Pharmacology Quiz. Week 1-3

Chapter 1: The Role of the Advanced Practice Nurse as Prescriber Advanced Practice Registered Nurses: 21 states allow full independent prescribing. I. Roles and Responsibilities of APRN Prescribers a. All states have ...

Chapter 1: The Role of the Advanced Practice Nurse as Prescriber Advanced Practice Registered Nurses: 21 states allow full independent prescribing. I. Roles and Responsibilities of APRN Prescribers a. All states have title protection for NPs. b. Only Oregon has mandated third-party reimbursement parity for NP services. c. In all but five states, the control of practice and licensure is within the sole authority of the state’s board of nursing. These five states have joint control in the board of nursing and the board of medicine. d. Scope of practice is determined by the individual NP’s license under the nurse practice act of the licensing jurisdiction. Some have a graduated scope based on experience level. New prescribers need to understand that their employment sites may restrict this legal scope of practice but cannot extend it. e. In 17 states and the District of Columbia, NPs have independent scope of practice and prescriptive authority without a requirement or attestation for physician collaboration, consultation, delegation, or supervision. f. Six states have full autonomous practice and prescriptive authority following a period of post-licensure/post-certification supervision or collaboration. Nurse practitioner prescriptive authority is regulated by: 1. The National Council of State Boards of Nursing 2. The U.S. Drug Enforcement Administration 3. The State Board of Nursing for each state 4. The State Board of Pharmacy II. III. Advanced Knowledge a. As a prescriber, it becomes the role and responsibility of the NP to determine the diagnosis for which the drug will be ordered, prescribe the appropriate drug, monitor the expected outcome of the drug, and incorporate a holistic assessment of the impact of disease and therapy on patient lives. b. APRN needs to be aware of the new medications on the market. Alerts are sent out via the Med-Watch Safety Alert system as new information becomes available IV. Benefits of an APRN as Prescriber a. Characteristics of APRNs and their practice are consideration of the whole patient, the joint setting of therapeutic goals with the other members of the healthcare team. The benefits to the patient of having an Advanced Practice Registered Nurse (APRN) prescriber include: 1. Nurses know more about Pharmacology than other prescribers because they take it both in their basic nursing program and in their APRN program. 2. Nurses care for the patient from a holistic approach and include the patient in decision making regarding their care. 3. APRNs are less likely to prescribe narcotics and other controlled substances. 4. APRNs are able to prescribe independently in all states, whereas a physician’s 1 assistant needs to have a physician supervising their practice. V. Clinical Judgment in Prescribing a. Is there a clear indication for drug therapy? i. Increased awareness of the limitations of drugs i.e. antibiotic resistance b. What drugs are effective in treating this disorder? i. Nationally recognized guidelines including NIH, Agency for Health Care Quality help by publishing disease-specific treatment guidelines. c. What is the goal of therapy with this drug? i. Short-term cure or long-term management? d. Under what conditions is it determined that a drug is not meeting the goal and a different therapy or drug should be tried? e. Are there unnecessary duplications with other drugs that the patient is already taking? f. Would an OTC drug be just as useful as a prescription drug? i. This can be helpful or hurtful to patients, as insurance will stop covering OTC medications. g. What about cost? i. Newer the drug the higher the cost. Awareness is key because of factors likely to lead to poor adherence related to finances. h. Where is the information to answer these questions? i. Micromedex, Lexicomp, Epocrates, and the FDA Criteria for choosing an effective drug for a disorder include: 1. Asking the patient what drug they think would work best for them 2. Consulting nationally recognized guidelines for disease management 3. Prescribing medications that are available as samples before writing a prescription 4. Following U.S. Drug Enforcement Administration guidelines for prescribing VI. Collaboration with other Providers a. Physicians: initially MDs were the teachers of NPs. i. Physicians look at pharmacology based on understanding biochemistry and prescribing for a given pathophysiology. The emphasis is on the disease and the drug, with less on the impact on the patient. They are weak in patient education ii. NPs approach for prescribing places an equal emphasis on understanding the impact the drug will have on the patient. Strong patient education teaching skills. b. Pharmacists: must have a doctorate. Extensive knowledge about patho and take an active role in determining the best drug to prescribe. c. Other APRNs: share “clinical pearls” from their knowledge base d. Physician Assistants: not autonomous. Similar hierarchy as NPs e. Nurses not in Advance Practice Roles 2 i. Diabetic educators, wound care nurses VII. Canadian Nurse Practitioner Practice a. Similar to US. Determined by province VIII. Current Issues and Trends in Health Care and Their Effect on Prescriptive Authority a. Autonomy and Prescriptive Authority: we have overcome the cannot prescribe, diagnose and admit but turf wars remain. b. Interdisciplinary Teams: lets all play nice in the sand box c. Level of Education of Team Members: we should all become DNPs d. Reimbursement: we should all get paid the same, pay is a practice barrier. Nurse practitioner practice may thrive under health-care reform because of: 1. The demonstrated ability of nurse practitioners to control costs and improve patient outcomes 2. The fact that nurse practitioners will be able to practice independently 3. The fact that nurse practitioners will have full reimbursement under health-care reform 4. The ability to shift accountability for Medicaid to the state level Chapter 2: Review of Basic Principles of Pharmacology I. Pharmacology – The Study of Drugs a. Drug: any chemical substance that produces a measurable biological response. II. How New Drugs are Developed a. Preclinical: testing medications in cells, isolated tissues and organs, and lab animals. b. Clinical: working with the FDA must prove that the drug is safe and effective. Starts out with a small healthy cohort, then on actually targeted patients and then spread out cohorts. III. Drug Responses: drugs must overcome homeostasis to be effective. a. Dose-Response Curves: the higher the concentration of a drug at its site of action, the more the drug will bind to the receptor and the greater will be the response. b. Two Types of Drug Responses: i. Quantal: Responses that may or may not occur. If we measure as either occurring or absent it is quantal. 