Understanding polypharmacy, overprescribing and deprescribing

Nina Barnett, Consultant Pharmacist, Medicines Use and Safety (SPS)Published
Topics: Polypharmacy

The process of managing non-beneficial or potentially harmful multiple medicines including reducing or stopping medicines, and explanations of terminology

How we got here

Over the last 30 years, older people have been prescribed increasing number of medicines. The many reasons for this, including:

  • the advent of evidence-based medicine
  • increase in multiple morbidity and longevity
  • promotion of age-independent access to the increasing number of treatments
  • increasing expectations for treatment from patients and their families

The risks

Health professionals have become increasingly concerned about the risks of multiple medicines.

This is because there is evidence associating increased medicines use this with increased:

  • adverse drug events
  • hospital admissions
  • health care costs
  • non-adherence

This is particularly worrying given that medicines are the most common health care intervention.


Polypharmacy refers to the prescribing or taking of too many medicines.

Rather than being associated with a fixed number of medicines e.g. 5 medicines per day, it now relates to prescribing or taking more medicines that are clinically required. This is sometimes known as “appropriate” and “problematic” polypharmacy.

There are number of terms which have come into use to describe multiple medicines use including and hyperpolypharmacy, oligopharmacy and deprescribing.

Appropriate polypharmacy

Appropriate polypharmacy is defined as:

“prescribing for an individual for complex conditions or for multiple conditions in circumstances where medicines use has been optimised and where the medicines are prescribed according to best evidence.”

Problematic polypharmacy

Problematic polypharmacy is defined as:

“the prescribing of multiple [medicines] inappropriately, or where the intended benefit of the [medicines are] not realised.”

This refers to the prescribing of ten or more medicines and the phrase has come into use to distinguish it from polypharmacy, which is increasingly common.

This seeks to promote the deliberate avoidance of polypharmacy.

If considered in terms of numbers of medicines, this is the prescribing of less than 5 prescription medicines daily.

This is the complex process required for the safe and effective cessation (withdrawal) of inappropriate medication.

It is recognised that much of the evidence to support stopping medicines is empirical and based on the patient’s physical functioning, co-morbidities, preferences and lifestyle.


Overprescribing refers to situations where patients are prescribed medicines:

  • that they do not need or want
  • where potential harm outweighs the benefit of the medication
  • when a better alternative is available but not prescribed
  • where the medicine is appropriate for a condition but not the individual patient
  • when a condition changes and the medicine is no longer appropriate or required but is still prescribed

Current evidence

The National Overprescribing Review identified the following key points:

  • 8.4m people in England are regularly prescribed 5 or more medicines
  • 1 in 5 hospital admissions in over-65s are caused by the adverse effects of medicines
  • the more medicines a person takes, the higher chance there is that one or more of these medicines will have an unwanted or harmful effect.

There are both clinical and financial consequences to overprescribing: 10 percent of the volume of prescription items dispensed through primary care in England are inappropriate for that patients’ circumstances and wishes, and they could be better served with alternative treatments.

New concepts

Non-pharmacological alternatives to prescribing is a concept promoted by the National Overprescribing Review.

The review also promotes embedding deprescribing in the prescribing process, supports the NHS net zero agenda and contributes to reducing medicines waste.

Highlights of the review

The National Overprescribing Review identifies the need for effective wider medicines optimisation strategies as well as for individuals; making detailed recommendations about the system, culture and implementation.

These include expanding the use of structured medication review in primary care to target groups at risk of overprescribing, with recommendations applicable in all patient care settings.

The patient centred polypharmacy process can be used as a framework for undertaking structured medication review.

Further information