Patients with rheumatic diseases across Africa, Southeast Asia, the Americas and Europe had trouble filling their prescriptions of hydroxychloroquine, during the 2020 global coronavirus pandemic, when antimalarials were touted as a possible Covid-19 treatment, says a new study.

Antimalarial drugs are taken regularly by most people with lupus, as well as many with rheumatoid arthritis (RA) and other rheumatic diseases.

In the early weeks of the global pandemic, two antimalarial drugs often used to treat lupus and RA, hydroxychloroquine and chloroquine, were touted to potentially prevent or treat Covid-19 infections despite a lack of data to support this use, leading to worldwide shortages of both.

A team of international researchers launched this study to assess the effects of antimalarials on Covid-19 infection and the impact of drug shortages on people with rheumatic disease.

"Since hydroxychloroquine is an essential treatment for RA and lupus, reported drug shortages of antimalarials became a major concern," said the study's lead author, Emily Sirotich, a doctoral student at McMaster Centre for Transfusion Research in Hamilton, Ontario, Canada.

"The aims of this study were to assess the prevalence and impact of drug shortages during the Covid-19 pandemic, and whether the use of antimalarials in patients with rheumatic disease was associated with a lower risk of Covid-19 infection."

Patients who could not access their antimalarial drugs faced worse physical and mental health outcomes as a result, according to the research presented at ACR Convergence, the American College of Rheumatology's annual meeting being held online from Nov 5-9.

Data for the new study was collected using the Covid-19 Global Rheumatology Alliance Patient Experience Survey which was launched in April.

Of the 9,393 people who responded to the survey, 3,872 were taking antimalarial drugs and 230 said they were unable to continue taking their medications because of a lack of supply at their pharmacy.

Antimalarial shortages were worse for people in Africa and Southeast Asia: 26.7 per cent of respondents in Africa and 21.4 per cent of respondents in Southeast Asia reported inadequate supplies at local pharmacies.

Patients in the Americas (6.8 per cent) and Europe (2.1 per cent) also reported being unable to fill their prescriptions at their pharmacy due to lack of supply.

The study found that patients on antimalarials and those who did not take these drugs had similar rates of Covid-19 infection.

A total of 28 patients with Covid-19, who were also taking antimalarials, were hospitalised.

Of 519 patients diagnosed with COVID-19 in the survey, 68 reported that they were prescribed an antimalarial for their coronavirus infection.

Patients who could not fill their antimalarial prescriptions experienced higher levels of disease activity and also experienced worse mental and physical health symptoms, the study found.