Adverse drug reactions: a huge burden on healthcare systems

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Adverse drug reactions: a huge burden on healthcare systems

Rheumawire

Jul 7, 2004

Nainggolan

Liverpool, UK - Adverse drug reactions (ADRs) are an important cause of

hospital admissions, accounting for 1 in 16 hospital admissions and

costing the UK National Health Service (NHS) almost half a billion

pounds a year, according to the largest prospective analysis ever

conducted there.

This finding is similar to pooled data from several studies worldwide,

which found that around 5% of hospital admissions result from adverse

drug reactions, say Dr Munir Pirmohamed (University of Liverpool, UK)

and colleagues in their paper in the July 3, 2004 issue of BMJ [1].

However, many of these studies are more than 20 years old, " and it is

disappointing that the burden of ADRs has not decreased " in the

intervening years, say Pirmohamed et al.

The drugs most likely to cause adverse reactions were older agents such

as aspirin (low-dose), warfarin, diuretics, and nonsteroidal

anti-inflammatory drugs (NSAIDs). Gastrointestinal bleeding was the most

common reaction.

Pirmohamed and colleagues from the department of pharmacology and

therapeutics at University of Liverpool assessed 18 820 patients aged

older than 16 years who were admitted to 2 NHS hospitals in the region

over a 6-month period. Drug history and symptoms were used to determine

whether the admission had been caused by an ADR.

A total of 1225 admissions were related to an adverse drug reaction,

giving a prevalence of 6.5%. The average stay was 8 days, which

accounted for 4% of the hospital bed capacity. The projected annual cost

to the NHS of such admissions was £466m.

" Extrapolating this to the whole NHS bed base in England suggests that

at any time the equivalent of up to seven 800-bed hospitals may be

occupied by patients admitted with ADRs, " the researchers state.

Although most patients recovered, 28 (2.3%) died as a direct result of

the adverse reaction. Deaths were due to gastrointestinal bleeding (15),

intracranial hemorrhage (5), renal failure (5), perforated duodenal

ulcer (2), and lithium toxicity (1).

Although aspirin was identified as a causal agent in 18% of all

admissions for ADRs, " the finding that low-dose aspirin was the most

common drug implicated is relatively novel, " Pirmohamed et al say.

However, they note that caution needs to be exercised when interpreting

these data.

First, " we do not have consumption data for these drugs, and the rank

order of implicated drugs may be a reflection of how commonly they are

used. " Second, " we have concentrated on harms and have not taken into

account the benefits of the drugs. This may be particularly true for

drugs such as low-dose aspirin, for which convincing data exist of the

long-term benefits of prophylactic use in high-risk patients. "

Nevertheless, measures that can further improve the benefit/harm ratio

and avoid some of these ADRs " need to be put in place, " the researchers

say. " Our data would suggest that over 70% of the ADRs in this study

were either possibly or definitely avoidable. "

" It is therefore incumbent on prescribers to determine the need for a

particular drug in a patient and to use this drug at the lowest dose

necessary to achieve benefit, " they note. Other methods include

prescribing, for example, proton pump inhibitors or misoprostol as a

cost-effective method of reducing gastrointestinal side effects

associated with NSAIDs, they conclude.

Source

Pirmohamed M, S, Meakin S, et al. Adverse drug

reactions as cause of admission to hospital: prospective analysis of 18

820 patients. BMJ 2004; 329:15-19

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org