Pharmacology Exam Study Guide PDF

PHARMACOLOGY EXAM#2 STUDY GUIDE Pharmacokinetics: is the term that describes the four stages of absorption, distribution, metabolism, and excretion of drugs. Drugs are medications or other substances that have a physiological effect when introduced to the body. Four basic stages for...

PHARMACOLOGY EXAM#2 STUDY GUIDE Pharmacokinetics: is the term that describes the four stages of absorption, distribution, metabolism, and excretion of drugs. Drugs are medications or other substances that have a physiological effect when introduced to the body. Four basic stages for a medication to go through within the human body: Absorption occurs after medications enter the body and travel from the site of administration into the body’s circulation. Distribution is the process by which medication is distributed throughout the body. Metabolism is the breakdown of a drug molecule. Excretion is the process by which the body eliminates waste. Each of these stages is described separately later in this chapter. Pharmacodynamics refers to the effects of drugs in the body and the mechanism of their action. As a drug travels through the bloodstream, it will exhibit a unique affinity for the drug-receptor site, meaning how strongly it will bind to the site. 1.3 Absorption Common routes to administer medications include the following examples: oral (swallowing an aspirin tablet) enteral (administering to the GI tract such as via a NG tube) rectal (administering an acetaminophen [Tylenol] suppository) inhalation (breathing in medication from an inhaler) intramuscular (getting a flu shot in the deltoid muscle) subcutaneous (injecting insulin into the fat tissue beneath the skin) transdermal (wearing a nicotine patch) First Pass Effect Absorption Lifespan Considerations 1.4 DISTRIBUTION Blood Flow Many factors can affect the blood flow and delivery of medication, such as decreased flow (due to dehydration), blocked vessels (due to atherosclerosis), constricted vessels (due to uncontrolled hypertension), or weakened pumping by the heart muscle (due to heart failure). Protein-Binding A common factor impacting distribution of medication is plasma protein in the blood. Albumin is one of the most important proteins in the blood. Albumin levels can be decreased by several factors such as malnutrition and liver disease. A patient taking several highly protein-bound medications often experiences greater side effects. Blood-Brain Barrier Only certain medications made of lipids (fats) or have a “carrier” can get through the blood-brain barrier. Placental Barrier It is imperative to always consult a healthcare provider regarding the safety of medications for use during pregnancy. Distribution Lifespan Considerations 1.5 METABOLISM Metabolism The breakdown of a drug molecule usually involves two steps that take place primarily in the body’s chemical processing plant: the liver. The first step in metabolizing occurs through a process known as the first pass effect, in which orally administered drugs are broken down in the liver and intestines. Metabolism Lifespan Considerations 1.6 EXCRETION Excretion Final stage of a medication interaction within the body. The body has absorbed, distributed, and metabolized the medication molecules. Remaining parent drugs and metabolites in the bloodstream are often filtered by the kidney, where a portion undergoes reabsorption back into the bloodstream, and the remainder is excreted in the urine.. The liver also excretes byproducts and waste into the bile. Another potential route of excretion is the lungs. 1.7 PHARMACODYNAMICS Pharmacodynamics Drug’s impact on the body, a series of complex interactions Important to remember that the majority of drugs bind to specific receptors on the surface or interior of cells Agonist and Antagonist Actions Understanding the mechanism of action, or how a medication functions within the body, is essential to understanding the processes medications go through to produce the desired effect A drug agonist binds tightly to a receptor to produce a desired effect. A drug antagonist competes with other molecules and blocks a specific action or response at a receptor site.  1.8 MEDICATION TYPES Prescription Medications Generic Medications Over-the-Counter Medications Herbals & Supplements 1.9 EXAMINING EFFECT Onset, Peak, and Duration Dosing considerations play an important role in understanding the effect that a medication may have on a patient. Onset: the onset of medication refers to when the medication first begins to take effect Peak: the peak of medication refers to the maximum concentration of medication in the body, and the patient shows evidence of greatest therapeutic effect Duration: the duration of medication refers to the length of time the medication produces its desired therapeutic effect 1.10 MEDICATION SAFETY Therapeutic Window Between these doses is the therapeutic window, where the safest and most effective treatment will occur Peak and Trough Levels A peak drug level is drawn at the time when the medication is being administered and is known to be at the highest level in the bloodstream. A trough level is drawn when the drug is at its lowest in the bloodstream right before the next dose is given. Therapeutic Index Therapeutic Index is a quantitative measurement of the relative safety of a drug. It is a comparison of the amount of drug that produces a therapeutic effect versus the amount of drug that produces a toxic effect. 1.11 PREPARING FOR ADMINISTRATION Monitoring the Effects Potency refers to the amount of the drug required to produce the desired effect. Selectivity of a drug refers to how readily the drug targets specific cells to produce an intended therapeutic effect. A side effect occurs when the drug produces effects other than the intended effect. A side effect, although often undesirable, is generally anticipated by the provider and is a known unintended consequence of the medication therapy. adverse effects. Adverse effects are relatively unpredictable, severe, and are reason to discontinue the medication. 