Week 2: Geriatric Pharmacology Flashcards
What is the management of the drug by the body (absorption, distribution, metabolism, excretion)?
Pharmacokinetics
As patients age, the stomach has a _____ pH.
increased
What drugs are affected by changes in absorption?
Ketoconazole, iron supplements
What are the changes that occur with absorption as one ages?
decreased surface area and blood flow to GI, decreased GI motility, increased pH
What are the changes that occur with distribution as one ages?
protein binding (decreased albumin, increase a1 acid glycoproteins and lipoproteins), volume of distribution (less total body water, higher fat content, lower lean muscle mass)
What is important about decreased albumin?
binds acidic drugs, malnourished elderly, need a lower dose of acidic protein bound drugs
What is important about increased a1- acid glycoprotein and lipoproteins?
increases inflammation, stress, injury and binds basic drugs so need higher doses of basic protein bound drugs
What drugs are affected by (decreased) albumin?
digoxin, theophylline, phenytoin, warfarin, diazepam
What drugs are affected by (increased) A1-acid glycoprotein/lipoproteins?
propanolol, quinidine, lidocaine
What is important about less total body water?
need a lower dose of hydrophilic drugs
What is important about higher fat content?
need a lower dose of lipophilic drugs
What is important about lower lean muscle mass?
digozin binds to muscle, so concentration increases as a result in increased Vd (digoxin toxicity at lower doses than expected)
Which drugs are hydrophilic?
lithium, aminoglycosides, ethanol
Which drugs are lipophilic?
phenothiazines, phenytoin, diazepam, barbiturates, propanolol
What are the changes that occur with metabolism as one ages?
reduced hepatic blood flow, reduced hepatic mass and number of functioning hepatocytes
The _____ is the primary site for metabolism of most medications.
liver… so some drugs rate of metabolism is dependent upon rate of hepatic blood flow
What is important about reduced hepatic flow?
decreased flow leads to reduced amount of drug extracted by the liver for metabolism during first pass, leading to increased bioavailability of the drug
What drugs are affected by reduced hepatic blood flow?
calcium channel blockers, beta blockers, narcotics, nitrates, tricyclic antidepressants, hydralazine, labetalol
What is important about reduced hepatic mass and number of functioning hepatocytes?
decline in Phase I and II metabolism
What drugs are affected by reduced hepatic mass and number of functioning hepatocytes?
diazepam, alprazolam, chlordiazepoxide, amitryptyline
What are changes that occur with excretion/elimination as one ages?
renal function decreases with are, creatinine clearance decreases,
What is a better indicator of renal function?
creatinine clearance
What is important about reduced renal function?
drugs and drug metabolite often remain active for longer periods, thus prolonging drug effects and increasing risk for toxic side effects… drug half life is often substantially longer
What is polypharmacy?
use of 4 or more medications by a patient.
What is the prescribing cascade?
medications prescribed to treat side effects of other medications
What is an adverse drug reaction?
any unwanted and potentially harmful effect caused by a drug when the drug is given at the recommended dosage
an injury caused by taking a medication
may occur following a single dose or a prolonged administration or result from combination or two or more drugs
What is an adverse drug event?
any injury occurring at the time a drug is used, whether or not it is a identified as the cuase
What is orthostatic hypotension?
20 mmHG systolic decrease or 10 mmHG diastolic decrease
What can PT procedures have a negative interaction on with some medications?
Procedures that cause extensive peripheral vasodilation may produce severe hypotension in the patient receiving certain drugs with the same type of effect.
