Abstract: Received: 19 May 2020 Revised: 3 July 2020 Accepted: 8 July 2020 DOI: 10.1111/bcp.14482 ORIGINAL ARTICLE Clinical outcomes and adverse events in patients hospitalised with COVID-19, treated with off-label hydroxychloroquine and azithromycin Mary Kelly1 | Ròisìn O'Connor1,2 | 1 Liam Townsend2,3 1 | 1 Miriam Coghlan1 | 1 Eileen Relihan | Miriam Moriarty | Bernard Carr | Gail Melanophy | Caitriona Doyle2 | Ciaran Bannan2,3 | Ruth O'Riordan2 | Concepta Merry2 | Susie Clarke2 | Colm Bergin2,3 1 Pharmacy Department, St James's Hospital, Dublin, Ireland 2 Aims: To assess clinical outcomes and adverse drug events in patients hospitalised with Department of Genitourinary Medicine and Infectious Disease (GUIDe), Hospital 5 St James's Hospital, Dublin, Ireland COVID-19 treated with off-label hydroxychloroquine (HCQ) and azithromycin (Az). 3 positive polymerase chain reaction test for SARS-CoV-2 and received HCQ plus Az Trinity College Dublin, Ireland Correspondence Ms Mary Kelly, Pharmacy Department St James's Hospital Dublin 8, Ireland. Email: marykellympharm@gmail.com Methods: We performed a retrospective analysis of hospitalised patients who had a or no targeted therapy. The primary end point was clinical improvement on day 7 defined as either hospital discharge or an improvement of 2 points on a 6-category ordinal scale. Secondary outcomes included mortality at day 28, intensive care admission, requirement for mechanical ventilation and incidence of adverse events. Results: Data from a total of 134 patients were evaluated; 82 patients received HCQ/Az and 52 patients received no targeted therapy. Clinical improvement was seen in 26.8% of patients who received HCQ/Az but this was not significant. The rates of intensive care transfer and mechanical ventilation were higher in the treatment group, but these differences were not significant. Mortality at day 28 was significantly higher in the treatment group (P = .03). Hypoglycaemia elevated liver function tests and QT prolongation were monitored in both groups. The risk of QT prolongation was significantly higher in the treatment group. Treatment was stopped early in 6 (7.3%) patients due to adverse events. Conclusion: Although patients who received HCQ/Az were more severely ill the administration of these repurposed drugs did not result in clinical improvement and was associated with a significant increase in toxicity. This descriptive study highlights the importance of monitoring all repurposed agents for adverse events. KEYWORDS adverse drug events, azithromycin, clinical pharmacy, COVID-19, hydroxychloroquine, medication safety The authors confirm that the Principal Investigator (PI) for this paper is Professor Colm Bergin and that he had direct clinical responsibility for patients. The PI confirms that we have complied with our institution's policies concerning research involving human subjects and the NREC policies for protection of human subjects. Br J Clin Pharmacol. 2020;1–5. wileyonlinelibrary.com/journal/bcp © 2020 The British Pharmacological Society 1 2 KELLY ET AL. 1 | I N T RO D UC TI O N Since December 2019, the newly emergent coronavirus (SARS-CoV-2) has caused an ongoing pandemic of COVID-19.1–3 The disease spectrum can range from a mild, uncomplicated illness managed in a community setting to severe disease requiring intensive care support, which may progress to death. In Ireland, as of 8 June 2020, there have been 25 198 cases diagnosed, 1691..