Low dose pulse oral methotrexate (MTX) is a well established treatment
for rheumatoid arthritis, and short term open studies have suggested
beneficial effects of MTX in SLE. This study was designed to investiga
te MTX treatment maintenance rates in SLE using life table analysis, a
nd to determine whether MTX use was associated with a dose reduction o
f concomitant steroid therapy. All SLE patients managed by physicians
affiliated with a single centre were studied cross-sectionally. Inform
ation regarding disease variables and drug use were ascertained by int
erview and chart review. Drug therapy data including dates of treatmen
t and indications for treatment were analysed using Kaplan-Keier life
table methods. Among 101 subjects with SLE, 25 MTX treatment episodes
were observed in 24 subjects. The period studied totalled 19 766 patie
nt-days, with a median (range) duration of observed MTX treatment of 1
4.4 (5.1-41.6) months. The median (range) initial and peak MTX doses w
ith 7.5 (2.5-10)mg/wk and 10 (7.5-15)mg/week respectively. The princip
al indication for commencing methotrexate therapy was arthritis. Only
two subjects terminated treatment for toxicity, with the most common r
eason for termination being remission. The cumulative probability of c
ontinuing treatment was 68% at 12 months and 61% at 24 months, or 75%
and 71% respectively if cessations for remission were excluded. The me
dian (interquartile range) monthly steroid intake during MTX therapy [
279.4 (193.4-492.9)mg] was somewhat lower than during the 6 months pri
or to [298.1 (237.9-531.4)428.8) mg] MTX therapy, but this difference
was not significant. A total of 36% of subjects reduced their steroid
dose during MTX therapy, but this reduction was not significant. Treat
ment of SLE with MTX, predominantly for arthritis, was well tolerated
over prolonged periods of observation. Toxicity of sufficient severity
to lead to treatment termination was uncommon. A subset of subjects w
ere able to reduce steroid intake during MTX therapy, but no overall r
eduction in steroid dose was observed.