What is the frequency of adverse reactions and drug interactions in the older adult?
3-7 times greater than middle-aged and young adults
How does drug toxicity occur in the older adult?
May develop for dug dose that are w/in therapeutic rug range for younger adult. These ranges are safe for younger adults but not within range or older adults
What are the physiologic changes that occur in the older adult that have a major effect on drug therapy? (Table 8-1)
*increased pH (alkaline) gastric secretions.
*decreased peristalsis with delayed intestinal emptying time.
*decreased first-pass effect
= slower absorption of oral drugs
Cardiac & circulatory
*decreased cardiac output
*decreased blood flow
=Impaired circulation can delay transportation of drugs to the tissues.
*decreased enzyme function
*decreased blood flow
= drugs metabolized more slowly and less completely.
*decreased blood flow
*decreased functioning nephrons
=drugs excreted less completely.
What is polypharmacy and why is it more common in older adults?
Administration of many drugs together.
Is more common in older adults bc of the use o :
(1) multiple health care providers
(2) herbal therapy
(3) OTC drugs
(4) discontinued prescription drugs
What are the parameters of pharmacokinetics in the older adult? (Table 8-2)
Absorption, Distribution, Metabolism, & Excretion
*Decrease in gastric acidity alters absorption of weak acid drugs such as aspirin, but enteric-coated tablets dissolved in alkaline fluid can break down more rapidly.
*Decrease in blood flow to the GI tract (40%-50% less) is caused by decreased cardiac output. Bc of reduced blood flow, absorption is slowed, but not decreased.
*Reduction in GI motility rate (peristalsis) may delay onset of action.
*Reduction of gastric emptying time occurs.
*Because of a decrease in body water, water-soluble drugs are more concentrated. Increase in fat-to-water ratio in older adult; fat-soluble drugs are stored & likely to have decreased effect. Decrease in circulating serum protein. Acidic drugs (NSAIDs, aspirin, warfarin) bind to albumin; basic drugs (beta-adrenergic blockers, antidepressants, lidocaine) bind to alpha, acid glycoprotein. With fewer protein-binding sites, there is more free drug available to body tissue at receptor sites
*Drugs with high affinity for protein (>90%) compete for protein-binding sites with other drugs
*Drug interactions result because of lack of protein sites and increase in free drugs
*Decrease in hepatic enzyme production, hepatic blood flow and total liver function. These decreases cause a reduction in drug metabolism
*With reduction in metabolic rate, t1/2 o drugs increases; drug accumulation can result and lead to toxicity
*Decreases in renal blood flow and decrease in glomerular filtration rate. A decrease in renal function results in a decrease in drug excretion thus drug accumulation results. Drug toxicity should be assessed continually while the pt takes the drug
What are the changes in pharmacodynamics in the older adult?
The older adult could be more or less sensitive to drug action because of age-related changes in CNS, changes in number of drug receptors and changes in affinity of receptors to drugs
What should the nurse advise the older adult about herbal preparations?
Consult dr before starting any herbal regimen. Any herbs interact with many drugs that older pts take
Why is nonadherence a problem in the older adult population?
Older adults fail to ask questions during interactions w/hcp therefore drug regimen may not be fully understood and precisely followed.
Nonadherence can cause underdosing or overdosing that could be harmful to pts health
How can the nurse encourage adherence to prescribed medication regimens?
Daily contact may be needed at first
Nurse can work with patient family and friends to encourage adherence
Should fill Rx at one pharmacy so drug interactions can be identified and monitored closely
In relation to the nursing process, what would the nurse assess when delivering medications to the older adult?
Page 95 Assessment
What would be some nursing diagnoses related to medication administration and the older adult?
Risk for constipation r/t analgesics
Urinary retention r/t dug therapy
Imbalanced nutrition, less than body requirements r/t metabolism of drugs
Ineffective health maintenance r/t lack of transportation
Deficient knowledge r/t lack of understanding about reason for taking med
Noncompliance r/t lack of insurance with prescription drug coverage
What nursing interventions would the nurse utilize to deliver medications to the older adult?
What client teaching would the nurse provide related to medication administration to the older adult?
What cultural consideration would the nurse utilize during medication administration to the older adult?
What would the nurse evaluate after a medication has been administered to an older adult?
Evaluate compliance with drug regimen and answer qs
Evaluate drug effect, and ascertain side effects or adverse reactions