The hunt for unwanted effects

Almost 1,480,000 days of hospitalization per year are due to adverse drug reactions. And 48% of them would be preventable. This is what emerges from the last survey carried out in 2007 by the regional pharmacovigilivance centers (CRPV). Under the leadership of the French Health Security Agency (Afssaps), the CRPVs looked at the hospitalizations of 62 medical departments, representative of all public hospitals. “Of the 2,692 patients, 97 cases were attributed to a drug iatrogenic problem, ie an incidence rate of 3.6%,” explains Dr. Françoise Haramburu who coordinated the cross-sectional study (EMIR) and head of the CRPV from Bordeaux. This represents 143,000 hospitalizations per year if we extrapolate this figure to the national level.

“These results are very close to the last study carried out in 1998, where the percentage of hospitalizations was 3.19%”, recalls Jean Marimbert, the director general of Afssaps. According to the survey, the undesirable effects are primarily vascular disorders (20.6% of cases including hemorrhages), neurological disorders (11.3%), and gastrointestinal disorders (9.3% ). Hospitalizations lasted on average just over 10 days. Who are the affected patients? They are old people. The average age of hospitalized patients is 62 years, but when patients are over 75, the incidence rate is 5.5%. “Patients hospitalized for adverse effects are on average ten years older than those hospitalized for another reason,” notes Dr Haramburu. 167 drugs were considered to be the possible cause of the 97 hospitalizations, some by misuse or administration.
“We noted as the case of a 32-year-old woman who was taking 3 benzodiazepines per day, and who decided to stop suddenly, testifies the coordinator of the EMIR survey. The next day, she was hospitalized for convulsions and withdrawal syndrome. This example is one of six self-medication mistakes we found. But we also noted two hospitalizations due to a prescription error. ”

The EMIR study shows that anti-vitamin K (AVK) anticoagulants are responsible for 12% of hospitalizations. Diuretics come in second with an incidence rate of 0.41%. Anticancer drugs have a lower incidence rate (0.33%). Regarding AVK drugs, Afssaps is mobilizing again. These drugs were already the main cause of adverse effects in the 1998 study (13%). “Should we consider that our preventive actions were in vain? “asks Anne Castot, responsible for risk monitoring and information on drugs at Afssaps.
In fact, in 2001 and 2004, Afssaps carried out an information campaign among patients and health professionals. “We must not go too fast in the conclusions. The total number of boxes and doses administered doubled between 1996 and 2007, specifies Anne Castot. And the number of patients treated with antivitamin K rose from 500,000 to 900,000, which represents 1% of the French population ”. In 2008, Afssaps relaunched an information campaign on the proper use of AVKs, particularly among general practitioners. New information documents will be sent to them shortly. In addition, Afssaps wants to strengthen the use of a notebook that allows the patient to monitor the action of AVK on the fluidity of his blood (NIR index). “It was developed in 2004,” explains Bernard Delorme, head of the patient information unit at Afssaps. Currently, it is estimated that 250,000 notebooks are in use. We are going to send new ones which will be distributed by the prescribing doctors ”.

Questions to Anne Castot, responsible for risk monitoring (AFSSAPS)

A study every 5 years

Are the results obtained the same as those of 1998?
Anne Castot. Anti-vitamin K anticoagulants remain the primary sources of undesirable effects. This was the case in 1998. But this year, the results show a new kid on the top 10 drugs responsible for hospitalizations. These are diuretics.

How to explain cela ?
A. C. There are a number of factors to consider. First, the overall aging of the French population. Diuretics are drugs mainly prescribed for older people who have cardiovascular problems. Then, this can also be explained by changes in practices and patient care. We must not forget that we have brought much more powerful drugs to the market.

What steps are you going to take?
AC In particular, we are going to launch a campaign for the proper use of diuretics. More generally, however, we are going to strengthen surveillance by renewing the study on hospitalizations due to adverse drug reactions more frequently. Instead of waiting 10 years, we will renew it within 5 years. In order to follow developments as well as possible.