Text: Stéphanie de Roguin

When medicines don't work as planned

In Switzerland, almost 10% of hospital admissions are due to the use of a medication and its potential adverse side effects. Many of these situations could be avoided by taking a few simple steps.

Have you ever felt worse after taking a medication than before? It’s hardly a rare occurrence. In fact, it accounts for almost 10% of hospital admissions in Switzerland, according to the Patient Safety Foundation. Why such a high percentage? How can we avoid these adverse side effects, and how do you reverse the situation once they do occur?

When discomfort or an unexpected skin rash occurs after taking a medication, it would be more accurate to refer to it as an “adverse event,” says Thierry Buclin, physician in chief of the Clinical Pharmacology Division at Lausanne University Hospital (CHUV). “An event is something that is observed. Once the problem is detected, we conduct an investigation to understand whether or not it is related to the medication. If the problem concerns an individual, we follow the steps of clinical diagnosis by process of elimination.
If the problem is more widespread, a series of studies is carried out to determine whether or not there is causality. We then refer to it as an adverse reaction when the cause-and-effect relationship is confirmed.”

Different types of adverse side effects

Medical staff can anticipate these adverse side effects depending on their type. Type A adverse side effects essentially involve the drug’s pharmacological action. These include effects directly linked to a given treatment, such as an anticoagulant administered to relieve thrombosis, which can cause haematomas.

Type B or “off-target” pharmacological effects include reactions triggered by certain antibiotics containing compounds designed to attack bacteria but which can also bind to other structures in the body, e.g. neuroreceptors. In the spring of 2022, the Swiss newspaper Le Temps reported the story of a patient who was being treated for pneumonia with antibiotics and experienced a manic episode with mystical delirium. That is probably an example of a Type B reaction.

Type B adverse events are less frequent and therefore more difficult to predict. An allergy or intolerance to a drug is unpredictable if the patient is in contact with the compound for the first time. In this case, the body triggers an inflammatory reaction to defend itself. This reaction can lead to a series of adverse events such as hepatitis and arterial or cerebral attacks.

Rare events to be taken seriously

It may seem surprising that adverse events occur frequently, considering how long it takes to test and get approval to launch any new medication to market. “Some rare or very rare adverse reactions, interactions with other drugs or other risks associated with the use of a drug only arise after the product is approved and once it’s widely used,” says Lukas Jaggi, spokesperson for Swissmedic. These risks should not be ignored under any circumstances, as they can have fatal consequences. “This margin of error is partly explained by the fact that candidates who take part in clinical trials are generally younger and healthier than

the patients who actually take the drug once it’s on the market,” says CHUV expert Thierry Buclin.
What’s more, patients take several drugs, which means more drug interactions.

The importance of pharmacovigilance

It is crucial for adverse events to be reported, in order to improve information for patients, particularly in the leaflets contained in all medicine packages. Since 2003, any doctor or pharmacist informed of such an event has been required to report the event to the Swiss Pharmacovigilance Network. The CHUV’s Clinical Pharmacology Division is part of this network to answer questions from physicians. The patient’s medical record is carefully analysed to provide individualised recommendations, such as deciding whether to permanently withdraw the drug from the market. The experts then describe the case anonymously in a pharmacovigilance database coordinated by Swissmedic. The data is combined with data from a large number of WHO countries, including the Uppsala Monitoring Centre in Sweden. In Switzerland, around 3,000 reports are filed per year.

“Specialists can therefore identify signs of adverse effects. This could warrant new studies, additional information on package inserts or even contraindications for certain patient profiles,” Thierry Buclin says.
The last resort is to withdraw the drug from the market. That happens several times a year, as several dozen new drugs are launched to market every year.

Advice on taking medicine

A few simple steps can help to avoid some adverse events, says Sébastien Marti, owner and manager of three pharmacies in the canton of Neuchâtel and vice-president of PharmaSuisse. “It may seem obvious, but simply reading a medicine’s package leaflet carefully and following the instructions provided, for example taking the pill with or before a meal, is crucial but often ignored.” Some medicines containing ibuprofen, such as Algifor, can increase stomach acids.
Taking them with a meal reduces irritation. Also, consuming alcohol or tobacco can interfere with the effect of some medications. The package leaflet contains information on this sort of incompatibility.

Similarly, sticking to the prescribed dose is just as important. “If the patient feels the need to change the amount prescribed, because the effect is too strong or not strong enough, they should speak to their GP or pharmacist.” Generally speaking, being transparent with healthcare professionals and giving them as much information as possible prevents lots of problems. Finally, using a pillbox or a weekly calendar can be a useful way of making sure you’ve taken your medication(s).

Thierry Buclin recommends taking as little medication as possible. The expert also mentions the case of regular taking anti-inflammatory drugs. That often increases blood pressure, so antihypertensives are prescribed to control the effect. “We should take all steps to avoid these prescribing cascades.
Sometimes there are benefits to removing a drug instead of adding one,” says Thierry Buclin, physician in chief of the CHUV Clinical Pharmacology Division.

The development of electronic patient records (EPRs) is also likely to offer a promising solution for improving the information available to all the healthcare professionals involved in treatment. The EPR provides access to the history and an overview of the situation for each of their patients. At facilities that already work with internal computerised systems, any drug incompatibility is automatically signalled. /

* not their real names



“We should take all steps to avoid prescribing cascades. Sometimes there are benefits to removing a drug instead of adding one,” says Thierry Buclin, physician in chief of the CHUV Clinical Pharmacology Division.