`Rising tide’ of drug prescriptions needs to addressed, says new study

A ‘rising tide’ in the use of prescribed medications and potentially serious drug interactions raises significant concerns of adverse drug reactions that need to be addressed, according to a new study published by researchers at the University of Dundee.

A fifteen-year study of prescribing data for all 310,000 adults resident in the Tayside region of Scotland showed that, between 1995 and 2010, the proportion of adults being dispensed more than five drugs doubled to 20.8 per cent, and the proportion dispensed more than 10 drugs tripled to 5.8 per cent.

Researchers say this rise in multiple drug use increases worries of potentially serious clashes arising from drug interactions. The results of their study have been published in the journal BMC Medicine.

“Prescribed drugs significantly improve a range of health outcomes, but they can also cause considerable harm – approximately 6.5 per cent of all emergency hospital admissions are attributable to adverse drug events and at least half of these are judged preventable,” said Professor Bruce Guthrie, of the University of Dundee, who led the study.

“Our study shows there has been a significant rise in the numbers of people receiving multiple drugs. This raises concerns because the simultaneous use of large numbers of drugs, what we call polypharmacy, can cause serious harm in some patients.

“More research is needed to better understand the impact on people’s health of multiple interacting drugs.”

The study found that elderly people were much more likely to be prescribed more than ten drugs, but also found it was more common among people living in more deprived areas and in people resident in a care home.

In 1995, one in seventeen adults were prescribed drugs with potentially serious interactions, and this more than doubled to one in eight adults by 2010.  The number of drugs prescribed was the characteristic most strongly associated with this. Since older people were prescribed more drugs, 44% of those aged 70 years and over were prescribed drugs with potentially serious interactions in 2010.

“Drug regimens are increasingly complex and potentially harmful, and people with

polypharmacy need regular review and prescribing optimisation,” said Professor Guthrie.

Recent research, again carried out by a team led by Professor Guthrie, showed that blindly following recommendations for drug prescriptions in national clinical guidelines for conditions including diabetes, depression and heart failure will often result in potentially serious drug interactions.

They found that potentially serious clashes between drugs prescribed for different conditions were `common’



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Roddy Isles
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