Pharmacology - Chapter 5
The 68-year-old client states, "I have been taking aspirin on occasion for my arthritis for many years but notice that it takes longer for it to start working now." What is the best response by the nurse?
"As you get older, absorption is prolonged and medications may take a little longer to act than normal." Decreased organ efficiency in the older adult alters pharmacodynamic response. Because absorption is prolonged in the older adult, response to single doses of drugs is commonly delayed substantially. The older adult taking aspirin for intermittent joint pain usually experiences a longer onset of action than normal.
A nurse is conducting an assessment of a client who has recently had several changes made to the drug regimen. What assessment question most directly addresses the safety implications of the client's drug regimen?
"Do you take any herbal supplements or alternative medications?" The use of alternative medications and herbal treatments is high, and increasing; because older adults tend to take more prescribed medications than other age groups, they are at higher risk for drug interactions if they take alternative medications. Questions about the drug route, expectations for treatment, and the particular pharmacy are less directly related to the issue of safety.
An older adult client is known to be taking 14 different medications. What is the greatest risk for the client?
Adverse drug interaction; Polypharmacy is increasing even though it is known to increase the risk for drug interactions and toxicities. While the risk of financial hardship, missed doses, and nonadherence are all possible none have the seriousness of drug interactions.
The nurse educates an older adult about the seven prescribed medications to prevent medication-related reactions and adverse effects. Which client statement indicates the need for further clarification?
"The dietary supplement I used to take before admission to the hospital is all right to restart."; The older adult client has multiple comorbidities requiring multiple drugs (polypharmacy), increasing the risks for drug-drug interactions and increasing the likelihood of adverse effects. The nurse needs to clarify teaching regarding the client's misconception that continuing vitamins and dietary supplements the client took before hospitalization is fine. Some vitamins and dietary supplements may interact with medications, so this needs to be assessed. Using the same pharmacy decreases the risk of drug interactions. The client needs to ask prescriber or pharmacist whether an over-the-counter treatment will lead to an interaction or not. The client needs to report adverse reactions promptly to the health care provider.
The nurse who is caring for an older client sees that the latest laboratory report reveals a decreased creatinine clearance. The nurse anticipates what modification to the client's drug regimen?
A decrease in the dosage of medication; With a decreased creatinine clearance, it is necessary to reduce the dosage of medication.
To reduce older adults' risk of experiencing adverse drug effects or interactions, what action should the nurse prioritize?
Assess clients' use of herbal remedies and over-the-counter (OTC) medications; To prevent adverse effects, the nurse should assess clients' health history and list of medications, including prescription medications, over-the-counter medications, and herbal supplements. Clients should never be encouraged to adjust their drug dosages. A second opinion is not always necessary and may not reduce the risk of adverse effects. Assessing clients' understanding of their medications is important, but this action may or may not directly reduce the risk of adverse effects.
Barbiturates were given to an older adult man having reduced kidney function, and he nearly died as a result. The most likely reason for this near-fatality is associated with which drug characteristic?
Biological half-life of the drug; when kidney function is reduced, the biological half-life of a drug may be greatly increased, allowing it to reach levels that trigger adverse reactions. Reabsorption into the blood and kidney filtration are decreased in this client, and there is no reason to think the dosage was altered.
A nurse is aware that older adults tend to have a significantly decreased rate of hepatic blood flow compared with younger adults. What effect is this likely to have on pharmacokinetics and pharmacodynamics in an older adult?
Drug clearance is likely to be slower; An age-related decline in hepatic blood flow that begins around the age of 40 years can affect serum concentration and volume of distribution of substances that are metabolized more extensively by the liver, even in healthy older adults. This change slows the delivery of medications that normally are rapidly metabolized and result in slower clearance and elimination. The kidneys do not compensate for this phenomenon and multiple bioactive substances are not normally required to achieve therapeutic effect.
Age-related changes in the GI tract of an older adult can alter oral drug availability or affect bioavailability, as evidenced by a decrease in the systemic availability of which drug type?
