From the San Jose Mercury News:
Pfizer Cuts Supplies to 2 Canadian Dealers
Pfizer Inc. cut off supplies to two Canadian drug wholesalers on Thursday, firing a new salvo in the escalating battle between Americans seeking low-cost drugs and the pharmaceutical industry.

It is the first time a drugmaker has choked the supply to wholesalers, although Pfizer as well as other pharmaceutical companies have stopped selling medicines to various Canadian Internet pharmacies.