Pregnancy and Lactation Flashcards

1
Q

Counseling tips for lactating women include

A

Eat a balanced diet
Take prenatal vitamins (do not take if not specified for pregnant women!)
Intake should be no more than 0-1 cups of coffee, tea, or caffeinated beverage daily
Avoid raw meat (listeria) or fish with high mercury levels
Eat plenty of fruits and veggies, wash before eating!

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2
Q

What pharmacokinetics change with pregnancy (specifics)

A
  • Maternal plasma volume increases
  • Cardiac output increases
  • Glomerular filtration increases (drug excretion decreases)
  • Body fat increases (VoD increases)
  • Plasma albumin decreases (VoD increases; unbound drugs cleared faster)
  • Hepatic perfusion increases
  • Delayed gastric emptying (N/V)
  • Gastric pH increases
  • Estrogen and progesterone increase
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3
Q

Overall, PK changes in pregnancy lead to

A

Increased volume of distribution
**Increased clearance
decreased protein binding
shorten or lengthen elimination half life

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4
Q

What factors affect movement of drug from maternal to fetal circulation

A
Lipophilicity 
protein binding 
molecular weight 
drug pKa 
placental CYP450
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5
Q

Highly lipophilic drugs…

A

more easily cross the placental barrier to enter fetal circulation

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6
Q

What conditions must be present to allow hydrophilic drugs (like lithium) to cross the placental barrier

A

Protein binding low enough

Molecular weight low enough

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7
Q

Highly protein bound drugs have a

A

lower free fraction available to diffuse into fetal circulation (AKA less crosses over)
-UNLESS you keep levels of the drug high enough, in which it may cross over solely due to the amount of drug present

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8
Q

How do least and most maternally protein bound drugs differ

A

Least protein bound reach higher concentrations in fetus than highly protein bound drugs

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9
Q

If a drug is more highly bound in the fetus rather than maternal, it will concentrate on

A

the fetal side

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10
Q

What happens to albumin in mom and baby

A

Lowers in mom but increases in baby!

But as pregnancy progresses, the ratio may change despite consistent maternal dosing

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11
Q

How does molecular weight affect drug movement

A
Low molecular weights (<500 Da) easily cross the placenta 
Larger molecules (600-1000 Da) cross more slowly 
>1000 Da do NOT cross the placental barrier
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12
Q

How do fetal and maternal pH compare

A

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

So, some degree of ion trapping can concentrate drugs on the fetal side

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13
Q

What is pKa

A

a measure of acid strength

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14
Q

What were we made aware that the fetal CYP450 system does

A

Placenta converts prednisolone to the INactive prednisone

So, prednisolone can be used in pregnant patients without the risk of fetal exposure to an active corticosteroid!

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15
Q

Can anesthesia and analgesia drugs be used in pregnancy?

A

Not usually; they cross the placental barrier well and fetal effects can be noted at birth (respiratory depression 2/2 mom on narcotics)

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16
Q

Why do we get baby out ASAP after C-Section

A

because mom is given analgesics and anesthetics! We dont want to harm baby

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17
Q

Fetal CYP450 appears when

A

as early as 14 weeks, and increases throughout pregnancy

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18
Q

Glucuronidation is immature until

A

near or after birth

So, fetus can metabolize drugs that cross the placenta, and toxic agents can be found in the fetus

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19
Q

These anti-HTN are believed to be safe during pregnancy

A
CCB, Nifedipine
Beta blockers 
Methyldopa 
Hydralazine 
CCB 
Magnesium Sulfate (IV infusion as inpatient)
20
Q

These anti-HTN are contraindicated in pregnancy

A

ACE
ARB
-can both lead to fetal renal failure

21
Q

These antibiotics are safe in pregnancy

A

Nitrofurantoin (macrobid, macrodantin)

Penicillins, cephalosporins

22
Q

These antibiotics are NOT safe in pregnancy

A

Sulfonamides (displace bilirubin from albumin and enhance kernicterus

23
Q

These antiemetics are safe in pregnancy

A

Promethazine (phenergan)
Ondansetron (zofran) if unrefractory
Vitamin B6!

