Pregnancy and Lactation

Question 1

What are dietary restrictions to follow during pregnancy?

Answer 1

Avoid raw, undercooked meats
Avoid fish for mercury levels
Avoid Deli meats that have a risk of Listeria

Question 2

What happens to plasma albumin levels during pregnancy?

How does this effect drug concentrations?

Answer 2

Plasma albumin concentration decreases
Increases the volume of distribution of drugs that are highly protein bound?

However: unbound drugs are more rapidly cleared by the liver and kidney during pregnancy, resulting in little change in concentration

Question 3

What happens with clearance levels during pregnancy?

Answer 3

On average, increased clearance wins out most of the time, and if major changes occur, it is usually lower maternal drug levels

Question 4

What are factors that affect movement of drugs from maternal into fetal circulation?

Answer 4

Lipophilicity
Protein binding
Molecular weight
Drug pKa
Placental CYP450

Question 5

Which factor/type of drugs can easily move into fetal circulation

Answer 5

Highly lipophilic drugs

Question 6

Why can highly protein bound drugs not reach fetal circulation

How can this be overturned?

Answer 6

Highly protein-bound drugs have a lower free fraction that is available to diffuse into the fetal circulation

Can be overturned with maintained levels for period of time (chronic use)

Question 7

Which type of protein bound drugs can cross into fetal circulation?

Answer 7

Least protein bound drugs

Digoxin and ampicillin

Question 8

How do albumin levels change during pregnancy compared to the fetus

Answer 8

there is a gradual lowering of maternal albumin, there is a gradual rise in fetal albumin

Question 9

How much does a drug need to weigh in order to cross the placenta?

Drugs that weight over ______ cannot cross the placenta

What are some examples of these drugs that can’t cross over?

Answer 9

500 daltons or less can cross the placenta

Drugs weighing 1000 daltons or more cannot

Heparin and Insulin

Question 10

What are pKa changes seen during pregnancy?

How do these changes effect drug concentrations

Answer 10

Fetal pH (7.3) is slightly lower than maternal pH (7.4)

some degree of ion trapping can concentrate some drugs on the fetal side. Drugs love acidic environments

Question 11

Which steroid can be easily given during pregnancy without the risk of fetal exposure?

Why?

Answer 11

Prednisolone

Placental CYP450 can easily convert Prednisolone to it inactive form Prednisone which prevents exposure to fetus

Question 12

When giving analgesics/anesthesia during delivery why is it important to remove baby from c-section asap?

Answer 12

Analgesics/anesthesia can easily cross the placenta and cause effects (respiratory distress)

Question 13

How soon can CYP450s (metabolism) been seen during fetal development?

Answer 13

CYP450s begin to appears as early as 14 weeks and increase throughout pregnancy

Question 14

Which antihypertensive drugs are considered safe for pregnancy?

Answer 14

Beta blockers
Methyldopa 
Hydralazine
Calcium blockers
Magnesium sulfate

Question 15

Which antihypertensives are contraindicated during pregnancy?

Answer 15

ACE or ARBs

Question 16

Which antibiotics are safe to use during pregnancy?

Which antibiotics are not safe to use during pregnancy?

Answer 16

Nitrofurantoin
Penicillin derivatives
Cephlasporins

Sulfanamides

Question 17

Which antemetics are safe to use during pregnancy?

Answer 17

Promethazine (Phergine)

Odansetrone - for serious cases

Question 18

Which drug is no longer used to suppress lactation in women?

why?

Answer 18

Bromocriptine

increased reports of stroke, MI, seizures, and hypertension in postpartum women

Question 19

What factors determine whether drugs will enter breast milk?

Answer 19

Lipophilicity
Molecular weight
Pharmacokinetics (e.g., half-life)
Protein binding
Ionization (pka)

Question 20

How do drugs move into breast milk?

Answer 20

Drugs move into breast milk both by passive diffusion and carrier-mediated transporters

Question 21

What milk to plasma ratio indicates a drug has reached the breast milk?

Answer 21

Ratio > 1

Question 22

What is considered a safe exposure value to an infant

Answer 22

Less than 10% of therapeutic dose when compared to the total amount of drug taken

Question 23

Which drugs are to be avoided in pregnancy

Answer 23

see study guide