Adverse drug effects commonly occur in patients with rheumatologic diseases, most of whom take multiple medications to control their primary disease as well as for specific symptoms and comorbidities.The extent to which such effects stem from primary disease-modifying drugs versus other medications has not been well studied.In this large case-control analysis, adverse drug effects occurred more often from ancillary medications than from primary disease-modifying drugs.

Adverse drug effects among patients under treatment for autoimmune rheumatologic disorders stemmed more often from ancillary medications -- and not necessarily prescription products -- than from disease-modifying anti-rheumatic drugs (DMARDs), a large case-control study found.

Some of the strongest sources of adverse drug effects were antibiotics, over-the-counter painkillers, and antacids, with odds ratios reaching into double digits, according to Titilola Falasinnu, PhD, of Stanford University in California, and colleagues.

But the adverse-effects burden wasn't the same across rheumatologic disease categories, the group reported in a medRxiv preprint manuscript.

Patients with systemic sclerosis and systemic lupus erythematosus (SLE) appeared to suffer most from such effects, while those with rheumatoid arthritis (RA) and Sjögren's disease had the fewest problems.