Under the changes that started this week, medication will now only be reviewed by a pharmacist every two years instead of every 12 months. The rationing of services also applies to elderly people receiving care at home, and has drawn the ire of aged care providers and advocates.

But the Pharmacy Guild of Australia and the federal Health Department said the program of reviewing medication management that has been running for 17 years was no longer financially sustainable due to a cost blowout driven by the ageing population and suspected rorting by service providers.

''The simple fact is that the government has made clear there is no more money for these medication management programs and that we must work within the existing … budgets,'' Pharmacy Guild national president George Tambassis said.

Aged care advocates say the cutback may cost the public even more money as it puts elderly people at greater risk of suffering adverse reactions to their medication.

Australian research shows that adverse drug reactions account for one-third of hospital admissions in people aged 75 and over.

The Society of Hospital Pharmacists of Australia said the move would undermine the care of Australia's 226,000 nursing home residents. ''SHPA believes it is unacceptable to reduce access to services that improve medication use and that have been shown to improve patient care and reduce admission to hospital,'' it said. ''Reducing access will result in adverse outcomes for patients.''

Lynda Saltarelli, head of lobby group Aged Care Crisis, said older people were at high risk of ''poly-pharmacy'' due to the number of different drugs they use.

''The majority of aged care residents have a combination of complex medical conditions and may need to take multiple medications, taking seven to eight medications on average,'' she said.

''This 'poly-pharmacy', in turn, greatly amplifies the risk of medication errors. Aged Care Crisis is already concerned about reports of many elderly residents inappropriately medicated with antipsychotic medications, for example, together with the absence of safe staffing ratios in aged care, recklessly reducing their level of protection.''

Industry body Leading Age Services Australia has asked the Health Department and the Pharmacy Guild for an undertaking that ''no older Australian will be denied a medication management service if it is clinically warranted''. It also asked the government for more probity checks to reduce the risk of service providers rorting the system.

A spokesman for Health Minister Peter Dutton said patients would be able to have their medication reviewed under the government-funded program if there were ''significant changes'' to their condition or drug regimen.

He said the changes to the existing programs were made to ensure their ongoing sustainability.