Question 1:
Plasma volume, total body water, cardiac output and renal glomerular filtration rate all go up in pregnancy by what percentage?
A. 10%
B. 20 – 30%
C. 30 – 50%
D. 50 – 70%
Answer: C
Question 2:
These increases (in plasma volume, total body water, cardiac output and GFR) peak early in the second trimester and then return to normal by delivery.
True or False?
Answer: False
The increases (in plasma volume, total body water, cardiac output and GFR) peak during the 3rd trimester (~32 weeks) and then decrease slightly towards term, but at delivery they are still elevated compared to the non-pregnant state.
Question 3:
Penicillins and cephalosporins are renally cleared, but the increases in both renal clearance and volume of distribution in pregnancy are not sufficient to support changes in dosing recommendations.
True or False?
Answer: False
Studies have shown that standard non-pregnant dosing regimens do not produce adequate drug concentrations in either the maternal surgical sites or in the fetus to provide the necessary prophylaxis. Guidelines recently have increased their recommended dosing for normal weight women and even higher for obese women.
Question 4:
Concentrations of albumin and α-1 acid glycoprotein go down in pregnancy. This means that there is less plasma protein to bind to medications and the unbound, free fractions of drugs go up.
True or False?
Answer: True
Question 5:
Because of these changes in protein binding, for some critical, highly protein-bound medications, it is important to measure the free fraction, not total drug, during pregnancy.
True or False?
Answer: True
Question 6:
P-glycoprotein in the placenta helps to protect the fetus by metabolizing medications that try to cross the placenta.
True or False?
Answer: False
P-glycoprotein is an efflux transporter that sits on the maternal-facing placental surface. It actively transports certain drugs away from the fetus, back into maternal circulation, thereby reducing fetal exposure. It does not metabolize medications.
Question 7:
The changes in reproductive hormones during pregnancy increase the activity of some Phase II hepatic metabolizing enzymes (conjugation/biotransformation).
True or False?
Answer: True
Question 8:
The changes in reproductive hormones during pregnancy have no effect on Phase I hepatic metabolism (chemical modification).
True or False?
Answer: False
Activity of some of the Phase I hepatic metabolizing enzymes goes up in pregnancy while activity of others goes down.
Question 9:
Methadone clearance increases in pregnancy; therefore, pregnant women on methadone often require increases in their dose.
True or False?
Answer: True
Question 10:
Pharmacogenetic differences in drug metabolizing enzymes and drug transporters can affect how an individual person responds to medications during pregnancy.
True or False?
Answer: True
Presented by the PhRMA Foundation Safe and Effective Prescribing Project
For more information, please call 202-572-7756
