This document discusses prescribing medications to lactating mothers. It begins by explaining the mechanisms by which drugs pass into breast milk, including lipid solubility, plasma concentration, protein binding, molecular weight, and pH. Basic drugs are more likely to be secreted in breast milk due to ion trapping. Drugs that should be avoided include basic drugs like morphine and oral contraceptives, acidic drugs available as salts like sulfonamides and ampicillin, non-electrolytes like ethanol, lithium, and drugs that can cause hemolysis in G6PD deficient individuals. In conclusion, drugs administered to nursing mothers can be secreted in quantities significant for the breastfed infant, and it is important for pediatricians to consider

1. PRESCRIBING TO LACTATING
MOTHER
Dr. Pravin Prasad
M.B.B.S., MD Clinical Pharmacology
Lecturer, Lumbini Medical College
17 July, 2018 (1 Shrawan, 2075),
Tuesday

2. BY THE END OF THIS CLASS,
MBBS SEM IV STUDENTS WILL
BE ABLE TO:
Explain the
mechanism of
excretion of drugs in
breast milk
List the drugs to be
avoided in
breastfeeding mother

3. BEFORE WE BEGIN…
What is your understanding about…
o Ion trapping
 Increasing the ion trapping of a
particular drug
 Clinical implication of this phenomenon
o pH of:
 Plasma/blood
 Breast milk

4. HUMAN BREAST MILK
Secreted by
epithelial cells of
alveoli
Components reach
to milk by several
mechanisms
o Exocytosis,
passive diffusion,
transcytosis,
paracellular

5. DRUGS THAT PASSES TO
BREAST MILK
Lipid soluble
Attain high concentration in maternal
plasma
Are low in protein binding
Are in low molecular weight (<800 Da)
Basic drugs

6. BREAST MILK AND ION
TRAPPING
LipidMembrane
For weak acidic drug:
Plasma (pH 7.5)
A- + H+ A- + H+
AH
Breast milk (pH 6.6
AH

7. BREAST MILK AND ION
TRAPPING
LipidMembrane
For weak basic drug:
Plasma (pH 7.5)
H+ +
B
B + H+
BH+
Drug
concentrated in
breast milk
Breast milk (pH 6.6
BH+

8. DRUGS TO BE AVOIDED DURING
BREAST FEEDING
Basic Drugs:
o Hydrochlorides and sulfates forming
drugs
 Morphine
 Bromocriptine
 Oral contraceptives
 Antihistamines
 Anti-depressants

9. DRUGS TO BE AVOIDED DURING
BREAST FEEDING
Acidic Drugs:
o Available as sodium or potassium salts
Drugs Adverse effect on
infant
Sulfonamide Kernicterus, allergy
Ampicillin Diarrhoea
Dapsone Haemolytic anaemia

10. DRUGS TO BE AVOIDED DURING
BREAST FEEDING
Non-electrolytes:
o Ethanol
Low molecular weight electrolytes:
o Lithium
Drugs known to cause hemolysis in G-6-
PD deficient individuals:
o Anti-malarials: quinine, primaquine
o Sulfa drugs: Dapsone, isoniazid

11. CONCLUSION
Drugs administered to nursing mother
can be secreted in quantities significant
for the breastfed infant
Various factors influence the level of
drugs secreted in breast milk
Basic drugs are secreted more in breast
milk
An infant who is being breastfed if visits
you in pediatric OPD, it is essential to ask
the drug history of the mother as well

12. QUESTIONS??
Thank you!!!