Given their health system's heavy reliance on imported pharmaceuticals, medicines have been one of the main concerns of many Greeks as they face an uncertain period in which dealing with foreign suppliers has become more complicated.

Sunday's decision to impose capital controls, blocking transfers out of Greece after a flood of withdrawals, had been expected for days and there were few signs of outright panic when it was confirmed.

But it did not take long for the measures to start choking up the normal flow of operations for many businesses, among them the pharmacists.

Along with petrol stations, pharmacists shops are one of the most sensitive intersection points between consumers and the global economy from which Greece has been set partially adrift by capital controls. Greece is heavily reliant on imports of pharmaceuticals and oil.

When Galani called suppliers on Monday morning, she was told that she would not be able to increase orders beyond their previous levels to guard against stockpiling.

"The suppliers have started imposing quotas on the size of orders we can make today, so they don't run out of medicines if pharmacy owners decide to stock up," Galani told Reuters.

Greece's SFEE pharmaceuticals association, which represents local companies as well as subsidiaries of multinationals, said it would seek to keep an adequate supply of medicines flowing through the system.

Other industry sources say there have been problems with a small number of suppliers, although most foreign drug makers have said they would continue to ship to Greece, despite unpaid a mounting total of bills running at more than 1 billion euros.

But, with payment systems gummed up, the problems are less a matter of outright shortage than of bottlenecks and restrictions because of worries over getting paid.

Even before the government slapped capital controls on the banks to stop the system collapsing, stocks of certain imported drugs had grown scarce because suppliers were not getting paid by the strained public health system. The situation is expected to worsen sharply as stocks run down.

"In a few days there will be lots of problems. The pharmacies are only accepting cash and since they can't pay their suppliers, it's going to create problems," said 42-year-old doctor Ioannis Mavromatis. He said he normally accepts credit cards from clients but was having to accept cash only.

(Writing by James Mackenzie; editing by Janet McBride)

By Lefteris Karagiannopoulos

Stocks treated in this article : Sanofi, Pfizer Inc., Novartis AG, Red Sky Energy Limited