Antenatal and Prenatal Pharm - Fitz Flashcards Preview

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Flashcards in Antenatal and Prenatal Pharm - Fitz Deck (38):
1

Rating pregnancy categories of drugs does NOT take into account what?

Does not account for risks via breast milk spread of drugs or metabolites

2

Can drugs in classes C or D cause harm in pregnancy?

YES, just not to everyone

3

LAST organ to properly develop for extra-uterine life?

Problem with this?


Example of case where this will be relevant?

Lungs

Surfactant deficiency is common in premature babies (before 32 weeks), leading to RDS

Pre-eclampsia/HELLP --> preterm C-section

4

A mother has pre-eclampsia at 30 weeks (or any case requiring pre-term delivery) and requires pre-mature C-section. What is the baby at risk for?

Drug to give to help prevent this? When?

Which ones are ok? Why?

MoA?

RDS (surfactant deficiency)

Corticosteroids - PRIOR to delivery (antenatal)

Betamethasone or Dexamethasone -- no mineralocorticoid action

Binds GCR, causing inhibitor (hsp90) disassociation, then translocation of active GCR into the nucleus, then transcription of surfactant in TYPE 2 pneumocytes

5

Risks of antenatal corticosteroids - single vs. multiple courses

Single course = NONE

Multiple courses = growth defects, sepsis, brain delay, adrenal insufficiency, enterocolitis, etc.

6

Contraindications of antenatal corticosteroids

Mother w/ TB or systemic infection

7

Why is simple cortisol not given in antenatal period for premies?

Inactivated by 11-beta-HSD2 in the PLACENTA, thus fetus only gets CORTISONE

8

Describe physiology of labor induction

- Estrogen (ovaries) induces oxytocin receptor expression on uterus
- Stretch receptors in uterus cause oxytocin release (P. pituitary)
- Oxytocin causes BOTH uterine contraction AND PGF2-alpha release (placenta), which ALSO stimulates uterine contraction

9

What is the function of PGE2 in labor?

Cervical ripening

10

Drugs required for inducing labor (w/ MoA)

Dinoprostone (PGE2) or Misoprostol (PGE1) = cervical ripening

Oxytocin = uterine contractions

11

How is Dinoprostone administered?

Side effects?


So?

As suppository by the cervix

Diarrhea (stimulation of GI smooth muscle too) or uterine hyperstimulation

Has string attached to suppository for easy removal if side effects are bad

12

A deficit (natural or induced) in PGs will cause what in a pregnant woman?

An excess (natural or induced) in PGs will cause what in a pregnant woman?

Delayed birth


Premature labor/birth

13

What else is being monitored when using oxytocin for labor induction?

Fetal heart strength -- oxytocin diverts blood from fetus to uterus, thus testing the fetal heart capability to respond

14

Tocolytic drugs - what are they?

One to use in Pre-eclampsia/HELLP? Why?

Labor-delaying drugs


Magnesium Sulfate -- protects from seizures in eclampsia

15

4 different MoA's of tocolytic drugs

- Beta-2 agonists
- Ca++ channel antagonists
- COX inhibitors
- Oxytocin receptor antagonists

16

Where does COX come from in labor induction?

Placenta and myometrium

17

COX-1 inhibitors used as tocolytics

MoA

Indomethacin
Ibuprofen

Inhibit COX-1, thus reduce PGE2 and PGF2-alpha synthesis, thus reduce uterine contractions

18

Oxytocin receptor antagonist used as tocolytic

MoA

Atosiban

Reduce uterine contractions

19

Ca++ channel blockers used as tocolytics

MoA of each

Nifedipine
MgSO4

Nifedipine = directly inhibit voltage-gated L-type Ca++ channel entry into myometrium

MgSO4 = competitive inhibitor at Ca++ chanels

20

Beta-2 agonists used as tocolytics

MoA

Ritodrine, Terbutaline, Salbutamol

Increased intracellular cAMP --> reducing uterine contractions

21

Beta-2 agonists - side effects

Tachy, hypotension, HYPOKALEMIA, HYPERGLYCEMIA

22

Indomethacin -- used when (as tocolytic)?

Side effects (mother and fetus)

2nd trimester ONLY

Fetus -- facial defect (1st trimester), premature closing of ductus arteriosus (3rd trimester)

Mother -- bleeding, ulcers

23

Ca++ channel blockers - side effects

Nifedipine -- dizziness, hypotension

24

MgSO4 -- contraindication

Myasthenia gravis

25

Physiology of DA closure

Inactivation of PGE2, causing closure

26

Drug used to maintain PDA

In who?

Alprostadil (PGE1)

Congenital heart disorders (cyanotic, low PO2, need additional blood flow to heart) -- until they can be cured surgically

27

Side effects of Alprostadil


Limiting effect of Alprostadil administration

Hypotension, tachycardia, apnea, PYREXIA (fever)

Fever

28

Drug used to close PDA

In who?

Indomethacin (NSAID)

PREMATURE infants that can't close the DA on their own

29

A woman gives birth to a baby at term (40 weeks). The baby's PDA does not close at birth, and the baby begins to develop LE cyanosis and RVH. Treatment?

Surgery (NOT an NSAID - too late)

30

Indomethacin (as PDA closer) -- side effects

Renal vascular constriction (no COX-1) --> oliguria, edema, high creatinine, mild hypertension

31

Any drug that is cleared _____ must be a reduced dose in kids under 6 months

Renally

32

Sulfamethoxazole in infants

CONTRAINDICATED -- kernicterus (inhibits ability to clear bilirubin in kids)

33

Chloramphenicol in infants

CONTRAINDICATED - gray baby syndrome (V/D, circulatory collapse, abdominal distention, dusky gray color

34

Class B antibiotics (pregnancy) - ok to use

Cephalosporins, Penicillins

35

Class C antibiotics (pregnancy)

Risk?

Fluroroquinolones, Trimethoprim

Birth defects

36

Class D antibiotics (pregnancy)

Risk?

Tetracyclines

Fatty liver (mother) hepatotoxicity

37

Antibiotics contraindicated in children...

Under 8?
Under 18?

Under 18 = Fluroroquinolones (floxacin) (cartilage erosion)

Under 8 = Tetracyclines (bone and teeth deposits) AND Fluoroquinolones

38

Trimethoprim -- why contraindicated in pregnancy?

DHFR inhibitor = deficient folate = BIRTH DEFECTS (months 2 and 3) -- CV defects and oral clefts