Toxicity profiles of traditional disease modifying antirheumatic drugs for rheumatoid arthritis

Abstract

Background: The progression of rheumatoid arthritis (RA) can be retarded or halted by disease modifying antirheumatic drugs (DMARDs). Next to inefficacy, toxicity limits their use.

Objective: To explore the toxicity profiles of DMARDs in daily life.

Patients and methods: Five hundred and ninety three patients with RA charts (>2300 patient years of treatment) were reviewed at two rheumatology outpatient clinics. All recorded data on toxicity and reasons for stopping treatment were collected.

Results: Adverse events were common reasons for treatment discontinuation (42% of treatments). In 70% they were subjectively reported at the clinical visit, while substantial laboratory abnormalities were seen relatively rarely (9% of treatments: abnormal liver function tests in 5%; haematological abnormalities in 3%; impaired renal function in 1%). No single case of retinopathy from antimalarial drugs (that is, an incidence of <0.3 events/1000 patient years) was found, although eye examinations by the specialists were abnormal 30 times per 1000 patient years, mostly revealing keratopathy. Most commonly reported symptoms per 1000 patient years were nausea (54 events), abdominal pain (37 events), and rashes (34 events). Adverse events were more likely to occur with increasing number of consecutive DMARD courses.

Conclusion: The first DMARD course in a patient seems to be safer than the consecutive ones. In addition, the incidence of adverse events (AEs) seems to be similar for high and low dose treatment. Data are also provided on types and incidence of AEs that are consistent with previous studies in other countries and different settings.

Figure 1

Major symptoms in patients taking DMARDs (events/1000 patient years).

Figure 2

Ranking of major symptoms in patients treated with various DMARDs. Incidence in events/1000 patient years is given in parentheses).