Drugs that require an acidic environment; With age, the GI tract undergoes several changes that can alter oral drug absorption or affect bioavailability. For example, the stomach's response to food decreases, typified by reduced gastric acidity. Drugs that require an acidic environment to dissolve may take a longer time to disintegrate and be absorbed by the body. This delay may ultimately decrease systemic availability of a drug.
The child of an older adult client states that the client has developed a rash on the upper torso and has been taking diphenhydramine hydrochloride to relieve the associated pruritus. What question should the nurse ask the client to assess for the presence of a common side effect of this medication?
Have you been having any difficulty urinating? Diphenhydramine hydrochloride (Benadryl) is included on the Beers list due to the risk of urinary retention among older adults. None of the other options are relevant to this medication.
How is the renal system affected by the aging process?
In older adults, physiologic changes associated with alterations in medication excretion include diminished renal blood flow, number of functioning nephrons, glomerular filtration rate, and tubular secretion. In most older adults, the serum creatinine remains within normal range due to decreasing creatinine levels in association with a decrease in muscle mass.
A home health nurse is performing a home visit to an elderly client who has early-stage dementia. The nurse observes that some of the client's pill bottles are empty, even though the client is not due for refills for 2 weeks. What nursing diagnosis should the nurse prioritize when planning this client's care?
Ineffective Therapeutic Regimen Management; The possibility that the client may be exceeding the prescribed dosages suggests that the client is unable to safely manage the drug regimen. The safety risk that is posed by this practice supersedes the importance of coping or home maintenance. This problem is more likely to be rooted in the client's cognitive deficit rather than a lack of knowledge.
A 79-year-old woman who takes several medications for a variety of chronic health problems has been prescribed an oral antiplatelet aggregator that is to be taken once daily. The nurse has encouraged the woman to take the pill at the same time of day that she takes some of her other medications. What is the most likely rationale for the nurse's advice?
Integrating the new drug into the client's existing schedule promotes adherence; When new drug therapy begins, plan a new drug schedule to coincide with other prescribed schedules whenever possible. If the client already takes a drug three times a day with meals, and the new drug must be taken once a day, the client should take the new drug with breakfast when other drugs are taken. In this way, the client need not remember another time to take a drug. This kind of planning promotes therapeutic adherence. This strategy does not necessarily benefit drug metabolism or reduce the risk of adverse effects.
Why is it important for the nurse to obtain baseline information from a client, such as a drug profile, an accurate history of the client's usual abilities, and changes in abilities or health status?
Obtain a current drug profile and an accurate history of the client's usual abilities and changes in abilities or health status. By establishing this baseline information, it is possible for the nurse to be alert to any new signs and symptoms in the client that could be drug related.
What schedule of medication dosing assists older adults in adhering to a medication regimen?
Starting slow and with low doses improves adherence to the medication regimen. Starting with smaller doses minimizes adverse effects.
When should the nurse assess all the client's prescribed medications?
The nurse should perform an assessment of all medications at each visit, in all health care settings, and every time the client transitions from one setting to another, from hospitalization to discharge home, or to a long-term care facility.
A healthy 70-year-old man has been having trouble sleeping at night. Additionally, he has been having difficulties with gastresophageal reflux. He buys generic Benadryl to help him sleep and buys generic Tagamet for his reflux. After 7 days of taking these over-the-counter medications, he exhibits signs of confusion and disorientation. His wife calls the primary care facility to speak with the nurse. What should the nurse suspect first?
The older adult has been taking two over-the-counter medications, Benadryl and Tagamet, which, when taken together, produce an anticholinergic effect. Anticholinergic drugs can lead to medication-induced cognitive impairment.
What is the relation between the activity level of older adults and the response to medication?
The older adult who is more physically active is less likely to have an adverse drug effect; The more physically active older adults are, the less likely they are to experience altered drug responses.
The client's admission blood work indicates a low creatinine clearance rate (CrCl). A low CrCl may have what implication for the client's pharmacotherapy?
