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Polypharmacy

Background, Goal and Objectives Polypharmacy PDF
Polypharmacy - weighing up the benefits and harms
Elderly people are at increased risk of drug related problems
Drugs associated with increased risk of adverse drug reactions in elderly people
Common drug interactions in elderly people
Recognising adverse drug reactions
Risk factors for drug related problems in elderly people
A really good recipe for DRP
Drug related harm; terms and definitions
Hospital admissions for adverse drug reactions
Commonly reported adverse drug reactions
References, Bibliography

Polypharmacy - weighing up the benefits and harms

The use of multiple drugs is accepted best practice for common chronic conditions such as hypertension and diabetes. Conscientious clinicians, who adhere to evidence-based guidelines, will often find themselves prescribing six or more drugs for people with several chronic conditions. However, trials investigate populations and clinicians treat individuals.

Many people on five or more drugs will be taking an unfamiliar or even unique combination (Bjerrum, 1998). The potential benefits and risks of harm of such regimens will not have been subject to research and are often difficult to predict. The difficulty is balancing the potential benefits of these drugs, as described in the guidelines, with the risk of harm from the high number of drugs used. Clinicians need to consider carefully numbers needed to treat, numbers needed to harm, long term prognosis and the wishes of individual patients.

Polypharmacy
Potential benefits Risk of harm
Synergistic combinations allow lower doses and therefore less adverse effects than individual drugs.
e.g. treatment of hypertension
Synergistic adverse effects increase risk of harm.
e.g. may increase risk of falls due to postural hypotension
Supplemental drug may decrease adverse effect of initial drug.
e.g. anticholinergic added for drug induced extrapyramidal effects
Increased complexity of the regimen can lead to confusion, error and poor adherence.
e.g. multiple tablets, multiple doses, increased risk of side effects
Additional drug may improve outcomes.
e.g. addition of spironolactone to ACE inhibitor for heart failure
Increased opportunities for drug interactions.
e.g. increased risk of hyperkalaemia
Multiple drugs may be needed for multiple conditions.
e.g. diabetes plus osteoarthritis
More drugs = more opportunity for adverse effects. Difficult to predict interactions within a complex regimen.
e.g. ACE inhibitor plus NSAID increases the risk of renal failure

  “First do no harm”
Hippocrates, 460-355 BC
Many people on five or more drugs will be taking an unfamiliar or even unique combination (Bjerrum, 1998). The potential benefits and risks of harm of such regimens will not have been subject to research and are often difficult to predict.
Figure 1. Risk of harm increases with number of drugs taken
The risk of an adverse drug event has been estimated at 13% for two drugs, 58% for five drugs and 82% for seven or more (Fulton & Allen, 2005).
Risk of event

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