Yingling - Drug Therapy and Aging

Question 1

Neonates and Infants:

In critical situations, most often drugs are given ___________, but most drugs are given by ___________ routes.

Answer 1

intravascular, extravascular

Question 2

These conditions associated with altered ______ drug absorption.

Congenital Heart Disease
Respiratory Distress Syndrome
Congestive Heart Failure
Short Bowel Syndrome
Thyroid Disease

Answer 2

oral

Question 3

Water soluble drugs have a great distribution in neonates and infants. Why?

Answer 3

they are more water than they are muscle

Percent Body Weight that is water:

a. Neonate: 70-75%
b. Premature neonate: 85%
c. Adult: 55%

Percent Body Fat

a. Premature infant: 1%
b. Full-term: 15%

Percent of extracellular water to body weight

a. Neonate: 40%
b. Adult: 20%

Question 4

Renal Function:

GFR is ________ (higher/lower) in neonates than adults.

GFR is ________ (inc/dec) by 50% during 1st week of life.

GFR attains adult levels between 6-12 months.

Answer 4

lower

increased

Question 5

Drug Metabolism

1. For infants, there is a ________ (inc/dec) in P450 activity but activity increases rapidly.
2. Metabolism in neonate is dependent on drug tx or environmental exposure of mother.
   - enzyme induction or inhibition in the fetus
   - drugs carried in breast milk
3. Conjugation reactions __________ (increased/diminished) especially glucuronide conjugation.

Answer 5

decrease

diminished

Question 6

What 2 drugs are displaced by bilirubin?

Answer 6

Phenytoin

Indomethacin

Question 7

Child born with PDA and need medication to close it

Adverse Side Effects - what drug?

• 30% dec in GFR
• 60% fall in urine flow rate
• variable effects on electrolyte (hyponatremia)

Answer 7

Indomethacin

Question 8

Renal Effects in Infants

1. Digoxin: t_1/2 in neonates is 60-170 hr, adults 30-60 hrs
2. Furosemide:
   - most common diuretic administered
   - immature kidney has dec perfusion (receives 5% of cardiac output at birth)
   - delayed response to furosemide

Question 9

the dosing of a child should be calculated on __________.

Answer 9

surface area

Dosages by body weight can under-estimate dose

Question 10

Goal with the elderly when prescribing drugs must be to prevent _______________ reactions, a noxious or unwanted response that occurs at a dose that usually is therapeutic.

Answer 10

adverse drug reactions

Question 11

If the response to a drug is an unexpected response of the immune system, it is a ______________ reaction.

Answer 11

hypersensitivity

Question 12

Functional Changes in the Elderly

1. Cardiac: cardiac output declines 1%/yr after the age of _______
2. Renal: GFR declines 0.5%/year after the age of _______
   tubular secretion decreases 0.5-1%/year

Answer 12

30

20

Question 13

Fact.

Type A Reactions: predictable pharmacokinetics and pharmacodynamics

Type B Reactions: unpredictable, Black Box Warnings - life-threatening

Question 14

Use of __________ lowers absorption of cimetidine, digitalis, tetracycline, phenytoin.

Answer 14

antacids

Question 15

Decreased gastric acid secretion by parietal cells, raise stomach pH. This results is less absorption of __________ and __________.

Answer 15

ferrous sulfate and ketoconzaole

Question 16

V_d for lipid soluble drugs is ________ (inc/dec) d/t increased adipose tissue.

This increases t_1/2.

Diazepam, Flurazepam, Amiodarone

Answer 16

increased

Question 17

V_d for water soluble drugs is __________ (inc/dec) d/t decreased total body water (as much as 15%).

Diuretics can magnify effect causing elevated serum levels of drug.

Ethanol, Procainamide, Atendol

Answer 17

decreased

Question 18

V_d for drugs that bind to muscle is _________ (inc/dec) d/t decreased lean body mass.

Digoxin binds to muscle Na+/K+ ATPase.

Answer 18

decreased

Question 19

Half-life _________ (inc/dec) for some drugs because of decreased phase I metabolism by P450.

Diazepam

Answer 19

increased

Question 20

Plasma Protein Binding

1. Lower plasma albumin results in an increased free fraction of _________ (acidic/basic) drugs, like Warfarin & Phenytoin.
2. Protein binding can be decreased by: renal disease and low protein diets.
3. Binding displacement with concomitant use of drugs - Wargarin and acetyl salicylic acid

Answer 20

1. Acidic

Question 21

Name term.

____________ is the measurement of the functional loss of drug per unit of time (ml/kg).

Answer 21

Clearance

Question 22

True or False: Hepatic Clearance affects both Phase I and Phase II metabolism.

Answer 22

False - decrease in hepatic clearance mostly affects Phase I metabolism, NOT PHASE II.

Question 23

____________ (what organ) elimination in the elderly is diminished for:

digoxin
penicillin
gentamicin
tobramycin
lithium
tetracycline
1st generation cephalosporins

Answer 23

Renal

Question 24

Fact: Elderly have decreased muscle mass and lower creatinine production.

Question 25

Pharmacokinetics or Pharmcodynamics?

Changes in the binding of drug to receptor, receptor number or altered translation of receptor initiated responses.

Elderly:
-dec adrenergic receptor response

-dec effect of B-adrenergic agonists and antagonists (less bradycardia with propanolol)

-inc receptor response to opiates and benzos
(greater sedation with morphine or diazepam)

Answer 25

Pharmacodynamics

Question 26

Digoxin has lower _______ elimination in the elderly.

Diuretics - watch for ________ and/or ________ depletion.

Answer 26

renal

potassium or magnesium

Question 27

Psychoactive Drugs

Black Box warning for atypical and typical __________ antagonists in elderly.

____________: worsens orthostatic hypotension

____________: requires renal excretion and dose must be adjusted for renal function.

Answer 27

Dopamine

chlorpromazine

lithium

Question 28

What class of drugs is used to treat arthritis, pain and inflammation?

-GI Ulceration

• Alter renal function:
• potential to induce Na⁺ and H₂0 retention
• dec renal blood flow and GFR
• induce hyperkalemia
• impair action of certain diuretics
• LT use of analgesics can induce papillary necrosis

-Selective COX Inhibitors

Answer 28

NSAIDS

Question 29

What is the name of the Program for the FDA Medical products reporting system?

Answer 29

Med Watch Program

Question 30

Fact: Prescription Cascade - drugs for drug side effects.