Are people who take lots of medications more at risk of side effects?

A new study published in the British Journal of General Practice has found a link between older people taking a combination of different medications and a bigger risk of side effects (known as adverse drug reactions, or ADRs).

This is the first study in GP surgeries following older people over a long period of time. While past studies followed participants for up to three months, this study followed 592 people aged over 70 for six years.

Participants were seen at 15 GP surgeries in Leinster, in Ireland. The researchers looked at the participants’ medical records and asked them to fill in questionnaires.

The aim was to pin down which characteristics put an older person more at risk of an ADR. The researchers categorised the ADRs as mild or moderate. Examples of a mild ADR might be nausea, a headache, or dry mouth; moderate ADRs included confusion, hallucinations, and stomach upsets that resulted in a hospital visit.

Overall, they found that around one in four people had at least one ADR over the six years. Thankfully around nine in ten of them were in the ‘mild’ category.’ Eight people needed to visit the hospital because of the side effects they had.

People taking between five and nine medicines were almost twice as likely to have an adverse reaction, compared to those taking less than five. People on 10 or more medicines were over three times as likely to have an ADR.

There were also differences in ADR rates between biological genders: older women were at least 50 per cent more likely to have an ADR.

They also found that certain types of medications were more likely to be linked with ADRs; they included medicines for heart and circulatory conditions, antibiotics and painkillers.

• If you're worried about starting a new medication, or you're currently experiencing side effects, read our expert tips on how to deal with medication side effects.

What do the researchers say?

The researchers said that GPs should look to "deprescribe" (stop people taking) medications that are not effective or no longer needed as a way to reduce the risk of side effects in older people and that "it's a good idea for older people taking 10 or more long-term medications, in particular, to have a medication review with their doctor or pharmacist regularly."

They also suggest that GPs should be especially carefully to look out for side effects when they start people on a new drug or change their doses, since adverse reactions can sometimes be mistaken for symptoms of illness. 

The BHF verdict

If you are experiencing any new symptoms, don’t suddenly stop taking your medication, as this could be harmful. Be sure to discuss any changes with your GP or pharmacist first. They will be able to help you understand if the symptoms are side effects, or something else, and advise you on any changes you need to make to your medication, or (in the case of a pharmacist) tell you if you should see your GP.

• Get tips on living with more than one health condition.

How good was the research?

Unlike previous studies, this one had a long follow-up time of six years, and so gives a broader picture of the relationship between older people taking multiple medications and experiencing side effects.

Another strength of the study is that it considered other factors that could contribute to increased risk of an ADR and considered them when looking at the results. Even after accounting for a person's frailty, for instance, there was still a link between number of medications taken and likelihood of an adverse reaction.

As the researchers themselves note, one limit of this study was who was included: only a relatively small number of people in a particular region of Ireland. With ADR rates known to vary from country to country, this makes it harder to draw wider conclusions.

How good was the media coverage?

This research was covered in news outlets such as The Guardian, The Daily Mail and The Independent.

The Guardian article offered an accurate take on the study, covering how the research was conducted and its key findings. Helpfully, it also included a comment from study co-author Professor Emma Wallace: "as we age, we are more likely to live with several long-term health conditions that require multiple medications. It's a good idea for older people taking 10 or more long-term medicines, in particular, to have a medication review with their doctor or pharmacist regularly."

The Daily Mail article, in comparison, left out important study details at the top of the article. The headline reads: "women are most at risk of suffering adverse reactions to drugs, research reveals". The bullet point beneath goes onto claim that "one in four people on long-term medication have one adverse drug reaction”.

Because the article doesn't mention the study age group at the top, it could mislead under 70s into thinking the findings apply to them as well. The Independent headline also oversimplified things, stating “women and patients on more medicines 'at higher risk of adverse drug reaction'".

More worryingly, The Daily Mail article says: “Researchers suggested stopping ineffective medications as a way of minimising the risks.” Actually, the researchers suggested "deprescribing" ineffective medications as a way of minimising risks. There’s an important difference. While the study wording suggests that it should be up to GPs to deprescribe (stop patients taking) medications, the Daily Mail wording might wrongly give the impression that people should stop medications they found ineffective, perhaps without checking with their GP first.

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