Chapter 31 Medication Administration PDF

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NUR 300 Medication Administration...

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Chapter 31 Medication Administration Monday, September 14, 2020 6:55 PM

Overview of Key Concepts in Pharmacology Drug: any substance that positively or negatively alters physiologic function Medication: a drug specifically administered for its therapeutic effect on physiologic function  Can have up to 4 names: o Chemical name - describes the elements of the medication's molecular structure o Official name - name assigned by the U.S Adopted Names Council, usually the generic name o Generic name - not capitalized and often contains a prefix or suffix that helps to identify the drug class  Example: beta blockers are prescribed for cardiac conditions and their names frequently end in -olol o Trade name - brand name, registered name assigned by the drug manufacturer. Since one type of medication can be manufactured by several companies, it can have several trade names while having a common generic name Medication lists have been reported in the United States Pharmacopeia since 1820 and the National Formulary since 1898  Help protect safety by identifying medication properties that show an appropriate range of quality and purity The Pure Food and Drug Act of 1906 designated the USP and NF as the only authorities to establish drug standards including the requirement that medications be free of impurities Subsequent legislation has cont. to set standards related to meds including:  Safety  Potency  Sales  Distribution  Efficacy The FDA enforces the medication legislation and mandates that all meds undergo safety testing before being released to public Controlled substances are regulated by the Comprehensive Drug Abuse Prevention and Control Act (1970) aka Controlled Substances Act  One objective is to reduce opportunities for drugs to be diverted from legit sources to drug abusers  Mandates regulations for the handling and distribution by manufacturers, distributors, pharmacists, nurses and care providers

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Compliance is monitored by the DEA

Drugs, substances and certain chemicals used to make drugs are classified into 5 categories or schedules  Schedule I: o High potential for abuse o No currently accepted medical use in treatments in the US o Example: heroin, LSD, methaqualone  Schedule II: o High potential for abuse; may lead to severe psychological or physical dependence o Has a currently accepted medical use with severe restrictions o Example: morphine, cocaine, methadone and methamphetamine  Schedule III: o Lower potential for abuse compared to I and II, in regard to moderate dependence o Has a currently accepted medical use o Example: anabolic steroids, narcotics (hydrocodone w/ aspirin or acetaminophen and some barbiturates)  Schedule IV: o Lower potential for abuse relative to the drugs in III, may lead to limited dependence o Has a currently accepted medical use o Example: pentazocine, meprobamate, diazepam and alprazolam  Schedule V: o Low potential for abuse relative to the drugs in IV o Has a currently accepted medical use in treatment In the US o Example: OTC cough medicines with codeine Local Regulations and Institutional Policies Tracking: every time a controlled substance is purchased/dispensed, an accurate record must be kept. Inventory must be kept of all controlled substances in stock, this inventory must be reported to the DEA every 2 years Floor Stock: although not required by the CSA, many hospitals and clinics require that floor stock of controlled substances be accounted for at the beginning and end of each nursing shift Disposal: if a controlled drug needs to be wasted (ex. Only partial amount is needed for a prescribed dose), 2 licensed clinical staff members must witness the disposal of the substance and document the wasting of the drug in the appropriate manner Principles of Drug Action Pharmacokinetics: study of how a medication enters the body, moves through the body, and ultimately leaves the body

