Pharm ch12 part 1
Home > Flashcards > Print Preview
The flashcards below were created by user
on FreezingBlue Flashcards
. What would you like to do?
Older Americans constitute almost ___% of the population, and nurses will care for increasing numbers of older adults representing the "core business" of health care.
Geriatric pharmacology for the older adult
requires special attention to the age-related factors of durg absorption, distribution, matabolism, and excretion.
Physiologic changes in the older adult with gastrointestinal system
increased pH (alkaline) gastric secretions; decreased peristalsis with delayed intstinal emptying time; decreased motility; decreased first-pass effect
What effect do these GI changes have on drug administration?
Slower absorption of oral drugs
Physiological changes for cardiac and circulatory system
decreased cardiac output; decreased blood flow
What effect do these cardiac and circulatory changes have on medication administration?
impaired circulation can delay transportation of durgs to the tissues.
Physiological changes for hepatic system?
decreased enzyme function; decreased blood flow
What effect do these hepatic changes have on drug administration?
Drugs metabolized more slowly and less completely
Physiological changes for renal system?
decreased blod flow; decreased functioning nephrons (kidney cells); decreased glomerular filtration rate
What effect do these renal changes have on drug administration?
Drugs excreted less completely.
What is polypharmacy?
administration of many drugs together.
Whay is polypharmacy more common in older adults?
(1)multiple health care providers, (2) herbal therapy, (3) OTC drugs, (4) discontinued prescription drugs
Pharmacokinetics for the older adult:
due to decrease in both blood flow and GI motility, absorption from the GI tract is slowed. Acidic drugs are poorly absorbed because of increased alkaline gastric secretions, but enteric-coated tables dissolved in alkaline fluid can break down more rapidly. Drugs remain in GI tract longer due to decreased motility.
Have loss of protein-binding sites for drugs which causes increased circulation of free drug and increased chance for adverse drug reaction. Loss in body water, water-soluble drugs become more concetrated in the body. Increase in body fat, lipid-soluble drugs are absorbed into the fat, causing a decrease in desired drug effects.
Decreased in drug metabolism due to decrease in hepatic enzyme production, hepatic blood flow, and total liver function.
Decrease in renal blood flow and decrease in glomerular filtration rate of 40% to 50%. A decrease in renal function results in a decrease in drug excretion, thus drug accumulation results. Drug toxicity should be assessed continually while client takes drug.
Pharmacodynamics (how the drug interacts at the receptor site or at the target organ) for the older adult.
Because there is a lack of affinity to receptor sites throughout the body in the older adult, the pharmacodymanic response may be altered.
Why could there be changes in sensitivity to drug action
Older adult could be more or less sensitive to drug action because of age-related changes in the central nervous systm (CNS), changes in the number of drug receptors, and changes in the affinity of rectptors to drugs.
In the geriatric client, the compensatory response to physiologic chages is
Increased or Decreased
decreased: When a drug with vasodilator properties is administered and the sympathetic feedback does not occur quickly, orthostatic hypotension could result. In the younger adult, the sympathetic response of vasoconstriction works to avert a severe hypotensive effect
Effects of sellected drug groups on older adults
Hypnotics, diuretics and antihypersensives, cardiac glycosides, anticoagulants, antibacterials, gastrointestinal drugs, antidepressants, narcotic analgesics are drug categories for which drug effects are possible.
Sedatives are hypnotics and are precribed for insomnia. For older clients, low doses of benzodiazepenes with short or intermidiate half-lives are usually prescribed. Short term therapy is suggested.
Diuretics and Antihypertensives
For older adult, the dose is usually reduced because of dose-related side effects. Calcium blockers, angiotensin-converting inhibitors, and A-II blockers are frequently the agents of choice because of their low incidence of electolyte imbalance and CNS side effects. Alpha blockers or antagonists and centrally acting alpha2 agonists are infrequently prescribed.
Digoxin is common however, long-term use should be carefully monitored because of its narrow therapeutic range (0.5 to 2 ng/mL) and the possibility of digitalis toxicity. With close monitoring of serum digoxin levels, creatinine clearance test, and bital signs (pulse should be >60 beats/min), digoxin is considered safe.
Risk of bleeding. Warfarin is 99% protein bound; with a decrease in serum albumin, which is common among older adults, there is an increase in free, unbound circulating warfarin and potential risk for bleeding. Assessment:prothrombin time (PT) or inernational normalized ratio (INR) checked periodically, and the nurse should check for signs of bleeding.
Penicillins, cephalosporins, tetracyclines, and sulfonamides are normally considered safe for the older adult. Aminoglycosides, fluoroquinolones (quinolones), and vancomycin are excreted in the urine. These drug agents are not frequently prescribed for clients older than 75 years, and if they are prescribed, the drug dose is usually reduced.
Cimetidine (Tagamet) was the first histamine blocker or antagonist and is not suggested for the older adult because of its side effects and multiple potential drug interactions. Ranitidine, famotidine, and nizatidine may be prescribed for the geriatric client instead of cimetidine.
dose for older adult is normally 30% to 50% of the dose for young and middle-aged adults. Tricyclic antidepressants are effective but have anticholinergic properties that can cause side effects. Fluoxetine (Prozac), a bicyclic antidepressant, has fewer side effects,
dose-related adverse reactions. Closely monitor vital signs
Nonadherence with a drug regimen for older adult clients.
Frequently they fail to ask questions during interactions with health care providers; therefore the drug regimen may not be fully understood or qrecisely followed.
The nurse should plan strategies with the client and family or friends to encourage ________ with prescribed regimens.
What would you like to do?
Home > Flashcards > Print Preview