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Drugs to avoid

in the name of better patient care - 2022 update

The result of a reliable, rigourous and independent methodology 


Drugs to avoid: a reliable, rigorous and independent methodology

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? Learn more...

This is Prescrire's tenth consecutive annual review of drugs to avoid. It lists drugs that are more dangerous than beneficial, along with supporting references. The aim is to make it easier to choose safe, effective treatments, and to avoid exposing patients to unacceptable harms. 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.

This list only includes drugs that are actually marketed in one of the following 3 countries that represent the majority of subscribers to our French edition: France, Belgium and Switzerland.

105 authorised drugs that are more dangerous than beneficial

Drugs to avoid As of late 2021, 105 of the drugs examined by Prescrire between 2010 and 2021 that are authorised in France or in the European Union have been identified as more dangerous than beneficial in all their authorised indications (89 of these drugs are marketed in France). 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  • Older drugs that have been superseded by newer drugs with a better harm-benefit balance;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.

The main reasons why these drugs are considered to have an unfavourable harm-benefit balance are explained on a case-by-case basis. 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 lists are detailed > HERE.

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

MethodologyOur review of drugs to avoid lists drugs and indications analysed in detail in our French edition over the 12-year period from 2010 through 2021 inclusive. Some drugs and indications 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 pressures. 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 Bilansee > About Prescrire : How we work

Our editorial process is a collective one, as symbolised by the “©Prescrire” by-line. 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 Bilansee > About Prescrire : Financing

Comparison with standard treatments

The harm-benefit balance of a given drug has to be continually re-evaluated as new data on efficacy or adverse effects become available. Similarly, treatment options evolve as new drugs arrive on the market. Some drugs offer a therapeutic advantage, while others are more dangerous than beneficial and should not be used.

Prescrire's assessments of drugs and indications are all based on a systematic and reproducible literature search. The resulting data are then analysed collectively 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

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

The adverse effect profile of each drug is assessed by examining various safety signals that 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 that might bring them even temporary relief, despite a risk of serious adverse effects.

Drugs to avoid  > FREE PDF  "Towards better patient care: drugs to avoid in 2022" Prescrire Int 2022; 31 (234): 50-1 - 50-10.

For more about this year's update:

  • Drugs to avoid in the name of better patient care: 2022 update > HERE

  • Drugs to avoid: main changes in the 2022 update > HERE
©Prescrire 1 February 2022

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