Pharmacodynamics: the process in which a medication interacts with the body's cells to produce a biologic response Understanding these helps the nurse evaluate the therapeutic, or intended, response and adverse, or unintended, effects cause by the administered medication Pharmacokinetics describes the absorption, distribution, metabolism, and excretion of a medication. Absorption: the passage of a drug from the administration site into the bloodstream. These factors affect absorption:  Route of administration  Ability of the drug to dissolve or become soluble  Blood flow to the administration site  Patient age The quickest rate of absorption is through the blood vessel (intravenous), followed by intramuscularly, subcutaneously, and orally Distribution: the process of delivering the medication to tissues and organs, and ultimately to the specific site of action. Affected by:  Chemical properties of the drug  Effectiveness of the cardiac system  Ability to pass through tissue and organ membranes  Extent to which the drug binds to proteins or accumulates in fatty tissue Metabolism: the process by which a drug is altered to a less active form to prepare for excretion  Products of this process are called metabolites; most metabolisms take place in the liver; in older individuals or anyone with impaired liver function, this process may be slowed  Must be careful when administering drugs to these populations as the toxic levels build up if the liver is not able to break down the drug to a less active form Excretion: the process that removes the less active drug or its metabolites  Most metabolites exit the body through the kidneys in urine, some may be excreted in feces, breath, saliva, sweat and breast milk  A drug may accumulate to unwanted levels in older individuals and people with impaired kidney function. Prescribing smaller doses with longer duration b/t doses may be advised Therapeutic Effect- desired result or action of a medication To achieve this, the medication must be taken into the body, be absorbed and distributed in cells and tissues, and alter physiologic functioning Can be influenced by factors such as:  Medication dose  Route of administration  Frequency of administration  Function of metabolizing organs, such as the liver or kidneys  Age

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Gender Genetics

Biologic Response Pharmacodynamics is the process in which a medication interacts with the body's cells to produce a biologic response. A biologic response can be systemic or local. Systemic:  

Some medications, via some routes, affect the whole body and effects are seen in multiple body systems An example is the biologic response seen in the administration of narcotic pain medication. Effects are noted in the nervous system (sedation), respiratory system (change in respiratory rate), and gastrointestinal system (constipation)

Local:  

Some medications, via some routes, affected only limited body areas An example is the localized effect that results when an antipruritic lotion is applied to an insect bite

Drug Action Factors Half-life - a drug's half-life is the expected time it takes for the blood concentration to measure one half of the original drug dose due to drug elimination. For example, if a drug has a half0life of 12 hours, 50% of the drug's original dose remains in the bloodstream 12 hours after administration. After another 12 hours, only 25% of the drug's original dose remains in the bloodstream.  Correct spacing of doses to maintain consistent drug levels and obtain therapeutic effects is based on the drug's half-life and is an important consideration when medications are prescribed. Onset of action - the time it takes the body to respond to a drug after administration. Onset is affected by the route of administration, the drug formulation, and pharmacokinetic factors. For example, the onset of action for insulin varies greatly, depending on the route and the type of insulin. Peak and trough levels- refers to the highest and lowest concentration of a drug in the bloodstream over time

Peak plasma level indicates the highest serum (blood) concentration of a drug   

Peak and trough levels are measured with blood tests, results are used to adjust dose amounts and monitor for toxicity Blood samples for peak serum levels are drawn at specified times after administration on the basis of a drug half-life Trough levels are drawn just before the administration of a scheduled dose

Side effects and adverse reactions Side effects: predictable, but unwanted, and sometimes unavoidable, reactions to medications  May be minor and harmless, or they can cause injury  May result in the patient refusing to continue a medication  Patient education regarding to handle expected side effects can offset these reactions  Ex. If nausea is a frequent side effect, the drug can be taken with a light meal  Nurses must be particularly alert for side effects when a new medication is started or the dose is increased

Adverse effects: severe, unintended, unwanted and often unpredictable drug reactions  An adverse effect may occur after one dose, such as a severe allergic response, or it may develop over time, such as the development of anemia associated with a medication  When an adverse reaction occurs, medication must be stopped immediately  They are reported by health care providers to the FDA by using the MedWatch program Toxic effects: result from a medication overdose or the buildup of medication in the blood, due to impaired metabolism and excretion  Toxic levels of a drug can lead to serious physiologic effects that may be deadly  Ex. Toxic levels of a pain medication, such as morphine, may cause respiratory depression, leading to respiratory arrest  Organs that can be damaged from drug toxicity include: o Kidneys (nephrotoxicity) o Liver (hepatotoxicity) o Organs of hearing (ototoxicity) o Heart (cardiotoxicity)  With careful patient care and monitoring, most drug toxicity is avoidable Allergic reactions: unpredictable immune responses to medications  Minor allergic reactions include: rash; itching of the skin; inflammation of the nasal passages, causing swelling and a clear discharge; and raised skin eruptions (hives)  A severe allergic reaction is called an anaphylactic reaction and is a medical emergency  An identification bracelet or tag identifying the allergy should be worn by patients who have experienced a severe allergic reaction Idiosyncratic reactions: unpredictable patient responses to medication  They can be: over response, under response, abnormal reaction to the medication  Ex. A patient receiving antihistamine may become overly alert and be unable to sleep, rather than being drowsy, as expected Interactions and Incompatibility

