Pharmacy leaders have backed criticism of "rigid" 28-day prescribing rules, after a study found the practice could be costing "considerably" more than it is saving.

A more "flexible" approach to prescribing was needed to meet patients' needs and ensure pharmacists were "robustly funded" through medicine optimisation services, PSNC and Pharmacy Voice agreed.

Research published in Primary Health Care Research Development found that, despite the higher volume of prescriptions generated by 28-day prescribing creating "short-term gains" for pharmacies, the time taken to dispense the prescriptions would "ratchet down" profits in the longer term.

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	The study, published on October 4, also found blanket use of the policy cost the NHS £150 million in 2009, which was "considerably more" than any possible savings made.

Researchers, led by professor of pharmaceuticals and public health at UCL School of Pharmacy David Taylor, looked at prescribing trends between 1998 and 2009. They found that of 11 medicines, including aspirin, atorvastatin and simvastatin, the number of doses per prescription had decreased by "approximately seven tablets" in the past decade, following pressure to limit prescriptions to 28 days of medication.

While the "rational" use of 28-day prescribing reduced waste, it did not justify "unselective" use of the policy, they said.

"The supply of medicines should be organised in ways that maximise customer satisfaction and minimise professional workloads, even if longer average prescription durations are, on occasions, associated with an increased risk of physical waste," they said.

"It is possible that a more flexible approach to regulating prescription lengths could increase service efficiency and effectiveness, while also creating a more convenient system for some patients."

Pharmacy Voice, which had previously hit out at 28-day prescribing for having "no clinical logic", told C+D this week that prescription intervals "should support effective use by patients, while minimising the likelihood of medicines being wasted through oversupply".

And PSNC said that, while 28-day prescribing ensured regular contact between pharmacies and patients, more flexibility was needed.

"A system that is flexible enough to work with patients' individual circumstances as part of a structured and robustly funded medicines optimisation service provided by community pharmacies could benefit all parties," said head of NHS services Alastair Buxton.

Earlier this year, patients with long-term conditions also voiced dissatisfaction with the 28-day prescribing system, branding it "tedious".