Dispensing Doctors' Association (DDA) chairman Dr David Baker said dispensers had expected the DoH to introduce a higher fee scale from April.
In October last year, the fee scale for dispensers was cut by 8.7 per cent for the remaining six months of the financial year, to bring a 4.9 per cent decrease across the whole year.
This was a temporary measure to bring dispensing profits in line with the pay award recommended by the Doctors' and Dentists' Review Body. The DDA and GPC expected that from 1 April 2010 the fee scale would be raised again.
However, a DoH spokeswoman said: 'In November 2009 there was meeting with the DoH, NHS Employers and BMA where it was agreed that the fee scale wouldn't be adjusted until October 2010.'
GPC Wales chairman and lead GPC negotiator on dispensing Dr David Bailey said: 'Our understanding was the October 2010 adjustments are for the uplift of the fee scale, but that the original fee scale would be automatically put back in April 2010.'
Dispensing practices earn around 7p per item, so practices dispensing 3,000 items monthly are losing out by £210 a month, Dr Baker said.
He had 'great faith' that dispensing practices would be reimbursed, but said this was unlikely before October. In the meantime, it was likely some dispensing practices would suffer cash-flow problems that could affect the delivery of services, he said, adding: 'We have a number of smaller practices who are struggling.'
Dr Bailey said: 'There was no part of the agreement that suggests dispensing practices should make an interest free loan to the government of 4 per cent of their fee scale income. It's just not proper.'