24
Q

A side effect of antiemetics in pregnancy are

A

Phenergan: anticholinergic, acute dystonia, akathisia
Zofran: headache

25
Q

Bromocriptine previously was used in pregnancy to

A
Suppress lactation (TRH stimulates PRL secretion; Dopamine activates D2 to stop PRL)
No longer recommended 2/2 reports of stroke, MI, Sz, and HTN in postpartum women
26
Q

Bromocriptine is an

A

ergot derivative that activates D2 receptors and inhibits prolactin release= stop lactating!

27
Q

Resources to check for drugs used in pregnancy include

A

Lactmed

motherisk.org

28
Q

How do drugs move into breast milk

A

passive diffusion and carrier mediated transporters (similar to organic cation transporters found in liver and gut)

29
Q

Explain different milk:plasma drug concentrations

A
>1: drug is concentrated in breast milk 
MC: 1 or less 
25%: >1
15%: >2 
BUT: ratio reported is meaningless
30
Q

If the ratio doesnt matter, what DOES matter?

A

how much total drug is ingested and absorbed by the baby
-Total amount of a drug in a day’s volume of breast milk is usually small compared to an oral therapeutic dose for the infant

31
Q

What exposure is used as a conservative cutoff for concern

A

Index value of no more than 10% of a therapeutic dose for infants
EXCEPT: drugs that cause hemolysis in infants with G6P deficiency, and chemotherapeutic drugs

32
Q

Use caution with these drugs in breastfeeding women

A
Codeine 
Ciprofloxacin 
Doxycycline
Fluoxetine 
Diphenhydramine 
Lithium 
-Lisinopril, Cyclophosphamide, Valporic acid
33
Q

Absolutely avoid these drugs in pregnant women

A
Oxycodone 
Meperidine 
Methotrexate 
Lithium 
Phenobarbital 
Primidone (metabolized to phernobarb) 
Ethosuxamide
Chemotherapeutic drugs 
Amiodarone 
Atenolol 
Nadolol
Cocaine 
Iodine (betadine)
34
Q

Instead of oxycodone and meperidine, use

A
  • Use low dose morphine instead, or methadone

- intermittent LOW doses of oxycodone are considered safe

35
Q

What BB can be used in breast feeding

A

Propranolol and labetalol

36
Q

Can you use sedatives or hypnotics in breast feeding women

A

Intermittent use is fine, prolonged use has allegedly been shown to cause withdrawal symptoms in infant

37
Q

How can you treat BV in pregnancy

A

Metronidazole

OR 2: clindamycin

38
Q

How can you treat chlamydia in pregnancy

A

Azithromycin

OR: amoxicillin, erythromycin

39
Q

How can you treat herpes in pregnant women

A

Acyclovir, started at 36 weeks gestation

40
Q

How can you treat gonorrhea in pregnancy

A

Ceftriaxine (IM) PLUS Azithromycin

41
Q

How can you treat syphilis in pregnancy

A

Primary, secondary, tertiary: Benzathine penicillin

Neurosyph: Aqueous penicillin G

42
Q

How can you treat Trichomoniasis in pregnancy

A

Metronidazole

43
Q

How can you treat allergic rhinitis in pregnancy

A

Intranasal corticosteroids (Budesonide)
Intranasal Cromolyn
First gen antihistamines (benadryl)

44
Q

How can you treat asthma in pregnancy

A

Albuterol alone if intermittent

Albuterol + ICS (Budesonide) and LABA if persistent

45
Q

How can you treat epilepsy in pregnancy

A

Safest AED: carbamazepine, lamotrigine, levetiracetam, phenytoin, gabapentin, henobarbital, topiramate, VPA
polytherapy has higher risk of malformations than monotherapy

46
Q

How can you treat HIV in pregnancy

A
If currently on ART: continue regimen if viral load is suppressed 
Dual NRTI 
Ritonavir 
NNRTI 
Integrase inhibitor
47
Q

How can you treat thyroid disorders in pregnancy

A
  • Hyper: PTU (first trimester), Methamizole (after first trimester)
  • Hypo: Levothyroxine