Medication interactions occur when a drug's action is modified by the presence of a certain food, herb, or other medication This interaction can alter the way the medication is absorbed, metabolized, or eliminated Synergistic effect: occurs when a drug's effect is increased in the presence of another substance in the body  Alcohol, for example, is a CNS depressant that has an increased effect when taken with antihistamines, antidepressants, or barbiturates  A synergistic effect may be specifically sought by the HCP Antagonistic effect: occurs when a drug's effect is decreased by taking it with another substance

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For example, antibiotics can lessen the effect of birth control medications, and grapefruit juice alters the absorption of statins, a class of lipid-lowering drugs

Incompatibility: mixing medications in a solution that causes precipitation, or combining a drug with another drug that causes an adverse chemical reaction  Special care must be taken to avoid incompatibility when administering parenteral medications. Compatibility must be assessed before mixing medications  If prescribed medications are not compatible, they should be administered separately following safety measures, such as flushing the intravenous tubing b/t medications Nonprescription vs. Prescription Nonprescription medications can be obtained without a HCP's authorization  Nurses need to assess pt use of nonprescription and prescription substances and provide teaching on possible interactions among the substances  Often called over-the-counter medications o Example: cold medicines, vitamins, herbal preparations, sleep aids o FDA regulates OTC meds relative to safety and recommended dosage, but does not regulate all supplements Safe use of OTC medication includes understanding:  Desired effect of the medication  Potential side and adverse effects  Possible allergic reactions  Potential interactions with other medications and herbs  Warnings  Directions and dosage  Features, such as safety caps Vitamins       

Usually acquired from food Should consider use when pregnant, breastfeeding, a vegetarian/vegan, an illness or condition that prevents oral consumption of food, and the need for dietary supplements Regulated by the FDA Body uses vitamins for the biologic processes of growth, digestions, and nerve function Water-soluble vitamins (B & C) are excreted by the body through the kidneys Fat-soluble vitamins (A, D, E, and K) are stored by the body for use as needed; however, excess can build up in the liver Can have side effects including anticoagulation, and interfering with the results of medical tests

Herbal Therapy has roots that date back to ancient times  More than 38 million people in the US reported using an herb supplement in 2007  Top 10: Echinacea, flaxseed, ginseng, ginkgo, and garlic  Often taken for specific symptoms and for a limited amount of time Echinacea  

Stimulates the immune system; facilitates wound healing; fight flu and colds Side effects and drug interactions: possible liver inflammation and damage if used with anabolic steroids or methotrexate

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Alleviates and helps prevents migraines; relieves pain of arthritis Side effects and drug interactions: increased bleeding; potentiates action of anticoagulants

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Lowers BP and cholesterol and triglyceride levels Side effects and drug interactions: increased bleeding; potentiates action of anticoagulants

Feverfew

Garlic

Ginkgo Biloba  Improves memory and mental alertness  Side effects and drug interactions: increased bleeding; potentiates action of anticoagulants Ginseng 

Increases physical stamina and mental concentration

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Side effects and drug interactions: can increase heart rate and BP; decreases effectiveness of anticoagulants

Saw palmetto  Helps with enlarged prostate and urinary inflammation  Side effects and drug interactions: interacts with other hormones St. John's Wort  Alleviates mild to moderate depression, anxiety, and sleep disorders  Side effects and drug interactions: interacts with antidepressants, birth control pills, cyclosporine, digoxin, and HIV and cancer medications

