Therapeutics

Question 1

most important period of organ and fetal development (most sensitive to drugs)

Answer 1

first trimester

Question 2

most common prescription drugs prescribed to pregnant women

Answer 2

oral contraceptives, amoxicillin, progesterone, albuterol, promethazine, and estrogenic compound

Question 3

most common OTC drugs prescribed to pregnant women

Answer 3

acetaminophen, ibuprofen, decussate, pseudo ephedrine, aspirin, naproxen

Question 4

factors that affect drug transfer across the placenta

Answer 4

• molecular weight of drug
• pKa of drug and degree of ionization
• protein binding of drug
• placental drug transporters

Question 5

most drugs have a mol. Wt of… and therefore …

Answer 5

<500D; most drugs cross over to fetal circulation

Question 6

how does pKa of the drug and degree of ionization affect drug transfer across placenta?

Answer 6

ionized drug transfers incompletely across; they become trapped (not always true for drugs like ampicillin and methicillin which are strong acids and are ionized but have lipophilic groups that allow transfer)

Question 7

drug transporters

Answer 7

like P-glycoprotein, breast cancer resistance protein(BCRP), and multidrug resistance protein (MRP) protect the fetus by efflux of drug from fetal to maternal circulation

Question 8

FDA Classification - Category A

Answer 8

safe

Question 9

FDA Classification - Category B

Answer 9

likely safe, animals OK

Question 10

FDA Classification - Category C

Answer 10

uncertain, risks vs benefits

Question 11

FDA Classification - Category D

Answer 11

likely unsafe risk vs benefit

Question 12

FDA Classification - Category X

Answer 12

unsafe, do not use

Question 13

Why is there more data on drug use in the age groups young and middle aged adults?

Answer 13

clinical trials are normally performed on them and patients at the two extremes (children and elderly) range markedly in their response to drugs

Question 14

why do children and elders respond differently to drugs?

Answer 14

difference in physiology makes dose adjustments necessary

Question 15

Variability in pharmacokinetics can be expected to be greatest when…

Answer 15

body physiology is changing (in newborns or premature baby or during puberty)

Question 16

In premature and newborn babies, what is necessary for sake and effective treatment?

Answer 16

dose adjustment and therapeutic drug monitoring for drugs with narrow therapeutic indices to prevent toxicity

Question 17

T/F: Drug clearance values vary linearly with either body weight or body surface area.

Answer 17

FALSE- a one year old infant will not necessarily have lower clearance compared to a ten year old for all drugs

Question 18

Hepatic drug metabolizing enzymes are …. in infants, especially in premature infants

Answer 18

not fully developed

Question 19

Clearance values of most drugs are … in children and adults

Answer 19

different

Question 20

Most drug-metabolizing enzymes are expressed….

Answer 20

at low levels at birth

Question 21

CYP3A4 is expressed… in infants

Answer 21

1 week: administering a drug metabolized by it before it is expressed is likely to produce toxicity

Question 22

newborns and glucoronic acid

Answer 22

they are unable to conjugate glucoronic acid during phase 2 metabolism

Question 23

Renal elimination of drugs is reduced in neonates, therefore..

Answer 23

dosing for drugs should be reduced to account for reduced renal clearance to avoid toxicity (e.g. amino glycoside antibiotics)

Question 24

GFR is only… in neonates and …. in adults.

Answer 24

2-4mL/min/1/73m^2; 100-130ml/min/1.73m^2

Question 25

GFR increases to adult levels by… of age

Answer 25

8 to 12 months

Question 26

Antihistamines and barbiturates in adults and children

Answer 26

• sedation in adults

- hyperactivity in children

Question 27

Children have increased sensitivity to sedating effects of propofol, resulting in…

Answer 27

cases of overdoses with myocardial failure, metabolic acidosis, and multiorgan failure

Question 28

glucocorticoids

Answer 28

can attenuate linear growth of bones

Question 29

Elderly take … of drugs prescribed to all age groups

Answer 29

1/3

Question 30

Elderly take an average of..

Answer 30

5 drugs

Question 31

Elderly report … of drug adverse reactions of all age groups.

Answer 31

25%

Question 32

Common physiological changes that affect pharmacokinetic and pharmacodynamic responses to drugs in elderly:

Answer 32

• reduction in lean body mass
• reduction in serum albumin
• reduction in total body water
• increases % of body fat (increase volume of distribution of lipid soluble drugs)
• kidney/liver function

Question 33

GFR declines at an average of … after the age of 30 years

Answer 33

0.8 ml/min/1.73m^2

Question 34

decline in GFR is an indicator of…

Answer 34

renal function

Question 35

When does the decline of GFT accelerate?

Answer 35

after age of 65-70

Question 36

an average 85 year olds GFR

Answer 36

55-60… approximately 50% decrease from age 30

Question 37

Elderly people over the age of 75 can be expected to have…. (renal clearance)

Answer 37

significantly reduced renal clearance of drugs and therefore carefully calculated dose reduction of drugs

Question 38

Elderly people can be expected to have…. (hepatic)

Answer 38

• reduced hepatic blood flow and drug metabolism with great variability between individuals
• reduced hepatic CYP activity(conjugating enzymes not affected)
• more susceptible to CNS depressants and psychotropic drugs to produce more hypotension