Pharmacology Ch. 2,3&6

Therapeutic drug monitoring

-Measurements of drug concentration in blood sample -Very essential in neonates, infants, children -Dosage and frequency of medications can be adjusted to maintain therapeutic level of potentially toxic drugs

Pregnancy Category A Drugs

-No increased risk of fetal abnormalities shown

Genetics

-Study of how living organisms inherit the traits of their ancestors, including function of metabolic pathways -Significant differences can occur among racial and ethnic groups

Absorption

drug transferred into the body's circulating fluids -- absorption rate depends on route, blood flow and solubility of the drug. -- heat and massage will increase absorption. -topical meds can be influenced by skin thickness and hydration.

Teratogens

drugs that cause abnormal development of fetal tissues

nocebo effect

pts negative expectations can result in a less-than-optimal outcome

placebo effect

pts positive exceptions can positively affect the outcome

Seven Rights

right patient, right drug, right dose, right route, right time, right indication, right documentation

Stat order

single order carried out immediately

Pharmacogenetics

study of how drug response may vary according to inherited differences

Incompatibility

the first drug is chemically incompatible with the second drug. -- causing deterioration when the drugs are mixed in the same syringe or solution or are administer together at the same site.

medication reconciliation

the process of comparing a patient's medication orders to all of the medications that the patient has been taking

Distribution

transported throughout the body by body fluids to the sites of action -- *Protein binding and fat solubility affect distribution* -- organs with largest blood supply received the distributed drug ore rapidly

Geriatric patients

when evaluating a new symptom, determine whether it was indued by a medication already prescribed - keep multi drug regimen simple -review if an mediations can be discontinued -assess ability to pay for medications

What are two factors that influence drug distribution?

Protein binding and lipid (fat) solubility

Side effects

reactions to medicine other than the one intended

Right Documentation

requires the nurse to immediately record the appropriate information about the drug administered - -Safety/ethical considerations -Legal considerations -Always include date/time, drug name, dose, route, site of administration

Half-Life of Drugs

the time it takes for the amount of drug in the body to decrease to one half(50%) of the peak level it previously achieved

Pregnancy Category D Drugs

there is evidence of fetal risk but the benefits from use in pregnant women may be acceptable despite risk

Drugs Known to be Teratogenic

-Androgenic and estrogenic hormones -ACE inhibitors, ethanol, tetracycline -Thalidomide, vitamin A, warfarin -Angiotensin II receptor antagonists -Anticonvulsants, antimanic agents, antithyroid -Chemotherapy, statins, cocaine

Clinical Goldmines

-Approach the patient in a firm, kind manner -Give honest answers -Measure doses accurately for children -Praise children after medication administration -Don't attempt to give oral drugs to a comatose patient -Don't leave drugs at the bedside to be taken later (some exceptions) -Provide the patient with written instructions in language understood by the patient -Describe symptoms to be reported to the physician

Alterations in Metabolism

-Drug interactions are caused by an alteration in metabolism, by inhibiting or stimulating the enzymes that metabolize a drug -Some medications increase another medication's actions, contributing to toxicity Some medications decrease another medication's actions, decreasing effectiveness

Unbound Drugs

-Drugs are bound to proteins in the blood during transportation -The more a drug is "bound" to a protein, the less available it is to the circulation -Some medications can cause binding or unbinding of another medication, increasing or decreasing its effect

Drug Disposal

-Environmental concerns regarding drugs contaminating water prompted guidelines for disposal of medications in 2007 -Do not flush prescription drugs in toilet (unless instructed by manufacturer) -If no instructions are given, throw in trash -Utilize drug take-back programs, which allow public to dispose of unused drugs

drug distribution system

-Floor or ward stock system is used primarily in small hospitals. -Computer-controlled dispensing system is the safest and most economical method of drug distribution used today. -Preventing medication errors has been the primary goal of computerized drug distribution systems.

unit dose distribution system

-Single unit package of drugs dispensed into labeled drawers assigned to patients -Advantages Less prep time by nurses Pharmacy review Less wastage -Disadvantage Pharmacy, not nurse, prepares some medications