1. Ex. Sleep, rash, seizures, pregnancy, and death. ii. Graded: biological effects that can be measured continually up to the maximum responding capacity of the biological system. Easier to manage clinically because we can see the effects and then adjust the dose. 1. Ex. BP, HR, diuresis, bronchodilation, FEV1, Pain and coma scale iii. They are not mutually exclusive. I.e. Adjusting seizure medications to have fewer occurrences (graded), even though the goal is to be seizure free (quantal). c. Expressing Drug Responses 3 i. Dose response curves provide information on the relationship between dosage or concentration and responses for one or more drugs. ii. Drugs are compared using potency, efficacy, intrinsic activity and selectivity. 1. Potency, how much drug is needed to produce a biological response. 2. Efficacy, ability of the drug to produce a maximum effect at any dosage. 3. Intrinsic activity is similar to efficacy; however it is used to describe the ability of a drug to produce a response once it has occupied specific receptors. d. Drug Selectivity: a ratio of the dose or concentration producing the undesired effect to the dose or concentration producing the desired effect. i. Therapeutic index is a special ratio describing drug selectivity versus the lethal dose. e. Drug Responses in the Real World, using the placebo effect to create a baseline for measurement of the dose-effect curve. f. Brand versus Generic Drugs: After the original drug patent expires other companies can manufacture generic drugs using the same amount of active ingredient as the brand. IV. Receptors: large protein molecules that interact with and mediate the action of drugs. They determine the relationship between dose and effect, the selectivity of drugs, and the actions pharmacological antagonists. a. Ion Channel Receptors: transmits signals across the cell membrane by increasing the flow of ions and altering the electrical potential. i. Responses have rapid onset and short duration. b. Receptors Coupled to G Proteins: c. Transmembrane Receptors: extracellular hormone-binding domain and an intracellular enzyme domain that phosphorylates the amino acid tyrosine. d. Intracellular Receptors Regulating Gene Expression: e. Enzymes f. Drug Action at Receptors: i. Agonists: drugs that produce receptor stimulation and conformational change every time they bind. Overtime they can downregulate the numbers of that specific receptor and become desensitized. ii. Antagonists: drugs that occupy receptors without stimulating them. They prevent other molecules, such as agonists, from producing a response. 1. Beta-blockers, if abruptly discontinued can cause an exaggerated response. g. Disease States and Receptors h. Non-receptor Mechanisms V. Pharmacokinetics a. Absorption 4 i. Parental Administration: injection, given when immediate effect is required, ingredients are destroyed or not absorbed in the GI tract, or when patient is unable to take oral medication. 1. IV is the fastest route and is the standard for which other routes are compared too. ii. Oral: most common and convenient. Slower, requiring time to open or dissolve to enter systemic circulation. Liver is the location of drug metabolism before reaching the bloodstream. iii. Sites of Administration: Higher concentrations are achieved when meds are given closest to the desired target. iv. Bioavailability: not all meds are dissolved or absorbed or survive liver passage, only a fraction makes it to the bloodstream. Range from 10-90% 1. Important for drugs with narrow therapeutic ranges or sustainedrelease mechanisms v. Peak Blood Levels: the speed at which drugs enter the bloodstream, faster the speed the increase in toxicity and adverse effect. Phenytoin for example needs peak and trough levels drawn to determine if the drug is in the therapeutic range. 1. Steady state is when the amount of drug in the body remains constant, usually occurs after 4 to 5 half-lives. b. Distribution: process of drugs moving throughout the body. i. Properties that affect distribution 1. Henderson-Hasselbalch Relationship, protein binding, transport systems, and volume of distribution 2. Albumin is critical to the distribution of drugs to target tissues 3. The blood-brain barrier lows the entry of many drugs into and from the brain cells. c. Metabolism: process of changing one chemical into another, and either creates or uses energy. Liver is the main center for drug metabolism because it is the first organ encountered by drugs from the GI tract and contains high amounts of drugmetabolizing enzymes. “First-pass metabolism” i. Drugs that have a significant first-pass effect are rapidly metabolized by the liver and may have little if any desired action. ii. Phase 1 and phase 2 reactions change drug molecules to a form that an excretory organ can excrete. iii. Metabolism and Half-life: drugs should be administered at dosing intervals that are close to their half-life. Half-life is the time required for the amount of drug in the body to decrease by 50%. d. Drug Interactions: alterations in biotransformation are responsible for many interactions. e. Excretion: principal organs of excretion are kidneys, lungs, biliary system, and intestines. 5 i. Renal: primary organ for most drugs that create metabolites that are watersoluble. ii. Renal excretion of drugs: the rate is dependent on renal blood flow, molecular drug size, the charge, the degree of protein binding, and tubular acidity. iii. Biliary excretion: drugs can enter bile and then be excreted into the intestinal tract when bile is released. iv. Other sites: 1. Pulmonary (lungs): occurs for any volatile material present in the body. Important for anesthetic gases and alcohol