Prescription Medications- require the authorization of a HCP To be a legally valid prescription, must include:  Patient's name  Date and time order was written  Name of drug to be administered  Dosage of drug  Route of drug administration  Frequency of drug administration  Signature of the person writing the order

Acute Care Medication Orders Routine- administered until the HCP discontinues the order, or until a prescribed number of doses or days have occurred PRN- given only when the patient requires it. Use is determined by objective and subjective assessment and clinical judgement of the nurse. A PRN medication is administered as needed, but still within identified time constraints One-time/on-call- given only once at a specified time, often before a diagnostic or surgical procedure Stat- given immediately and only once in a single dose; frequently given for emergency situations Now- used when a medication is needed quickly but not as immediate as a stat medication; given one time Forms of Medication Tablet- medication is compressed with binding substances and disintegrating agents into a tablet form; may have flavoring added to improve taste; used for oral, sublingual, and buccal routes. Enteric-coated tablets have a special outer covering that delays absorption as the medication dissolves in the intestines

Capsule- medication is enclosed in cylindrical gelatin coatings. Time-release capsules have medication particles encased in smaller casings that deliver medication over an extended period Powder- ultrafine drug particles in a dry form is medication powder; depending on the medication, may be inhaled, mixed with food, or dissolved in liquids immediately before administration Troche- or lozenges are medications prepared to dissolve in the mouth Solutions- medications that are dissolved in liquid  Syrups are mixed with sugar and water  Suspensions are finely crushed medications in liquid  Elixirs are medications dissolved in alcohol and water with glycerin or other sweeteners  Drops are a sterile solution or suspension administered directly into the eye, outer ear canal, nose, or sublingually  Injectable solutions are sterile suspensions supplied in ampules, vials, prefilled syringes, bags, or bottles Inhalants- medications inhaled or sprayed into the mouth or nose. Inhalants may have local or systemic effects. Some inhalants or sprays are delivered in fixed doses Skin preparations- include ointments (spreadable, greasy preparations), creams (not greasy but used on skin only), and lotions (solutions or suspensions used on skin, and not as sticky as creams or ointments). Transdermal patches contain medication absorbed through the skin over an extended period Suppository- bullet shaped gelatin tablets commonly administered rectally or vaginally, depending on the medication. Urethral preparations are used for erectile dysfunction. Routes of Medication Administration Oral:     

Most commonly administered route Abbreviated as PO (Latin: per os, "by mouth") Designed to be swallowed with fluid Safest, most convenient, least expensive method Have slower onset of action than parenteral medications

Nurses are responsible for ensuring medications taken orally are swallowed. A patient with:  Difficulty swallowing may hold medication in mouth  Cognitive or mental health issues may pocket medication in the cheek Certain tablets may be inappropriate for patients with:  Nausea/vomiting  Simultaneous gastric suctioning  Swallowing difficulty  Certain procedures schedules Oral medications may:  Irritate GI lining

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Have an unpleasant taste Discolor teeth

Sublingual/Buccal:  Used for absorbing small amounts of medications quickly through oral mucosa; preventing its destruction by gastric or intestinal secretions  For sublingual route- medications placed under the tongue to dissolve.  For buccal route- medications are placed against the mucous membrane of the cheek until dissolved. Ex. Antiemetics and opiate pain medication  Both are more potent b/c drug bypasses the liver and enters the blood stream directly  May be inactivated by gastric juices if swallowed

Via tube:   

Oral medication can be administered through nasogastric, gastric, intestinal, and jejunal tubes Tube placement must be checked before administration Safety precautions need to be taken to prevent aspiration or clogging of the tube when administering medications through small-bore feeding tubes

Topical: 

Applied to a specific skin surface or mucous membrane of the body cavity

Nurses administer medications to the skin and mucous membranes through:  Liquids and ointments applied to the eyes  Suppositories inserted into the rectum or vagina  Fluids instilled into a body cavity, such as the eye, ear, nose, bladder, vagina, or rectum  Lotions and ointments applied to any skin surface  Spray applied to the throat Absorption is affected by the vascularity of the application site. Topical administration has local effects with systemic effects possible; dose absorption m...