[lemontea88]

I always thought that if a drug is highly protein bound, it WILL CROSS the placenta?

 

[Graymess]

Placenta/Plasmatic Membrane

Hi, LemonTea.
I'll try to say it as simple as possible, Here's the thing:

Transport through placenta and trough plasma membrane depends on different factors:

Placenta: Blood Flow; Exchange Surface,Gestational Age (as pregnancy goes 2 term it becomes more permeable) and it happens through different mechanisms: Diffusion, Pinocitosis, Etc.

Plasma Membrane transport depends on size of the molecule, charge of the molecule...and here is astatement completely different from yours "Uncharged molecules pass through Plasma Membrane, not otherwise; remember the Negative Charge of Different Plasma Membrane Proteins repel Charged Molecules..."

Phenobarbital is Recommended 4 Prophylaxis and Pregnancy. See the connection? Anyway I hope this could help you but don't stop investigating though, to expand your knowledge and criteria.

Blessings!
GrayMess

 

[lemontea88]

Thx Graymess.

By the way, is there a general rule that says that all lipophilic molecules are protein bounded in the plasma?

 

[Doc-Yuvi]

Thx Graymess.

By the way, is there a general rule that says that all lipophilic molecules are protein bounded in the plasma?

would it be safe to say that since Phenytoin is teratogenic, one is not left with too much choice for effective treatment of simple and grand mal seizures. Not sure, im just shooting in the dark here.