Pregnancy and Lactation Flashcards Preview

Pharmacology II > Pregnancy and Lactation > Flashcards

Flashcards in Pregnancy and Lactation Deck (22):
1

Pharmacokinetic changes of pregnancy

INCREASED
-plasma volume
-cardiac output
-GFR
-Body fat
-Hepatic Perfusion
-gastric pH (more alkalotic)
-Estrogen and Progesterone (increased liver enzyme activity)

DECREASED
-Albumin concentration
-Gastric emptying (slows)

2

Overview of pharmacokinetic changes

-Volume of distribution increases
-Clearance increases** (this one wins out most of the time)
-Decreased protein binding

3

Lipophilic drugs and the placenta

cross placenta more easily

4

Protein binding and fetal circulation

Less protein bound, more likely to end up in fetal circulation (ex. digoxin, ampicillin)

5

Molecular weight and crossing the placenta

Will cross if <500 daltons (ex. Warfarin)

Cross slowly if 600-1,000 daltons

Don't cross if >1,000 daltons (ex. insulin, heparin)

6

Difference and significant of fetal versus Maternal blood

Fetus blood is more acidic/lower than Maternal blood

7

What corticosteroid can be used in pregnancy and why?

Prednisolone because the placenta (CYP450) will convert this to an inactive form of prednisone

8

When performing a C-section why is it important to get baby out as soon as possible after induction of anesthesia?

anesthesia and analgesics cross the placenta well

9

When does the fetal drug metabolism system develop?

CYP450 appears at about 14 weeks and increases throughout the pregnancy

10

Examples of antihypertensive drugs safe in pregnancy

1. Beta blockers (labetolol and propranolol)
2. Methyldopa
3. Hydralazine
4. CCB (Nifedipine)
5. Magnesium sulfate

11

Which antihypertensive meds are BAD in pregnancy

ACE and ARB :(

12

Which antibiotics are safe for UTI in pregnancy

1. Nitrofurantoin
2. Penicillin (ex. ampicillin)
3. Cephalosporins

13

Why are sulfonamides avoided in pregnancy

displace bilirubin from albumin and enhance kernicterus

14

Antiemetics safe in pregnancy

1. Promethazine (Phenergan)
2. Ondasetron (if refractory)

15

Why should bromocriptine be avoided for suppression of lactation?

-increased stroke risk
-MI
-seizures
-HTN (in post partum women)

16

What does a milk-to-plasma ratio of >1 mean?

drug is concentrated in breast milk

17

Most drugs have a ratio of _______ or less in regards to milk to plasma

<1

18

What is considered a "safe" exposure index value that is commonly and arbitrarily used as a conservative cutoff for concern?

if less than 10% of a therapeutic dose for infants


(exceptions 1. drugs that cause hemolysis in infants with G6PD deficiency
2. Chemotherapy agents

19

Lithium and the placenta

can concentrate in the fetus, easily crosses placenta

20

Pain medications safe vs. unsafe

safe: Methadone, low dose morphine, intermittent low dose oxycodone

unsafe: oxycodone and meperidine in large doses

21

Drugs to avoid in pregnant ladies

1. Methotrexate
2. Lithium
3. Phenobarbital, primidone, and ethosuximide
4. Chemotherapy drugs
5. Amiodarone (affects the thyroid)
6. Atenolol
7. Nadolol
8. Tinidazole
9. Phenytoin
10. Lamotrigine
11. Carbamazepine
12. Phenobarbital

22

Which thyroid medication is used in 1st trimester versus 2nd and 3rd?

1st - PTU (risk of hepatotoxicity)
then, switch to methimazole for 2nd and 3rd