Kobelt said he’s seen boxes of Bayer AG (BAYN)’s Aspirin in Poland that originated in Greece, suggesting that the medicine fetches higher prices in eastern Europe.

“Even Polish people pay more than Greeks for Aspirin,” he said. “That is the recipe for parallel trade, I’m sorry to say.”

Novo Nordisk A/S (NOVOB), based in Bagsvaerd, Denmark, is a case in point.

“We are competing with our own products,” said Mike Rulis, a spokesman for the company.

Novo stopped selling some of its higher-priced insulins in Greece for about a month in 2010 after the government cut prices by about 25 percent. The drugmaker now ships in the same volume as before the cuts, yet pharmacists are running short of insulin, Rulis said in a telephone interview.