2.3 LEGAL FOUNDATIONS AND NATIONAL GUIDELINES FOR SAFE MEDICATION ADMINISTRATION Black Box Warnings Black Box Warnings are issued by the FDA and appear on a prescription drug’s label. The purpose is to call attention to serious or life-threatening risks. Figure 2.2 Definitions and Sample Medications for Each Type of Scheduled Medication Schedule Definition Examples No currently accepted medical use Schedule I Heroin, LSD, and marijuana and a high potential for abuse. High potential for abuse, with use Vicodin, cocaine, methamphetamine, potentially leading to severe methadone, hydromorphone Schedule II psychological or physical (Dilaudid), meperidine (Demerol), dependence. These drugs are also oxycodone (OxyContin), fentanyl, considered dangerous. Dexedrine, Adderall, and Ritalin Moderate to low potential for physical and psychological dependence. Abuse potential is Tylenol with codeine, ketamine, Schedule III less than Schedule I and Schedule anabolic steroids, testosterone II drugs but more than Schedule IV. Low potential for abuse and low Xanax, Soma, Valium, Ativan, Schedule IV risk of dependence. Talwin, Ambien, Tramadol Lower potential for abuse than Schedule IV and consist of preparations containing limited Robitussin AC with codeine, Lomotil, Schedule V quantities of certain narcotics. Lyrica Generally used for antidiarrheal, antitussive, and analgesic purposes. Improving Medication Safety: Actions for Nurses Establish safe work environments for medication preparation, administration, and documentation; for instance, reduce distractions and provide appropriate lighting. Maintain a culture of rigorous commitment to principles of safety in medication administration (for instance, the five rights of medication safety and cross-checks with colleagues, where appropriate).  Remove barriers and facilitate the involvement of patient surrogates in checking the administration and monitoring the medication effects. Foster a commitment to patients’ rights as co-consumers of their care. Develop aids for patients or their surrogates to support self-management of medications. Enhance communication skills and team training to be prepared and confident in questioning medication orders and evaluating patient responses to drugs. Actively advocate for the development, testing, and safe implementation of electronic health records. Work to improve systems that address “near misses” in the work environment. Realize they are part of a system and do their part to evaluate the efficacy of new safety systems and technology. Contribute to the development and implementation of error reporting systems, and support a culture that values accurate reporting of medication errors. BEFORE Administering Medication Ethics Will this medication do more good than harm for this patient at this point in time? Has the patient (or the patient’s decision maker) had a voice in the decision making process regarding use of this medication? Have they been informed about this medication and the potential risks/benefits to consider? If there are any ethical concerns, advocate for patient rights and autonomy and contact the provider and/or pursue the proper chain of command. Legal and National Guidelines Be sure the prescription/order contains the proper information according to CMS guidelines. Are there any FDA Black Box Warnings for this drug? If so, is the patient aware of the risks and what to do if they occur? This discussion should be documented. Is this a controlled substance? If so, follow guidelines for controlled substances in terms of counting, wasting, and disposal. For prescriptions for outpatient use, advocate that Prescription Drug Monitoring Program guidelines are followed. Be aware of signs of drug diversion in other healthcare team members and follow up appropriately in the chain of command. You can also directly submit an online tip to the DEA at Rx Abuse Online Reporting. Follow the Joint Commission “SPEAK UP” guidelines if you have any concerns about the safe use of this medication, including, but not limited to:  o Unclear or “do not use” abbreviations o Strategies for look alike-sound alike medications o Any other concerns for error Follow your state’s practice act regarding Scope of Practice and Rules of Conduct. Is administering this medication appropriate for your scope of practice and for this patient? If not, protect your patient from harm and your nursing license by notifying the appropriate contacts within your agency. Is this medication administration occuring during a transition of care from unit to unit, home to agency, or in preparation for discharge? If so, be sure proper medication reconciliation has been completed. DURING Administration Use the Nursing Process as you ASSESS if this drug is appropriate to administer at this time and PLAN continued monitoring. Consider lifespan and disease process implications. If you NOTICE any findings that this medication may not be appropriate at this time for this patient, withhold the medication and contact the provider. Assess if there are any cultural or social determinants that will impact the patient’s ability to use these medications safely and effectively. IMPLEMENT appropriate accommodations as needed and notify the provider. Follow National Patient Safety Goals as you correctly identify the patient and follow guidelines to use medicines safely. If this is a “high-alert” medication, follow recommendations for safe administration (such as adding a second RN check, etc.). Reduce distractions in your environment as you prepare and administer medications. Do not crush medications unless safe to do so. Follow JC and CMS standards: o Check 5 rights before administering to patient o Educate the patient about their medication o Dispose of waste controlled substances appropriately o Document appropriately AFTER Administration Continue to EVALUATE the patient for potential side effects/adverse effects, as well as therapeutic effects of the medications. Document and verbally share your findings during handoff reports for safe continuity of care. If an error occurs, file an incident report and participate in root cause analysis to determine how to prevent it from happening again.