Drugs used in Lactation

Question 1

FACTORS THAT AFFECT THE TRANSFER OF MEDICATIONS INTO
HUMAN MILK
- Milk

Answer 1

 plasma ratio (amount excreted in the milk)
 Dependent on timing of dose relative to breastfeeding
 Varies with changes in milk volume, pH, and content of fat and protein

Question 2

FACTORS THAT AFFECT THE TRANSFER OF MEDICATIONS INTO
HUMAN MILK
- relative infant dose

Answer 2

Relative infant dose
 percentage of maternal dose (mg/kg) received by infant in 24 hour period
relative infant dose < 10% considered safe; more clinically useful
Bioavailability (mother and infant)

Question 3

FACTORS THAT AFFECT THE TRANSFER OF MEDICATIONS INTO
HUMAN MILK
- maternal factors

Answer 3

 Drug dosage and duration of therapy
 Route and frequency of administration
 Metabolism and renal clearance
 Blood flow to the breasts
 Milk pH and composition

Question 4

FACTORS THAT AFFECT THE TRANSFER OF MEDICATIONS INTO

HUMAN MILK - infant phamacokinetic factors

Answer 4

Infant pharmacokinetic factors
 Age of infant
 hepatic capacity in neonate is 10-25% of adult
Lower protein concentration means less bound drug
Lower renal excretion in the first few weeks of life
Lower percent of body fat
 Feeding pattern and amount consumed

Question 5

infant pharmacokinetic factors

Answer 5

 Age of infant
 hepatic capacity in neonate is 10-25% of adult
Lower protein concentration means less bound drug
Lower renal excretion in the first few weeks of life
Lower percent of body fat
 Feeding pattern and amount consumed

Question 6

Drug characteristics (Those most likely to be transferred from
maternal plasma to milk)

Answer 6

Nonionized
Nonprotein bound
Low molecular weight
 High lipid solubility
 High pH

Question 7

Dopamine agonit -examples

Answer 7

metoclopramide

doperidone

Question 8

domperidone

Answer 8

 off-label use to improve milk supply
 development of fatal cardiac arrhythmias
 FDA advises against use

Question 9

Metoclopramide

Answer 9

 used off-label to augment milk supply or induce lactation

 potential CNS effects

Question 10

Dopamine antagonist

Answer 10

 Cabergoline

 off-label use to inhibit lactation

Question 11

Nasal decongestant Pseudoephedrine

Answer 11

 Inhibits milk production

Question 12

Estrogen

Answer 12

Inhibits milk production

Question 13

GUIDELINES FOR PRESCRIPTION DURING LACTATION - avoid

Answer 13

Avoid medications when possible

Question 14

GUIDELINES FOR PRESCRIPTION DURING LACTATION use medicaitons with a realiatve

Answer 14

Use medications with a relative infant dose < 10 percent (found in published
guides on medication use during lactation)

Question 15

GUIDELINES FOR PRESCRIPTION DURING LACTATION - use medicaitons with a short

Answer 15

Use medications with a short half-life, high protein binding, low oral
biovailability, and high molecular weight

Question 16

GUIDELINES FOR PRESCRIPTION DURING LACTATION avoid drus with a

Answer 16

Avoid drugs with a long half-life

Question 17

GUIDELINES FOR PRESCRIPTION DURING LACTATION if a drug has a

Answer 17

If a drug has a short half-life, give it after nursing or before a prolonged
period of infant sleep.