Right time

-Standard abbreviations for specific times -Standardized administration times to maximize drug absorption -Maintenance of consistent blood levels; generally laboratory tests used -PRN medications determine the last time given

Nurse Responsibilities

-Verification Nurse makes professional judgment regarding medication orders Includes type of drug, usual dose, therapeutic intent, potential allergic reactions, contraindications -Transcription -Nurse is responsible for verification of orders transcribed by others

Pediatric patients

-dosage adjustments expected during growth -measure liquid medications using mL -use appropriate dilution -verify dosage prior to giving -aspirin use linked with Reye's syndrome -Allergic reactions occur rapidly in children

Factors affection drug action

Absorption - process by which drugs are absorbed in the body (most common is via GI tract) premature - slower gastric emptying time may allow increased absorption neonates - IM absorption erratic, reduced gastric acidity infants - topical absorption increased

enteral route

Administration of drugs via the gastrointestinal tract by oral, rectal or nasogastric routes

A patient reports postoperative pain, and the nurse administers morphine (a narcotic analgesic) intravenously to ease the pain. Fifteen minutes later, the nurse notes that the patient is very drowsy, respirations are slow and shallow, and oxygen saturation is low. The nurse administers another drug that decreases the action of the morphine. What is this effect called?

Antagonistic -- Rationale: The morphine had a greater-than-desired effect on the patient. Because the drug was given intravenously, it is impossible to remove the drug from the patient's bloodstream. Therefore, the nurse does the next best thing and administers another drug that interferes with the action of the first, otherwise known as an antagonistic effect. The result is a decrease in the action of the original drug. The second drug is sometimes referred to as the antidote to the first.

Factors Affecting Distribution

Depends on pH, body water concentration, fat tissues, protein binding, cardiac output, and blood flow -Geriatric pts : total body water content decreases -Gender : total body fat higher in females

Right indication

Determine if the patient has the actual condition the drug is intended to treat. If not, question the drug order.

Narcotic Control Systems

Discrepancies are carefully checked; if the inaccuracy is not resolved by checking the patient's chart, the pharmacy and nursing service is notified

Excretion

Drug metabolites and the drug itself are excreted from the body. -preterm infants have 15% of the renal capacity of an adult -Neonates have 35% -Full adult function occurs at 9 to 12 months -Geriatric: decreased renal blood flow, reduced cardiac output, loss of glomeruli, decreased tubular function -Serum creatinine levels give estimate of renal function

Liberation

Drug released from dosage form and is dissolved in body fluid. Converting oral drug can be influenced by food and water in stomach.

Excretion

Elimination of drug metabolites and some active drug from the body -- kidneys are the major organ of excretion - some excreted in feces (pt with poor kidney function will have an increased action of duration of a drug)

Gender and Absorption

Females - stomach empties more slowly, gastric pH greater, alcohol absorbed faster

Factors Affecting Distribution: Infant test

Higher total body water content, requiring higher dose on mg/kg basis, lower body fat and reduced protein binding in neonates

Desired effect

Intended response to a medication

Computer-controlled medication dispensing systems are being used in many hospitals. Which statement about this type of system is true?

It is a safer way to dispense controlled medications - Rationale: An electronic system still needs a pharmacist to verify the order. This system controls the access to medications and allows for a detailed account of controlled substances, including who has access to the drugs. It controls the medications better than if many people have access to a shelf of medications. They also save time by eliminating the need for nurses to count every controlled drug at the end of each shift and be responsible for keys to the narcotics cupboard.

Pregnancy Category B Drugs

No evidence of risk to animal fetuses but no well-controlled studies in pregnant women

The nurse is making rounds with a patient's physician when the physician gives the nurse a verbal order for a routine medication. What does the nurse do next?

Obtains the chart and asks the physician to enter the order - Rationale: The practice of verbal orders should be avoided whenever possible to prevent medication errors. Asking the physician to place the order communicates the need professionally and clarifies the unit policy. By refusing or not following the order, the patient's care may be compromised.

Drug accumulation

Occurs when the next dose is given before the previously given drug has been metabolized or excreted. *May result in drug toxicity.

