Ch.2 Age-specific considerations in pharmacology

Pediatric dosage

(Child's BSA × Adult dosage) + 1.73 m2 =

Promoting Adherence

Nearly half of older adults fail to adhere to their prescribed therapeutic regimen!

Alert content

Older adults may have paradoxical reactions to benzodiazepines. This reaction leads to talkativeness, excessive movement, restlessness, and agitation

Reducing Polypharmacy

Polypharmacy can be reduced by encouraging patients to maintain an up-to-date, complete list of their drugs, including prescribed drugs, over-the-counter drugs, supplements, and herbs. This list should include drug dosages and the reason they are taking the drug.

Older adults are ______________ times more likely to be hospitalized secondary to adverse drug effects than younger adults.

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summary

Aging affects all pharmacokinetic phases. Older adults experience ADEs much more frequently than younger adults. Nearly 50% of older adults fail to adhere to their drug regimens. These factors play into polypharmacy, which is the use of more drugs than medically necessary. Nurses must understand the age-specific differences in pharmacokinetics and pharmacodynamics that occur at both ends of the age spectrum. Understanding these age-specific differences promotes safe drug administration and positive patient outcomes.

In which ways are pharmacokinetic components altered due to liver immaturity in young children?

Decreased protein binding & Reduced first-pass elimination

The increased incidence of ADEs experienced by older adults results from multiple factors:

Drug toxicity due to altered pharmacokinetics (e.g., decreased kidney function) Polypharmacy Multiple comorbidities Cognitive impairment Use of drugs that have a narrow therapeutic index (e.g., warfarin)

School-Age Children

Explain the procedure, allowing for some control. Provide comfort measures. Explore feelings, fear, and anger using therapeutic play. Art and age-appropriate books may help the child express fears. Set age-appropriate behavior limits (e.g., it is okay to cry, but not to bite). Use the interaction with the child to provide teaching (e.g., what a seizure is and how medication helps prevent the seizure).

The nurse is working with an 11-year-old patient to promote self-management of insulin administration. Which patient-specific education technique would the nurse use?

Explore perceptions of illness and treatment

ped dosing stuff

Initial pediatric doses—whether based on established pediatric dosages or extrapolated from adult dosages—are at best a rough estimate. Drug therapy must be adjusted based on therapeutic response and plasma drug concentrations. It is essential that pediatric patients are monitored closely for therapeutic and adverse responses. Nurses should question any medication dosage adjustment, especially those different than the reported recommended dose. Additionally, nurses should always double-check pediatric dosage calculations with a colleague (Burchum & Rosenthal, 2019; Lilly et al., 2017).

Excretion

Kidney immaturity results in decreased glomerular filtration rate and tubular secretion and resorption in infants and children. This increases the risk for drug accumulation and toxicity. Kidney perfusion may be decreased, resulting in reduced renal function, concentrating ability, and excretion of drugs.

Infants

Maintain safe and secure positioning of the infant (e.g., with parent holding, rocking, cuddling, soothing) and perform drug administration (e.g., injection) safely and quickly. Allow self-comforting measures as age-appropriate (e.g., use of pacifier or sucking on fingers). Use a calibrated dropper or an oral syringe. Give small amounts to prevent choking

Metabolism

Microsomal enzyme levels are decreased because the immature liver has not yet started producing enough, resulting in altered drug metabolism. Older children may need increased drug dosages once hepatic enzymes are produced.

Pediatric Dosing

Most drugs have not been sufficiently studied in pediatric patients to ensure safety and effectiveness. However, for drugs that do not have an established pediatric dosage, the dosage can be estimated from adult dosages. The method of conversion most commonly used is based on body surface area (BSA; Burchum & Rosenthal, 2019):

Preschoolers

Offer a brief, concrete explanation of the procedure at the patient's level and with the parent or caregiver present. Allow some level of choice and control (e.g., injection site, type of flavored drink). Provide comfort measures after the procedure (e.g., holding). Accept aggressive behavior as a healthy response but only within reasonable limits; provide an age-appropriate outlet for aggression through play. Allow the parent to provide comfort and understanding

Toddlers

Offer a brief, concrete explanation of the procedure using simple terms. Parents and other caregivers must be part of the process. Ensure the toddler is held safely and securely during drug administration (e.g., injection). Allow the toddler to choose a place or position to take the prescribed drug (e.g., sitting on parent's lap). If appropriate, disguise the drug's taste with a small amount of flavored drink or food. Accept aggressive behavior as a healthy response but only within reasonable limits. Provide comfort measures immediately after the procedure (e.g., holding). Help the child understand the treatment and their feelings about the treatment through play.

