Whoever takes drugs is sick and expects recovery. Most of us know about adverse effects, they are well researched and documented in clinical studies, but hardly anyone expects serious problems or even death. Physicians and patients rely on the proven effectiveness and security. But how high the percentage of deaths actually is, is not quite clear and subsequently hard to detect. The pharmacologist Anna Jönsson at the University in Linköping/Sweden and her colleagues found out in a cohort study based on publication, that adverse effects of pharmaceuticals are the seventh most frequent cause of death in Sweden. Results were published in the British Journal of Medical Pharmocology.
More than 5% of all referrals to hospitals due to adverse effects
It is nothing new that adverse effects do not only lead to visits at the doctor, but also to referrals to the hospital. As early as 2004, the Merseyside-study made on 18,820 patients and published in the British Medical Journal showed that 6.5% of all hospital referrals were connected with unwanted adverse effects of drugs, with 80% of them leading straight to the referral to the hospital. However, the death rate was only at 0.15%, which seems rather low considering the latest Swedish figures. Since the Swedish researchers estimate the death rate of hospital patients caused by adverse effects at about 5%.
According to Jönsson, it is rather difficult to ascertain the overall mortality rate because in most cases, the death certificate is the only document to refer to but adverse effects hardly ever appear on them. That is why the scientists analyzed every seventh case of death occurring in three different regions in Sweden in 2001. The patients’ record gave evidence for suspicious cases, which a clinical pharmacologist and a forensic pathologist checked afterwards.
3% of the death cases due to fatal adverse drug reactions
In 49 (3.1%) of 1,574 cases of death the scientists suspected a fatal side effect of drugs (fatal adverse drug reaction, FADR). Originally almost two thirds of the cases were caused by hemorrhages. Gastro-intestinal hemorrhages most frequently lead to death (37%), followed by brain hemorrhages (29%), cardiovascular diseases (10%), other hemorrhages (8%) and renal dysfunction (6%). The drugs causing the most frequent death rate were antithrombotics (63%), non-steroidal antiphlogistics (NSAID; 18%), antidepressants (14%) and cardiovascular drugs (8%). 41 cases (6.4%) of a total of 639 deaths happening in the hospital, the researchers traced back to a fatal adverse effect of a drug.
Not taking any drugs is no solution either
The results do not imperatively mean that all examined patients who died due to an adverse drug reaction would still be alive if they would have not taken those pharmaceuticals. This view only shows one side of the coin, says Simon Thomas, physician at the University of Newcastle in the UK. Frequently used drugs causing hemorrhages as for example anti-thrombotics or NSAID have great advantages and are indispensable for many patients. The fatal adverse effects have to be opposed to the number of patients where drugs have a life-prolonging effect and to those having a better quality of life due to the NSAID.
The risk of fatal adverse drug reaction is often underestimated and the medical burden is high, as Jönnson and her colleagues assume considering the figures.
However, they did not practice aetiology. They now want to comb through the case reports again to find out which death cases could have been avoided. Current literature makes us surmise that this could be 18% to 70%.