Leflunomide in active rheumatoid arthritis: a prospective study in daily practice.
OBJECTIVE
We prospectively studied the efficacy, incidence of adverse drug reactions and withdrawal from leflunomide in an outpatient population with rheumatoid arthritis in a setting of care-as-usual.


METHODS
In this prospective case series study, from outpatient medical records a standard dataset was collected including patient and disease characteristics, data on leflunomide use and adverse drug reactions.


RESULTS
During the study period 136 rheumatoid arthritis patients started leflunomide. Median (range) follow-up duration was 317 (11-911) days. Sixty-five percent of patients experienced at least one adverse drug reaction related to leflunomide. During follow-up 76 patients (56%) withdrew from leflunomide treatment, mainly because of adverse drug reactions (29%) or lack of efficacy (13%). The overall incidence density for withdrawal from leflunomide was 56.2 per 100 patient-years. Complete data for calculating efficacy using a validated disease activity score on 28 joints (DAS(28)) was available for 48, 36, and 35% of patients at 2, 6, and 12 months follow-up, respectively. Within a 12-month period after start of leflunomide treatment 76% of the evaluable patients were classified as moderate or good responders according to the DAS(28) response criteria.


CONCLUSIONS
In the setting of care-as-usual, rheumatoid arthritis patients starting leflunomide frequently experienced adverse drug reactions. More than half of the patients withdrew from leflunomide treatment within a year after start of leflunomide treatment, mainly because of adverse drug reactions.
Van Roon
E N
EN
Department of Hospital Pharmacy and Clinical Pharmacology, Medical Centre Leeuwarden, Leeuwarden, The Netherlands. e.n.van.roon@znb.nl
Jansen
T L Th A
TL
Mourad
L
L
Houtman
P M
PM
Bruyn
G A W
GA
Griep
E N
EN
Wilffert
B
B
Tobi
H
H
Brouwers
J R B J
JR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007555:Isoxazoles / Q000009:adverse effects / Q000627:therapeutic use*; D000077339:Leflunomide; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
D000894:Anti-Inflammatory Agents, Non-Steroidal; D018501:Antirheumatic Agents; D007555:Isoxazoles; D000077339:Leflunomide