Adverse Drug Effects

Pediatric patients are at increased risk for drug toxicity due to pharmacokinetic differences in body systems, compared with adults. The following table presents select adverse drug effects (ADEs) unique to the pediatric population.

Pharmacokinetic Changes in Older Adult

Physiologic changes occur in all body systems with aging; these changes may affect the ADME of drugs. The actual clinical impact of these changes is uncertain and varies by individual.

Polypharmacy

Polypharmacy refers to the use of more drugs than is medically necessary. There is little agreement on the actual number of drugs that constitutes polypharmacy, but researchers use five drugs because this number has been associated with increased incidence of ADEs, geriatric syndromes, and increased mortality (McCuistion et al., 2018).

Adolescents

Prepare the patient in advance for the procedure, but do not use scare tactics. Allow the adolescent personal space or time alone after the procedure to enhance coping (e.g., once a seizure is controlled). Allow the adolescent time to discuss his or her feelings. Explore the adolescent's perceptions of illness and treatment; correct any misconceptions. Encourage self-care. Encourage participation in procedures as appropriate.

Which pharmacokinetic changes do adults experience with aging?

Production of microsomal enzymes is reduced Glomerular filtration rate is decreased by up to 50%

Metabolism

Production of microsomal enzymes is reduced, potentially altering drug metabolism and increasing the risk for toxicity and drug-drug interactions. A 25% reduction in liver size and a significant decline in hepatic blood flow (up to 40%) may alter hepatic metabolism.

Additional Considerations for Family-Centered Care

Provide written instructions and demonstration of proper drug administration techniques; request a return demonstration to ensure understanding. Ensure the family understands that if the drug is spilled or spit out, they must estimate the amount of drug lost and re-administer. Be sure not to overestimate the amount lost. Recommend the use of a drug administration chart/calendar to avoid missed doses or double dosing. Reinforce the need to complete antibiotics as instructed even if symptoms resolve.

Which considerations would the nurse use to promote drug adherence in older adults?

Recommend simple drug regimens Recommend keeping a drug list in purse or wallet Ask the pharmacy to provide containers that are easy to open

To reduce the incidence of polypharmacy, on which factors would the nurse educate an older adult?

Side effects of their drugs Interactions of each drug The name and appearance of their drugs Therapeutic effects of their drugs

key points pt. 2

The aging process affects all pharmacokinetic phases. ADEs are seven times more common in older adults than in younger adults. A panel of experts developed a list detailing drugs deemed to be inappropriate for use by older adults; this list is called the American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Polypharmacy refers to the use of more drugs than is medically necessary. Nearly 50% of older adult patients fail to take their drugs as prescribed. Nurses play an important role in promoting adherence through patient education.

Older adults should be educated on:

The name, appearance, therapeutic effects, and side effects of each drug Potential adverse effects and interactions of each drug When to call their health care provider or seek emergency care The importance of taking drugs exactly as prescribed and not self-medicating

Promoting Adherence

Understanding pediatric age classifications also facilitates assessment, management, and promotion of adherence through family-centered care and patient-specific education by ensuring our care and teaching are developmentally appropriate.

An 18-month-old patient has been started on chemotherapy. Which means are used to adjust the drug dosages?

-Therapeutic response -Plasma drug concentrations

Excretion

Glomerular filtration rate is decreased by up to 50% due to decreased blood flow, potentially resulting in drug accumulation and increased risk for toxicity. The number of functioning nephrons is decreased due to glomerulosclerosis.

Which family-centered education techniques would the nurse use when teaching the parents of a 12-month-old infant how to administer oral antibiotics?

