? 60 hours Rationale: The half-life elimination of warfarin (Coumadin) is 20-60 hours. The onset of anti coagulation action for oral warfarin (Coumadin) is 24-72 hours. Warfarin acts by binding the synthesis of vitamin K-dependent clotting factors, including Factor II, VII, IX, and the anticoagulant proteins C and S. A 2 year old child has history of heart failure. To increase the force of ventricular contraction and decrease heart rate, the most appropriate drug choice is: a. captopril [Capoten] b. enalapril [Vasotec] c. digoxin [Lanoxin] d. diltiazem [Cardizem] c. digoxin [Lanoxin] Rationale: Digoxin has a rapid onset. It increases the force of contraction, decreases heart rate, slows the conduction of impulses through the AV node, and indirectly enhances diuresis. When dosed appropriately, it is effective and indicated in pediatric patients. Captopril and enalapril do not decrease heart rate. Diltiazem decreases heart rate and decreases of contraction. Non-dihydropyridine CCBs (i.e. verapamil) may be safely used in patients with: a. heart failure with reduced ejection fraction b. chronic stable angina c. second or third degree AV block d. sick sinus syndrome b. chronic stable angina Rationale: Non-Dihydropyridine CCBs verapamil [Calan] and diltiazem [Cardizem] have negative chronotopic and inotropic effects. Therefore, they slow down heart rate and decrease force of ventricular contractions. Non-DHP CCB's are contraindicated in patients with heart failure who have reduced ejection fraction, sick sinus syndrome, and second or third degree AV block. Since non-DHP CCB's increase myocaridal blood flow by dilating coronary arteries, they are beneficial in patients with chronic stable angina. Additionally, they can be given for rate control (tachycardia) or for the control of angina (chronic stable) when left ventricular systolic function is normal. Warfarin (Coumadin) therapy may be safely used by patients who has: a. moderate renal impairment b. active tuberculosis c. chronic obstructive pulmonary disease d. malnutrition c. chronic obstructive pulmonary disease Rationale: Warfarin (Coumadin) is not contraindicated in patients with chronic obstructive pulmonary disease. In patients with moderate renal impairment, active tuberculosis and malnutrition, warfarin should be used with caution or avoided. Beta-blockers such as atenolol (Tenormin) should not be used in patients with: a. post MI prevention b. heart failure c. stable angina d. variant (Prinzmetal) angina d. variant (Prinzmetal) angina Rationale: Beta-blockers should not be used in patients with vasospastic or variant (Prinzmetal) angina. In such patients, they are ineffective and may increase the tendency to induce coronary vasospasm from unopposed alpha-receptor activity. Beta-blockers are indicated in the treatment of post-MI prevention, heart failure and stable angina. Apixaban (Eliquis) may be a better choice than warfarin (Coumadin) in the patient who: a. is pregnant b. has heparin-induced thrombocytopenia c. has renal impairment d. cant afford the warfarin b. has heparin-induced thrombocytopenia Rationale: Warfarin (Coumadin) is contraindicated in the treatment of heparin-induced thrombocytopenia. Factor Xa inhibitors, such as apixaban (Eliquis), should NOT be used in patients who are pregnant. Drugs in this class are expensive. They are excreted renally and should be avoided in patients who have renal impairment. Statins lower cholesterol by: competitively inhibiting HMG-CoA reductase. competitively inhibiting HMG-CoA reductase. Nifedipine (Adalat CC), a calcium channel blocker, is indicated in the treatment of: a. chronic stable angina b. ST-elevation myocardial infarction c. cardiovascular shock d. heart failure a. chronic stable angina Rationale: Nifedipine (CCB) is indicated for the treatment of chronic stable or vasoactive angina and hypertension. Nefedipine is a dihydropyridine. The most smooth muscle-selective class of CCB is the dihydropyridines. Adalat is contraindicated in the other options. Lipid-lowering agents that has been proven most effective in raising high-density lipoprotein levels is: a. nicotinic acid b. statin class c. bile acid sequestrants d. fibric acids a. nicotinic acid Rationale: nicotinic acid (Niacin) has the highest potential for raising high-density lipoproteins (HDL) (15-30%). Unfortunately, no improvement in cardiovascular outcomes has been documented when niacin is used with or without statin. Consequently, the FDA has removed this as an indication on the product label. Other lipid-lowering agents may raise HDL at rates of: statins 5-15%, bile acid sequestrants 3-5%, and fibric acids 10-20%. Patients taking warfarin (Coumadin) therapy should: a. eliminate vitamin K from diet b. reduce vitamin K enriched foods c. increase vitamin K enriched foods d. maintain a consistent intake of vitamin K enriched foods. d. maintain a consistent intake of vitamin K-enriched foods. Rationale: Patients who are anticoagulated with warfarin generally are sensitive to fluctuations in vitamin K intake. Adequate INR control requires a consistent intake of vitamin K. The goal of monitoring vitamin K intake is to maintain a moderate, const