A nurse working on a busy unit is passing the medication room when another nurse approaches, states she is needed in another room, and asks for help administering medications to her patients. She hands the nurse two syringes and three unit-dose tablets and says they are for the patient in room 386. What does the nurse do next?

Offers to take care of the other patient situation and has the nurse administer her own medications - Rationale: A nurse must not administer a medication that another nurse has drawn up. The nurse must always follow the seven rights of administration to ensure complete accuracy of medication administration. If a situation of unsafe nurse-patient ratio exists, then the charge nurse should be involved.

Medication Error

Prescribing errors, transcription errors, dispensing errors, administration errors, monitoring errors, adverse drug events(costly errors), Using CPOE, barcoding, smart pumps, and other technologies helps to prevent errors

It is important to maintain therapeutic levels of drugs to avoid the complications of being over- or undermedicated. If a drug level of 0.5 to 2 ng/mL is considered therapeutic, a drug level of 0.45 ng/mL is considered to be what?

Sub-therapeutic - Rationale: Drugs are therapeutic when maintained within the normal range for the drug. In this example, the level is below that indicated for the drug, or subtherapeutic. A subtherapeutic level would require increasing the dose for the patient to achieve the maximum benefit of the drug.

Contents of patient charts

Summary sheet; Consent forms; Physician's order form; History and physical examination form; Progress notes; Critical pathways; Core measures; Nurses' notes; Nursing care plans; Laboratory tests record; Graphic record; Flow sheets; Consultation reports; Other diagnostic reports; Medication administration record (MAR); PRN or Unscheduled medication record; Case management; Patient education record; Kardex records

computer controlled dispensing system

System of inventory control that allows nurses to access medications from a central locked unit by utilizing a password.

Breastfeeding Infants

Take medicine immediately after breastfeeding or just before infant's longest sleeping period

Due to the decreased protein-binding capacity in preterm infants, what adjustment in dosage of protein-binding drugs would need to made?

The dosage should be increased - Rationale: Drugs that are relatively insoluble are transported in the bloodstream bound to plasma proteins (albumin and globulins). There is a decreased affinity for binding in infants, especially preterm infants. These drugs are then distributed over a wider area of the neonate's body. They will therefore require a higher dosage of these medications in order to achieve a therapeutic effect.

Which type of topical drug is more readily absorbed by infants?

Water-soluble - Rationale: Topical administration with percutaneous absorption is usually quite effective in infants because the outer layer of skin is not fully developed. Because the skin is more fully hydrated at this age, water-soluble drugs are absorbed more readily.

ADME

absorption, distribution, metabolism, excretion

A in ADME

absorption--> depends on route of admission will affect rate and solubility -- drugs won't take effect as quickly as IV

Pregnancy Category C Drugs

animal studies showed an adverse effect; but no studies done in pregnant women or animals

Percutaneous route

applied to and absorbed through the skin and mucous membranes (inhalation, sublingual or topical)

Verbal orders

avoid whenever possible

The main advantage of using barcode scanning devices is:

being the final safety check after the nurse has verified essential information. - Rationale: Computerized handheld devices are gaining in popularity due to their ability to decrease the medication error rate in hospitals. The nurse holds the primary responsibility to see that patients receive the proper medications.

synergistic effect

combined effect of two or more drugs is greater than the effect of each drug alone

standards of care

developed by each states nurses practice act, state and federal law, the joint commission, professional organizations

additive effect

two drugs with similar actions are taken for an increased effect

Adverse effects

unintended and usually undesired effects that may occur with use of the drug

drug dependence

unable to control his/her ingestion of drugs -physical: person develops withdrawal symptoms if drug withdrawn -psychological: person is emotionally attached to a drug

Idiosyncratic effect

unusual, unexpected response to a drug that may manifest itself by overresponse, underresponse, or response different from the expected outcome

Polypharmacy

use of multiple medications

PRN order

"as needed" order for medication

Drug level

Determines the amount of drug present

Alterations in Absorption

- Most drug interactions that alter absorption take place in the GI tract • Antacids increase the gastric pH and can inhibit the dissolution of ketoconazole tablets -Many alterations in absorption can be managed by separating the times of administration