Have parent soothe the 12-month-old patient Use an oral syringe to administer the drug Allow the 12-month-old patient to suck on a pacifier

Absorption

Hydrochloric acid production is decreased resulting in higher gastric pH (less acidic); this change may alter absorption of some drugs (e.g., calcium carbonate). A decline in smooth muscle tone and motor activity results in delayed gastric emptying. Blood flow to the gastrointestinal tract is reduced by 40% to 50%. The absorptive surface area in the gastrointestinal tract decreases with aging

Distribution

In adults over the age of 60, total body water declines by 10% to 15% compared with younger adults. This reduces the volume of distribution of water-soluble drugs. Fat content increases by up to 45% due to a decrease in lean body mass. This increases the volume of distribution for lipophilic drugs (e.g., diazepam). Decreased production of proteins by the liver and reduced protein intake reduce overall protein-binding sites.

Many factors increase the incidence of polypharmacy:

Increasing age Multiple comorbidities Multiple drugs needed to treat one disease (e.g., diabetes) Drug regimen changes Multiple specialist health care providers Drugs prescribed to treat side effects Use of multiple pharmacies Self-treatment with over-the-counter drugs Nonadherence

Factors increasing the risk for poor adherence include the following:

Multiple comorbidities Multiple prescription drugs Complicated drug regimens Drug packaging that is difficult to open Multiple health care providers Changes to the drug regimen Cognitive or physical impairment (reduction in memory, hearing, visual acuity, color discrimination, or manual dexterity) Living alone Recent discharge from hospital Low literacy Inability to pay for drugs Personal conviction that a drug is unnecessary or the dosage too high Inadequate patient education Unpleasant side effects

Adverse Drug Effects

Older adults are admitted to the emergency department (ED) with ADEs more often than younger adults. They are seven times more likely to be hospitalized secondary to ADEs than younger adults. Most ED admissions and hospitalizations occur due to reactions to blood thinners, hypoglycemics, and drugs used to control seizures, cardiovascular drugs, and opioids. Symptoms in older adults are often nonspecific (e.g., dizziness, cognitive impairment), making identification of ADEs difficult

Drug Complications Unique to Older Adults

Older adults are at increased risk for ADEs due to pharmacokinetic changes that occur with aging. The following table presents select complications unique to the older adult population.

Summary

Pediatric patients are at increased risk for side effects and ADEs due to pharmacokinetic differences in body systems. Additionally, most drugs have not been studied in pediatric patients. To ensure safety and therapeutic effectiveness, as well as adherence to the drug regimen, pediatric patients and their families/caregivers should be taught and supported using age-appropriate, family-centered care.

Patient Safety

Pediatric patients may have paradoxical reactions to some drugs (e.g., methylphenidate causes excitability in adults; in children it reduces activity, making it an effective treatment for attention-deficit/hyperactivity disorder [ADHD]) (Workman, 2016). Due to the risk for Reye syndrome, pediatric patients should not be given aspirin or other drugs containing salicylates (e.g., Pepto-Bismol) (Clayton & Willihnganz, 2017).

Classification of Older Adults

Persons over the age of 65 years are referred to as older adults. Older adults are a diverse and unique population. Significant differences exist among 65-, 75-, 85-, and 95-year-olds. Within the older adult population, further classifications are made (Meiner & Yeager, 2019). young-old: 65-74 years old: 74-84 years old-old: 85+ years

key points pt. 1

Physiologic differences in body systems between children and adults affect the ADME of drugs. Although the liver matures at around 1 year, children metabolize drugs faster than adults do until early adolescence. Pediatric patients are at increased risk for side effects and ADEs due to pharmacokinetic differences in body systems. Most drugs have not been studied in pediatric patients to ensure safety and effectiveness; therefore pediatric dosages are most often estimated from adult doses using the BSA method. Adherence is promoted using age-appropriate, family-centered care practices.

key points pt. 3

Physiologic differences in body systems between children and adults affect the ADME of drugs. Although the liver matures at around 1 year, children metabolize drugs faster than adults do until early adolescence. Pediatric patients are at increased risk for side effects and ADEs due to pharmacokinetic differences in body systems. Most drugs have not been studied in pediatric patients to ensure safety and effectiveness; therefore pediatric dosages are most often estimated from adult doses using the BSA method. Adherence is promoted using age-appropriate, family-centered care practices. The aging process affects all pharmacokinetic phases. ADEs are seven times more common in older adults than in younger adults. A panel of experts developed a list detailing drugs deemed to be inappropriate for use by older adults; this list is called the American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Polypharmacy refers to the use of more drugs than is medically necessary. Nearly 50% of older adult patients fail to take their drugs as prescribed. Nurses play an important role in promoting adherence through patient education.

