Subject: What processes lead to lysis of erythrocytes after Na+ influx is inhibited?

I've asked a question similar to this already, but I am still a litlle confused.

I am testing a drug (Phenamil) on erythrocytes.

It's function is to block the inward movement of  Na+ ions by inhibiting 
epithelial-type Na+ channels, but leaves the  Na+/H+ and Na+/K+ pumps 
unaffected.

The end result observed is a lysis of the cell, but what osmotic events are 
occuring for this to happen??

Please help.... I'm starting to go mad!

David Colwill (Going-mad-scientist)

Re: What processes lead to lysis of erythrocytes after Na+ influx is inhibited?