Adverse drug reactions

Last month's research roundup provided you with an overview of articles looking at prescribing in a homeless population (Robertson, 2023). This month, we will be reviewing articles looking at adverse drug reactions (ADRs). The first article looks at the relationship between multimorbidity, polypharmacy, and ADRs in a major teaching hospital in England. The second article looks at a student-run medication review scheme targeting ADRs, while the final paper reviews ADR reporting and prescribing trends in drugs for attention deficit hyperactivity disorder.

This piece of original research published in July 2022 aimed to elucidate the burden and associated cost of ADRs, polypharmacy and multimorbidity with a prospective analysis of all medical admissions over a one-month period but they do not state the month or year this was conducted (Osanlou et al, 2022). The admissions were to a large university teaching hospital in the Northwest of England and one of the criteria was longer than a 24-hour hospital stay. All patients who were admitted from the medical assessment unit were included in the data collection. Information was reviewed to determine if an ADR had occurred and notes, community drug prescriptions and investigations were all included. The main outcome measures the researchers sought to address were the prevalence of admissions due to ADR and the related mortality. Where an ADR was identified as a cause of admission, a contributor to admission or as incidental, each case was assessed to determine the classification of the ADR, the causality, the severity, any interactions and if it was avoidable. All assessments were made using validated assessment tools. In total, over the one-month period, 1187 admissions were scrutinised, and 218 patients were found to have one or more ADRs with 235 ADRs identified in total. This was 18.4% of the admitted population. Of those detected, over 90% were deemed to be causative of admission with 45 categorised as definite, 79 as probable and 94 as possible. Additionally, 86 were or possibly were avoidable with 64 probably caused by a drug-drug interaction. There were significantly more categorised as Type A ADR as opposed to Type B, but the review concluded that four ADRs resulted in death whilst a further five were implicated or contributory to death. The researchers listed the drugs implicated in the ADRs and among them were many commonly used drugs including diuretics, inhalers, antihypertensives and opiates as well as medications used in mental health. Within the ADR group, the mean number of medications patients were taking was 10.5 as opposed to 7.8 in the non-ADR group and they had significantly more co-morbidities. Length of stay in hospital was also reviewed with the ADR group having a mean length of stay of 6 days with an associated increased cost to the trust. The authors conclude that their local prevalence was higher than in previous studies and that the factors of multimorbidity and polypharmacy could be playing a role in this. They, therefore, suggest that by reducing inappropriate polypharmacy may have a knock-on effect in preventing the increasing rate of ADRs and that future efforts should be directed at reducing the burden and therefore the associated financial cost.