N212 GERO LECTURE (MISSED) PARMA CH20./Chapter 20 Pharmacologic Management

Chapter 20 Pharmacologic Management Learning Objectives  Describe the characteristics of medication use in older adults.  List medications that are best avoided in older adults.  Identify potential risk factors for adverse drug reactions.  Describe the pharmacokinetic and pharmacodynamic changes associated with aging and the implications for drug therapy.  Recognize significant drug-drug, drug-food, and drug-disease interactions, giving specific examples of each.  State the impact that drugs may have on an older adult’s quality of life.  Describe issues related to the optimum use of psychotropics, cardiovascular agents, and antimicrobials.  Anticipate the effects of the increased availability of nonprescription and herbal remedies on patient self-management.  Identify risk factors for nonadherence, and suggest strategies to improve adherence.  List the key components of assessing older adults for addictions and related disorders.  Identify the key multidisciplinary and nursing interventions for older adults who abuse substances.  Identify the signs and symptoms of alcohol, prescription and nonprescription drug, and tobacco abuse and withdrawal in older adults, and describe the corresponding nursing interventions. Demographics of Medication Use  Drugs are important in the management of conditions and the maintenance of well-being in older adults  All drugs carry some level of risk  Important to understand how aging and conditions associated with aging can affect drug processes and actions Changes in Drug Response with Aging  Aging alters dynamic processes that drugs undergo to produce therapeutic effects  There are Pharmacokenetic (movement of drugs through the body) and Pharmacodynamic (how drugs affect the body) changes that occur with aging Pharmacokinetic Changes: Absorption  Movement of a drug from site of administration to systemic circulation  Aging is accompanied by Decreased Gastrointestinal Functioning: secretion of gastric acid, slowed gastric emptying and decreased gastrointestinal motility, decreased absorptive capacity, and decreased blood flow to stomach and intestines  Age-related changes Slow Absorption of oral drugs  The first dose of a new drug may take longer to take effect  Reduction in Subcutaneous Fat associated with integumentary changes of aging alters topical medication absorption  Changes result in impaired absorption of some medications that are administered via lotions, creams, ointments, and patches Pharmacokinetic Changes: Distribution  Movement of drug from systemic circulation to site of action  Affected by relative amounts of total body water, fat content, and protein binding  Total body water decreases with aging; results in higher concentrations of water-soluble drugs Page 1 of 19 N212 GERO LECTURE 2019.10.26 (PARTIAL) PARMA CH20  To Prevent Toxicity, reduce dosages of digoxin, lithium, atenolol, and aminoglycosides (start low and build up to therapeutic levels); increase water intake  Older adults have Decreased Lean Body Mass and increased percentage of fat compared to young adults, leading to more fat storage  Drugs such as benzodiazepines and certain anesthetics (e.g., halothane and thiopental) may have extended half-lives  Drugs that are highly protein bound—warfarin, phenytoin, furosemide, and naproxen—tend to bind primarily to albumin and only become active when unbound  With age, particularly for malnourished or frail adults, albumin levels may drop as much as 15% to 25%, resulting in increased free drug available for action Pharmacokinetic Changes: Metabolism  Reactions that transform drugs into metabolites more easily excreted  With aging there is a Decrease in Hepatic Blood Flow  This can result in a decrease in the amount of a drug inactivated before entering the systemic circulation, resulting in a greater amount of active drug, increasing the risk that standard doses of drugs may have toxic effects Pharmacokinetic Changes: Excretion  Elimination of drugs from body primarily via kidneys  With decreased renal function, Half-Life (how long it takes for the body to get rid of half of the dose) increases and drugs can accumulate to toxic levels  Important implications for older adults: renal function decreases with aging  Best indicator of renal function is Glomerular Filtration Rate (GFR) Nursing Management  Careful Patient Monitoring to assess adequacy of drug to achieve desired effect and to identify any adverse effects that can create problems for the patient  Become familiar with Signs and Symptoms of Toxicity for each drug that th