Adverse drug reactions (ADRs) are unwanted drug effects that have considerable economic as well as clinical costs as they often lead to hospital admission, prolongation of hospital stay and emergency department visits. Randomized controlled trials (RCTs) are the main premarketing methods used to detect and quantify ADRs but these have several limitations, such as limited study sample size and limited heterogeneity due to the exclusion of the frailest patients. In addition, ADRs due to inappropriate medication use occur often in the real world of clinical practice but not in RCTs. Postmarketing drug safety monitoring through pharmacovigilance activities, including mining of spontaneous reporting and carrying out observational prospective cohort or retrospective database studies, allow longer follow-up periods of patients with a much wider range of characteristics, providing valuable means for ADR detection, quantification and where possible reduction, reducing healthcare costs in the process.Overall, pharmacovigilance is aimed at identifying drug safety signals as early as possible, thus minimizing potential clinical and economic consequences of ADRs. The goal of this review is to explore the epidemiology and the costs of ADRs in routine care.

Background: Adverse drug reactions (ADRs) are an important public health problem, representing a major cause of morbidity and mortality. However, several countries have no recent studies available. Since 2014, a prospective active pharmacovigilance project, aimed to improve ADRs monitoring in hospital wards (FORWARD) was performed in Sicily. This study, as part of FORWARD project, was aimed to describe ADRs occurred during the hospital stay in Internal Medicine wards. ADRs related to hospital admission, characteristics and preventability of ADRs were also evaluated.Methods: Demographic, clinical, and pharmacological data on patients admitted to six wards of Internal Medicine, from 2014 to 2015, were collected by trained, qualified monitors, who screened all medical records. The rate of ADRs occurred during hospital stay and those leading to hospitalization were analyzed. A descriptive analysis of the reactions, suspected drugs, and associated factors was performed according to the setting analyzed.Results: During the study period, 4,802 admissions were recorded; in 3.2% of them ADRs occurred during hospital stay while in 6.2%, admission was due to ADRs. The duration of hospital stay was longer in patients who experienced ADRs during hospitalization, compared to patients without ADRs [median days 12 (Q1–Q3: 8–17) vs. 9 (6–13)]; p < 0.001). Females [OR1.39 (95% CI 1.03–1.93)] and patients taking ≥ 4 drugs [OR1.46 (95% CI 1.06–2.03)] were more likely to experience ADRs during hospital stay, as well as to be admitted because of ADRs [female: OR1.75 (95% CI 1.37–2.24); ≥ 4 drugs: OR2.14 (95% CI 1.67–2.74)]. The most frequent ADRs occurred during hospital stay were cutaneous (26.8%), general (13.4%), vascular (13.4%), and cardiac (11.5%) disorders and the drug classes mainly involved were anti-bacterials (38.2%) and antithrombotic agents (21.7%). ADRs were serious in 44.6% and probably preventable in 69.4%. Gastrointestinal (27.7%), hematological (26.5%), metabolic (18.1%), and nervous (16.1%) disorders were the main ADRs cause of hospitalization, primarily due to antithrombotic agents (39.0%) RAS-inhibitors (13.9%), NSAIDs (11.9%), and diuretics (9.0%). Only 12.9% of them was not preventable.Conclusion: Adverse drug reactions occurred during hospitalization or contributing to admission to Internal Medicine wards were considerable and most of them were preventable. Females and patients taking many medications were more likely to present ADRs both during hospital stay or as cause of admission.

The global COVID-19 pandemic has led to a race to find medications that can improve the prognosis of the disease. Azithromycin, in association with hydroxychloroquine or chloroquine, has been proposed as one such medication. The aim of this review is to describe the pharmacological mechanism, clinical evidence and prescribing guidelines concerning azithromycin in COVID-19 patients. There is weak evidence on the antiviral and immunomodulating effects of azithromycin, which in addition is not based on results from COVID-19 patients specifically. Therefore, this antibacterial should be considered only as empirical treatment of community-acquired pneumonia (CAP), although not all current treatment guidelines are in agreement. After the initial expectations raised by a small trial, more recent evidence has raised serious safety concerns on the use of hydroxychloroquine or chloroquine with azithromycin to treat COVID-19 patients, as all these drugs have arrhythmogenic potential. The World Health Organization has not made recommendations suggesting the use of azithromycin with hydroxychloroquine or chloroquine as treatment for COVID-19, but some national organisations have taken a different position, recommending this as first-line treatment. Several scientific societies, including the American College of Cardiology, have cautioned about the risks of this treatment in view of the lack of evidence concerning its benefits.

No abstract

This study validates that spontaneous reporting, despite its limitations, can be an important resource for detecting ADRs associated with the concomitant use of interacting drugs. Moreover, our data confirm that DDIs could be a real problem in clinical practice, showing that more than one in five patients exposed to a potential DDI experienced a related ADR.