Conclusions
The way in which HCQ has been used during the Covid-19 pandemic has resulted in a change in its safety profile. This change has reflected in the SEFV-H database. Of particular concern, there has been an increase in reporting disproportionality for cardiac arrhythmias, severe hepatotoxicity, severe skin reactions, and suicidal risk. HCQ-related eye disturbances seem to be mostly related to the prolonged use of the drug. In the setting of the clinical HCQ use in Covid patients, we identified the following signals: dyslipidaemias and some severe gastrointestinal conditions, such as ischaemic colitis. On the contrary, the signals identified for HCQ use in no-Covid patients were malignancies and pulmonary interstitial disease. However, these findings should be interpreted with caution, since they would need to be subjected to a detailed analysis of the aggregate cases enabling to formulate firmly based hypotheses. Furthermore, our findings need to be replicated with appropriate observational studies allowing confirming the hypotheses that eventually can be derived from the present study.