Question 18

GUIDELINES FOR PRESCRIPTION DURING LACTATION use caution with

Answer 18

Use caution with low birth-weight or preterm infants because of potentially
immature organ systems

Question 19

GUIDELINES FOR PRESCRIPTION DURING LACTATION monitor

Answer 19

Monitor the infant

Question 20

GUIDELINES FOR PRESCRIPTION DURING LACTATION discuss

Answer 20

Discuss risks and benefits with the patient as informed consent issue

Question 21

GENERALLY CONTRAINDICATED MEDICATIONS

Answer 21

Immunosuppressive and cytotoxic agents
Drugs with high relative infant dose and/or long half-life
Gold salts
Lithium
Ergotamine
Amiodarone
Retinoids
Long term Tetracyclines
Others: ASA, acebutolol, bromocriptine, phenindione, primidone, sulfasalazine.
Lamitrogine (anticonvulsant), nefazodone (Serzone, antidepressant)

Question 22

DRUGS DEEMED SAFE DURING LACTATION - antibiotics

Answer 22

Penicillins, cephalosporins, macrolides, aminoglycosides

Question 23

DRUGS DEEMED SAFE DURING LACTATION - psychotroipic

Answer 23

 SSRIs (citalopram,escitalopram, sertraline, fluvoxamine, fluoxetine, paroxetine)
 Bupropion (Wellbutrin) (no quantifiable levels in infants after breast feeding; not as well studies).
 Venlafaxine (Effexor) (passes more readily into infant serum, no noted adverse effects)
 Tricyclic antidepressants (excreted into breast milk in low concentrations, no adverse infant effects except

Question 24

DRUGS DEEMED SAFE DURING LACTATION - anticoagulants

Answer 24

 Unfractionated heparin and warfarin
 Fondaparinux
 Danaparoid
 Low molecular weight heparins
 Aspirin

Question 25

DRUGS DEEMED SAFE DURING LACTATION anticonvulants

Answer 25

carbamazepine, ehtosuximide, phenytoin, and valproic acid (some side effects, but
generally considered safe
 Ethosuximide (infant side effects, monitor infant serum levels)
 Gabapentin (limited studies, but promising)

Question 26

DRUGS DEEMED SAFE DURING LACTATION - antihypertensives

Answer 26

Beta-blockers (propranolol, metoprolol, labetalol OK, not acebutlol or atenolol)
 calcium channel blockers (diltiazem, nifedipine, verapamil)
 ACE inhibitors (use caution in the first few weeks of life, enalapril and captopril OK later)

Question 27

DRUGS DEEMED SAFE DURING LACTATION - antihistamines

Answer 27

 loratadine (Claritin) OK
 first generation diphenhydramine and chlorpheniramine have been used without significant
reactions.

Question 28

DRUGS DEEMED SAFE FOR USE DURING LACTATION - nasal

Answer 28

Nasal decongestants: pseudoephedrine may decrease milk supply, chronic use
not recommended

Question 29

DRUGS DEEMED SAFE FOR USE DURING LACTATION contracepton

Answer 29

 Progestin-only recommended (commencement at 6 wks post partum if exclusively
breast feeding versus 3 weeks of supplementing with formula).
 Combined estrogen-progestin (recommendations vary, data mixed, has been shown
to decrease milk supply).
 Levonorgestrel releasing IUD at 6 weeks postpartum OK

Question 30

OTHER DRUG RECOMMENDATIONS

- analgesics

Answer 30

 Acetaminophen, ibuprofen OK
 Longer acting NSAIDs (naproxen) caution advised. ASA not generally recommended.
 Narcotics OK (caution with meperidine); infants should be monitored carefully
 Anesthesia:
 mother should breastfeed immediately before surgery
 may resume when mother is awake and alert
 anesthesia should be informed of lactation and effort madeto use: short-acting benzodiazepines, propofol, muscle relaxants,
inhalation agents and local anesthetics; long-acting medications should be avoided

Question 31

OTHER DRUG RECOMMENDATIONS - social substances

Answer 31

 Caffeine (moderate intake 200-300mg/d OK), alcohol (decreases milk production
 Alcohol
 Generally not recommended
 Single drink cleared within 2-3 hours
 Tobacco not recommended for other reasons
 Substance abuse:
 Generally not recommended
 Methadone is compatible with breastfeeding