The patient may require lower-than-normal doses of a drug; Low CrCL implies diminished excretion, necessitating lower doses of many drugs. Alternative routes and timing do not compensate for this physiological change.
For what reason is the creatinine level alone not a good indicator of renal function in the older adult?
There is a decline in overall muscle mass, which produces a lower creatinine level; Aging can substantially decrease renal efficiency by altering the two main processes by which the kidneys remove drugs from the blood: glomerular filtration and renal tubular secretion. Both of these processes decline in efficiency with age, ultimately resulting in slower drug excretion and altered drug half-life. One of the standard markers for renal function is the serum creatinine concentration, which reflects creatinine clearance from the blood by way of glomerular filtration. Despite the decline in the efficiency of glomerular filtration in the older adult, serum creatinine levels often remain in the normal range. The normal range is maintained because creatinine production declines in the older adult as muscle mass decreases; therefore, less creatinine overall exists in the older adult to be filtered.
To reduce older adults' risk of experiencing adverse drug effects or interactions, what action should the nurse prioritize?
To prevent adverse effects, the nurse should assess clients' health history and list of medications, including prescription medications, over-the-counter medications, and herbal supplements. Clients should never be encouraged to adjust their drug dosages. A second opinion is not always necessary and may not reduce the risk of adverse effects. Assessing clients' understanding of their medications is important, but this action may or may not directly reduce the risk of adverse effects.
The ability of older adults to adequately distribute drugs that are ingested is highly dependent on serum levels of what factor?
albumin; Many medications require serum albumin to bind, transport, and distribute the medication to the target organ. In the event that the amount of serum albumin is insufficient, the amount of free drug rises and the effect of the drug is more intense. Distribution is not directly dependent on levels of sodium, creatinine, and BUN.
An elderly client comes into the clinic with a family member. The client reports back pain. The health care provider prescribes cyclobenzaprine (Flexeril) for the client. What type of adverse effects should the nurse educate the client and family about?
anti-cholinergic side effects such as sedation and weakness; Most muscle relaxants and antispasmodic drugs are poorly tolerated by elderly clients because they cause anticholinergic adverse effects, sedation, and weakness. Additionally, their effectiveness at doses tolerated by elderly clients is questionable.
An older adult client intends to supplement a prescribed anti-inflammatory with a herbal remedy that a neighbor strongly recommended. What action should the nurse encourage the client to take before initiating that plan?
checking with the health care provider before taking the supplement; To prevent potentially adverse effects, clients must be urged to liaise with their care providers before adding over-the-counter (OTC) medications or supplements to their medication regimens. None of the other options provide as well for the client's safety and avoidance of adverse effects.
The nurse should caution an older adult client against using diphenhydramine hydrochloride because of what increased risk?
confusion; Diphenhydramine hydrochloride should be avoided by older clients since it is included on the Beers list because of the risk of confusion. This medication is not known to have the risks associated with other options.
A 72-year-old man with pain issues is being given a drug by the intramuscular route. His serum blood level concentrations have been erratic. The nurse suspects that this may be due to
decreased blood flow to tissues and muscles; Decreased blood flow to tissues and muscles can alter the absorption of drugs administered subcutaneously or intramuscularly in older adults. Increased plasma albumin levels, altered gastric pH, and altered gastrointestinal motility would not affect blood concentrations.
What phenomenon is primarily responsible for the changes in pharmacokinetics that accompany the aging process?
decreased function of vital organs; Aging results in physiological changes that affect the absorption, distribution, metabolism, and excretion of medications. The most relevant physiologic change is the decreased function of vital organs needed for the pharmacokinetic processes. None of the other suggested options present such a degree of change.
A 72-year-old man who is unable to sleep since admission into the hospital is given a hypnotic medication at 9 PM. The nurse finds the patient drowsy and confused at 10 AM the next day. The nurse is aware that this behavior is most likely due to
decreased hepatic function; Decreased hepatic function may extend the half-life of a drug and increase the patient's response to the drug. Increased renal function would rid the body of the drug faster than normal and would not cause prolonged effects. A toxic effect would be a more serious effect such as inability to awaken the patient. An allergic reaction does not usually manifest itself as a confused and drowsy state.
