Drugs given IV versus orally, and morphine

[Prince]

Hi

Generally, do drugs that are given intravenously enter breastmilk in a higher concentration than if the drug was given orally because when given intravenously the drug bypasses the barriers of the mother’s GIT to enter the breastmilk more quickly and at higher levels?

However, if morphine is given intravenously then is it in a form that wouldn't be absorbed well orally and hence even more of it reaches the baby through a mother's breastmilk (as compared to morphine given to the mother orally), the baby would get less because it is in a form that is not as highly orally available?

So if the above is true, then if morphine is given to a mother in its oral form, then would more or less reach the baby through her breastmilk as compared to if morphine is given intravenously?

Thank you

[Jimmorison]

you are right

you are right

[Prince]

So, even though the general rule is that more of a drug given IV, as compared to orally, reaches breastmilk, this doesn't necessarily mean that more of it is available to the baby, as many drugs that are given IV are often not absorbed well orally. Right?

So, with the case of morphine, would oral or IV morphine given to a breastfeeding mother have more of an effect on her baby through her breastmilk?

Thanks

[admin]

Prince:

Regardless of the route of delivery to the mom, the amount of morphine in milk is moderate to low. AND the amount in milk must first pass the babies portal circulation and then pass through the liver. 75% of this dose in milk, is sequestered and metabolized in the liver BEFORE absorption into the plasma compartment of the baby. This is why we generally consider morphine an ideal analgesic in breastfeeding mothers...assuming the dose is not too high.

That said, 75% of a super high dose, is still high. So moms that receive very high doses of morphine, or moms that abuse drugs and use high doses of heroin, produce a higher absorption in the infant and greater risk to the infant.



Tom Hale Ph.D.

[Prince]

Thank you.

[narvo]

Yes in my point of view it is right"even though the general rule is that more of a drug given IV, as compared to orally, reaches breastmilk, this doesn't necessarily mean that more of it is available to the baby, as many drugs that are given IV are often not absorbed well orally."