Right dose

-Abnormal hepatic or renal function(may require a decreased in dosage by the prescriber) -Any nausea and vomiting(may affect dose patient actually absorbed) -Accurate dose forms -Accurate calculations -Correct measuring devices

Before administering medication the nurse must have:

-current license to practice -clear policy statement authorizing the act -signed medication order -understanding of rationale for drug use -understanding of drug action, dosing, dilution, route and rate of administration, common and serious adverse effects, and contraindications

A patient is being started on a new drug that has been used safely by many people for years. The patient has no known allergies, and the nurse administers the drug correctly. Suddenly the patient experiences cardiac arrest. What is this type of reaction called?

Allergic reaction --Rationale: Because the drug was a known safe drug and the patient had no known reason not to receive it, the response to the drug in this case was totally unexpected, or idiosyncratic. An allergic response is typically preceded by such reactions as rash, hives, tingling, or swelling.

allergic reaction

An immunologic hypersensitivity reaction resulting from the unusual sensitivity of a patient to a particular medication; a type of adverse drug event.

displacement

displacement of the first drug from protein binding sites by a second drug increases the activity of the first drug because more unbound drug is available.

D in ADME

distribution--> depends on circulation to be transported throughout the body -- blood and lymph systems affect drugs transport

Right Drug

Compare exact spelling and concentration of drug with medication card and drug container; drug label should be read three times

Onset of action

Concentration of a drug is sufficient to start a pharmacologic response

Factors Affecting Absorption

Geriatric pts - IM absorption erratic, reduced salivary flow makes swallowing difficult, transdermal absorption hard to predict, Timed-release/enteric-coated tablets cannot be crushed, reduced GI acidity affects absorption, slower gastric emptying time and decreased GI motility and blood flow.

Right patient

Id bracelet checking, considerations for pediatric and older adult pts.

Which patient has the greatest percentage of body water?

Infant - Rationale: An infant has a total body water percentage of 74%, whereas a premature infant has an even higher percentage at 83%. As we age, our total percentage of body water decreases and our percentage of total body fat increases.

Right Route

Know the correct route of administration by which the drug should be given - oral, subcutaneous, intramuscular(IM), Intravenous(IV)

Long-Term Care Unit-Dose System

Medication delivery cart designed with individual drawers to hold one patient's medication containers for 1 week.

Single order

Medication that is to be given only once, and at a specific time.

Teratogen

any factor that can cause a birth defect

parental route

bypasses the GI tract by using subcutaneous, intramuscular and intravenous injection

E in ADME

excretion--> depends on GI tract(BM) and kidneys(urine)--since kidneys are a major organ of drug excretion -review pts chart for results of urinalysis and renal function test.

Interference

first drug inhibits the metabolism or excretion of the second drug, thereby causing increased activity of the second drug

Standing order

given for a specific number of doses

Duration of action

how long the drug has a pharmacologic effect

Pregnancy Category X Drugs

in animals or pregnant women have demonstrated positive evidence of fetal abnormalities. Use is contraindicated during pregnancy

M in ADME

metabolism--> depends on enzyme system -- Liver is the primary sites for metabolism

antagonistic effect

one drug interferes with the action of another

Metabolism

process where the body inactivates drugs - primary organ of metabolism is the liver -- other sites are GI tract and lungs

Factors affecting metabolism

process whereby the body inactivates medications- primarily occurs in the liver.

Monitoring parameters : pregnant women

-avoid drugs, try nonpharmacologic treatments before using medicines, avoid herbal medicines, avoid drugs, alcohol, and tobacco

When the nurse administers a 50-mg dose of a drug with a half-life of 6 hours, how many milligrams will remain in the body at 24 hours?

3.13 mg -- Rationale: The half-life of a drug is the time required for 50% of the drug to be eliminated from the body. In this example at 24 hours, 6.25% or 3.13 mg of the drug would remain in the body. (divide 50 four times)

Carcinogen

A cancer-causing substance

Peak action

A drug reaches the highest concentration