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Drugs to avoid

In the name of better patient care - 2024 update

Determined through reliable, rigorous, independent analysis 


Drugs to avoid: a reliable, rigorous, independent analysis

Drugs to avoid What is the purpose of this annual review? What data sources and methodology do we use to assess a drug's harm-benefit balance?

This is Prescrire’s twelfth consecutive annual review of drugs to avoid. It identifies drugs that are more dangerous than beneficial, along with supporting references. The aim is to make it easier to choose high-quality treatments, and to avoid harming patients or exposing them to disproportionate risks. The drugs listed (sometimes only a particular form or dose strength) should be avoided in all the clinical situations for which they are authorised in France or in the European Union.

105 authorised drugs that are more dangerous than beneficial

Drugs to avoid As of early 2024, 105 of the drugs examined by Prescrire between 2010 and 2023 that are authorised in France or in the European Union are more dangerous than beneficial in all their authorised indications. They are listed, based first on the therapeutic area in which they are used, and then in alphabetical order according to their international nonproprietary names (INNs).

These 105 drugs comprise:

  • Active substances with adverse effects that, given the clinical situations in which they are used, are disproportionate to the benefits they provide;
  • Older drugs that have been superseded by newer drugs with a better harm-benefit balance;
  • Recent drugs that have a less favourable harm-benefit balance than existing options;
  • Drugs that have no proven efficacy beyond that of a placebo, but that carry a risk of particularly severe adverse effects.

For each drug, we give the main reasons why it is considered to have an unfavourable harm-benefit balance, together with one or more Prescrire references where subscribers will find further details and the external references on which our analysis was based. When available, better options are briefly mentioned, as are situations (serious or non-serious) in which there is no suitable treatment.

Gaspard BilanThe differences between this year's and last year's versions are detailed > HERE.

What data sources and methodology do we use to assess a drug's harm-benefit balance?

MethodologyOur 2024 review of drugs to avoid is based on the drugs and indications analysed in detail in our French edition between 2010 and 2023. Some were examined for the first time, while others were re-evaluated as new data on efficacy or adverse effects have become available.

One of the main objectives of our publications is to provide health professionals (and thereby their patients) with the clear, independent, reliable and up-to-date information they need, free from conflicts of interest and commercial or corporate pressure.

Prescrire is structured in such a way as to guarantee the quality of the information provided to our subscribers. The Editorial Staff comprise a broad range of health professionals working in various sectors and free from conflicts of interest. We also call on an extensive network of external reviewers (specialists in the relevant area, methodologists, and practitioners representative of our readership), and each article undergoes multiple quality controls and cross-checking at each step of the editorial process.

Gaspard Bilan About Prescrire: How we work > HERE

Our editorial process is a collective one, as symbolised by the “©Prescrire” byline. Prescrire is also fiercely independent. We are funded entirely by our subscribers, carry no paid advertising, receive no grants or subsidies of any kind, and have no shareholders. No company, professional organisation, insurance system, government agency or health authority has any financial (or other) influence whatsoever over the content of our publications.

Gaspard BilanAbout Prescrire: Financing > HERE

Comparison with standard treatments

A drug's harm-benefit balance and the choice of treatment options must be continually re-evaluated as new data on efficacy or adverse effects and new treatments become available. Some drugs are useful in certain situations, offering advantages over other available treatment options, while other drugs are more dangerous than beneficial and should never be used.

Prescrire's assessments of drugs and indications are based on a systematic and reproducible literature search, and collective analysis of the resulting data by our Editorial Staff, using an established procedure:

  •  Efficacy data are prioritised so that most weight is given to studies providing robust supporting evidence, i.e. double-blind, randomised controlled trials;
  • The drug is compared with the standard treatment (not necessarily a drug) when one exists, after careful determination of the best comparator;
  • The results analysed are those based on the clinical endpoints most relevant to the patients concerned, rather than surrogate endpoints, such as laboratory markers, that have not been shown to correlate with improvements in patients' quality of life.

Careful analysis of adverse effects

ImpasseA drug's adverse effects can be more difficult to analyse, as they are often less thoroughly documented than its efficacy. This discrepancy must be taken into account when determining the drug's harm-benefit balance.

The adverse effect profile of each drug is assessed by examining various safety signals that have emerged during clinical trials and animal pharmacotoxicology studies, and by considering its pharmacological affiliation.

When a new drug is approved, many uncertainties remain. Some rare but serious adverse effects may have been overlooked during clinical trials and may only emerge after several years of routine use by a greater number of patients.

 Empirical data and personal experience: risk of major bias

Empirical assessment of a drug's harm-benefit balance, based on individual experience, can help to guide further research, but it is subject to major bias that strongly reduces the level of evidence of the findings. For example, it can be difficult to attribute a specific outcome to a particular drug, as other factors must be taken into account, including the natural history of the disease, the placebo effect, the effect of another treatment the patient may not have mentioned, or a change in diet or lifestyle. Similarly, a doctor who sees an improvement in certain patients cannot know how many other patients' conditions worsened when they received the same treatment.

The best way to minimise subjective bias caused by non-comparative evaluations obtained by simply observing a small number of patients is to prioritise experimental data obtained in patients who agreed to participate in clinical trials, especially double-blind, randomised trials versus standard care.

Serious conditions with no effective treatment: patients should be informed of the consequences of interventions

When faced with a serious condition for which there is no effective treatment, some patients opt to forgo treatment while others are willing to try any drug if it offers the slightest chance of even temporary relief, despite a risk of serious adverse effects.

But patients in this situation must not be treated as guinea pigs. “Trials” of drugs belong in the sphere of formal, properly-conducted clinical research, not health care. It is of course useful to enrol patients in clinical trials, provided they are aware of the known or foreseeable harms and the uncertain nature of the possible benefits. And the results of these trials must be published in detail (whether positive, negative or inconclusive) in order to advance medical knowledge.

However, patients must always be made aware that they have the option of refusing to participate in a clinical trial or of refusing a "last-chance" treatment with an uncertain harm-benefit balance.They must be reassured that these are genuine options, and that if they do refuse, they will not be abandoned but will continue to receive the best available care. Even though support, attention and symptomatic treatments are not intended to cure or slow progression of the underlying disease, they are useful elements of patient care.

While a great deal of uncertainty surrounds the harm-benefit balance of drugs that are undergoing evaluation in clinical trials, drugs used for routine care must have a favourable harm-benefit balance. It is in the common interest that drugs should only be granted marketing authorisation on the basis of proven efficacy relative to standard care, along with an adverse effect profile that is acceptable in the situation concerned, because in general, little if any additional information on efficacy is collected once marketing authorisation has been granted.

Drugs to avoid  > OPEN ACCESS  "Towards better patient care: drugs to avoid in 2024" Prescrire Int 2024; 33 (256): 50-1 - 50-11.

For more about this year's update:

  • Drugs to avoid in the name of better patient care: 2024 update > HERE

  • Drugs to avoid: main changes in the 2024 update > HERE
©Prescrire 1 February 2024

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