RESUMEN
Background: Chloroquine and hydroxychloroquine (C/HC) received considerable international media attention due to anticipated treatment effect in COVID-19. This led to increased prescriptions threatening to generate product shortages for patients prescribed within approved indications.We evaluated effects of a temporary regulation mandating pharmacies to only dispense C/HC prescribed by physicians with defined specialties. Methods: Data from Region Stockholm, which include 2.4 out of 10 million Sweden's population, were used. Weekly time trends of prescriptions and requisitions of C/HC by prescriber's workplace during January to April 2020 were followed. Results: Numbers of unique individuals with filled prescriptions of chloroquine increased tenfold and of hydroxychloroquine more than threefold from January to March. In the first week of April, filled prescriptions of C/HC dropped. In the later weeks of April, the number of filled prescriptions was back at similar levels as before the SARS-CoV-2 outbreak.During January and February, specialists in rheumatology accounted for 686 out of all 979 prescriptions dispensed (70.1%) of C/HC. In March, a large proportion of prescriptions dispensed were from specialists not usually prescribing C/HC, and rheumatology accounted for 628 out of all 1,639 prescriptions (38.3%). In April, specialists in rheumatology accounted for 386 out of all 641 prescriptions dispensed (60.0%). Conclusion: After an observed increase in prescriptions of C/HC, a temporary regulation was introduced on 2nd April 2020 to reduce prescriptions from specialists not usually prescribing C/HC to avoid shortages for patients within approved indications. Subsequently, dispensed prescriptions decreased from April and remained at pre-COVID-19 levels thereafter.