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MS2 Unit 6 Pharm > Elderly Pharm > Flashcards

Flashcards in Elderly Pharm Deck (18):

does amount absorbed (bioavailability) change with age?



how does peak serum concentration change with age

may be lower and delayed


how do drugs with extensive first-pass effect change with age?

bioavailability may increase because less drug is extracted by the liver, which is smaller with reduced blood flow


factors that affect absorption

route of administration, what is taken with the drug, and comorbid illnesses. divalent cations can affect absorption of fluoroquinolones, enteral feedings interfere with absorption of some drugs, drugs that affect GI motility can affect absorption


what happens to gastric pH when you age?

less gastric acid causing higher pH in the stomach. may impact absorption of drugs such as cations.


effects of aging on volume of distribution

decreased body water = lower VoD for hydrophillic drugs
lower lead body mass = lower VD for drugs that bind muscle
increased fat stores = higher VD for lipophilic drugs
lower plasma protein = higher percentage of drug that is unbound


why might metabolic clearance of a drug by the liver be reduced?

aging decreases liver blood flow, size, and mass. liver is most common site of drug metabolism


phase I and phase II pathways

phase I convert drugs to metabolites with greater, lesser, or the same effect as the parent compound. Phase II pathways convert drugs to inactive metabolites that do not accumulate


what phase of metabolism is preferred for old patients

phase II


other factors that affect drug metabolism

gender, hepatic congestion from heart failure, smoking


effects of aging on the kidney

decreased kidney size, renal blood flow, number of functioning nephrons, and renal tubular secretion. results in lower GFR


creatinine clearance and aging

decreased creatinine production and lower GFR leads to serum creatinine staying in the normal range, masking change in creatinine clearance!


2 ways to measure creatinine clearance

24 hour urine collection. Crockroft and Gault equation


successful pharmacotherapy

uses correct drug, prescribes correct dosage, targets the correct condition, is appropriate for the patient


most common drugs involved in ADE

cardiovascular, CNS, and musculoskeletal meds. meds with a narrow margin of safety


factors that increase risk of drug-drug interactions

increased number of meds consumed, multiple prescribers, multiple pharmacies, physiologic and pharmacokinetic changes


most common adverse effects of drug-drug interactions

confusion, cognitive impairment, arterial hypotension, acute renal failure


principles of prescribing for older patients

start at low dose, titrate upward slowly. avoid starting two drugs at the same time