Pharmacokinetic Changes in the Neonate and Pediatric Patient

Physiologic differences in body systems between children and adults affect the absorption, metabolism, distribution, and excretion (ADME) of drugs. These differences are most significant in neonates and infants.

Which factors increase the incidence of older adults experiencing adverse drug effects (ADEs) from drug therapy?

Polypharmacy Cognitive impairment Kidney dysfunction

Interventions to Promote Adherence

Recommend the health care provider simplify the drug regimen for the older adult (i.e., use a combination drug to reduce the number of pills the patient takes or use long-acting formulations to reduce the number of doses per day). Recommend the health care provider choose the appropriate dosage form (e.g., a liquid formulation if the patient has difficulty swallowing). Ask the pharmacist to label drug containers using a large print size and provide containers that are easy to open by patients with impaired strength and dexterity (e.g., those with arthritis). Suggest the older adult use a calendar, diary, or pill counter to record drugs to keep track of drug administration. Ask the older adult if they can afford their drugs; recommend they only use one pharmacy. Suggest the older adult enlist the aid of a friend, relative, or visiting health care professional as needed to assist with picking up prescriptions from the pharmacy and helping the older adult with drug administration. Monitor for therapeutic drug responses and side effects; encourage the patient to report if a drug is not improving the condition for which it was prescribed. Before beginning patient education, ensure the older adult is wearing eyeglasses and hearing aids if needed. Speak in a clear, low tone of voice so that the older adult can hear; sit facing the patient and limit distractions. Treat the older adult with respect; never use elderspeak. Start with the expectation that the older adult is able to learn. Use return demonstration to verify knowledge acquisition. Use large print and dark type against a light background; use a font with serifs, or "feet and tails," which makes it easier to read. Review all drugs at each patient visit; ask the patient to bring all drugs to each appointment. Instruct the patient to keep a list of all drugs and bring it to all health appointments; advise the older adult to keep a copy of the list in their wallet or purse.

Absorption

Reduced gastric acid production results in a more alkaline environment until the age of two. This may result in decreased absorption of weakly acidic drugs (e.g., aspirin) and increased absorption of basic drugs (e.g., ampicillin). Gastric emptying is slowed because of slow or irregular peristalsis. First-pass elimination by the liver is reduced because of the immaturity of the liver and reduced levels of microsomal enzymes. Intramuscular absorption is faster and irregular.

Classification of Pediatric Patients

The term pediatric covers term neonates to adolescents 16 to 18 years of age. Within pediatrics, there is further delineation -In addition to differing developmental milestones, some drugs prescribed to pediatric patients are dosed differently based on age classification. For example, neonates are prescribed amoxicillin at 20 to 30 mg/kg/day in divided doses every 12 hours

Beers Criteria

There are many medications that should be avoided in older adults due to changes in pharmacokinetics. To identify these drugs, a panel of experts developed a list detailing drugs deemed to be inappropriate for use in older adults: American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Even though the Beers Criteria has been available since 1991 (most recently updated in 2019), 20% of community-dwelling older adults continue to be prescribed drugs that appear on the list. The key here is potentially inappropriate drugs, because drugs identified in the Beers Criteria need to be interpreted taking into consideration the patient's preferences, values, and needs.

Distribution

Total body water is 70% to 80% in full-term infants, 85% in premature newborns, and 64% in children 1 to 12 years of age. These differences result in a larger volume of distribution for water-soluble drugs (e.g., phenobarbital) in the neonate and infant than in adults. Fat content is lower in young patients because of greater total body water, resulting in a lower volume of distribution for lipophilic drugs. Protein binding is decreased because of decreased production of protein by the immature liver. More drugs enter the brain because of an immature blood-brain barrier.