A nurse is aware that older adults tend to have a significantly decreased rate of hepatic blood flow compared with younger adults. What effect is this likely to have on pharmacokinetics and pharmacodynamics in an older adult?
drug clearance is likely to be slower; An age-related decline in hepatic blood flow that begins around the age of 40 years can affect serum concentration and volume of distribution of substances that are metabolized more extensively by the liver, even in healthy older adults. This change slows the delivery of medications that normally are rapidly metabolized and result in slower clearance and elimination. The kidneys do not compensate for this phenomenon and multiple bioactive substances are not normally required to achieve therapeutic effect.
The mentoring nurse is orienting a new graduate RN to the geriatric floor. What assessment technique will the new graduate nurse perform to identify an age-related physiological change associated with medication metabolism?
external palpation of the liver; Age-related physiologic changes of the liver affect the metabolism of medications. At approximately 60 years of age, the liver begins to decrease in size and mass. Palpation of the liver will help assess organ size and position. While the other assessments may be focus on age-related changes, they are not associated with medication metabolism.
The nurse is aware that the most relevant way in which aging affects the pharmacokinetic process of drug administration is decreased:
function of vital organs; The most relevant physiologic change is the decreased function of vital organs needed for the pharmacokinetic process. Decreased affinity to receptor sites for medication, decreased function of the beta-receptor system, and decreased cellular biochemical reactions are all changes related to the aging process, but they are related to the pharmacodynamics area.
An elderly client has taken flurazepam for sleep and has experienced signs of a paradoxical reaction. The nurse should immediately implement what intervention?
implements fall prevention strategies; Signs of a paradoxical reaction to a benzodiazepine would include restlessness and inability to fall asleep. To minimize the risk of injury, the nurse would immediately implement fall prevention strategies. A paradoxical reaction is not a common reaction. The nurse does not administer a different medication to induce sleep while the effects of flurazepam are still active. No data support the nursing diagnosis of Ineffective Coping.
Race is a variable that is known to influence what aspect of pharmacokinetics in older adults?
metabolism; Some responses to drug therapy are genetically determined and may differ in various ethnic and racial populations. Clients of Asian descent can metabolize and excrete medications more quickly than White or Black clients. As a result, circulating levels of medication are higher in the latter populations. None of the other aspects of pharmacokinetics is impacted as dramatically. Administration route is not an aspect of pharmacokinetics.
A nurse is caring for an 81-year-old client in a long-term care facility who takes nine different medications each day. The client has a recent diagnosis of seizure disorder and has begun treatment with phenytoin (Dilantin), a highly protein-bound drug. After 1 month of Dilantin therapy, the client is still extremely drowsy and sluggish. The nurse determines that the prolonged adverse effect is likely due to:
polypharmacy decreasing the number of available protein-binding sites; Because the client is receiving nine different drugs, there are fewer protein-binding sites to start with. Each drug is competing for a site, and the Dilantin may be unable to locate a binding site. Therefore, the effects of the Dilantin therapy will increase because more free or unbound drug is available to be active. Dilantin is a highly protein-bound drug and less creatinine is available overall to be filtered. Age-related changes in the central nervous system affect the efficiency of the blood-brain barrier, not the drug itself.
The nurse knows that when caring for the older adult, there are several normal aging processes that put the client at risk for toxicity. What factor puts such clients at increased risk for drug toxicity?
reduced efficiency of renal function; Normal renal function decreases with aging. Drugs that depend on renal elimination are not excreted as quickly in the older adult. This decrease in function leads to elevated circulating active drug levels, which places the client at risk for adverse effects or drug toxicity. Reduced efficiency of the blood-brain barrier, reduced plasma protein levels, and reduced gastric acidity affect the distribution of the drug but do not directly increase risk for drug toxicity.
