Long term safety of methotrexate in routine clinical care: discontinuation is unusual and rarely the result of laboratory abnormalities.

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Ann Rheum Dis. 2005 Feb;64(2):207-11. Epub 2004 Jun 18.

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Long term safety of methotrexate in routine clinical care:

discontinuation is unusual and rarely the result of laboratory

abnormalities.

Yazici Y, Sokka T, Kautiainen H, Swearingen C, Kulman I, Pincus T.

Brooklyn Heights Arthritis Associates, Long Island College Hospital,

Brooklyn, NY, USA. yaziciy@...

OBJECTIVE: To analyse patients with rheumatoid arthritis, treated

with methotrexate in a weekly academic rheumatology clinic over 13

years, for continuation of courses and reasons for discontinuation.

METHODS: All 248 patients with an analysable longitudinal course who

took methotrexate in standard care between 1990 and 2003 were

studied. Continuation of courses was analysed using life tables. All

abnormal and severely abnormal values for aspartate aminotransferase

(AST) >40 U/l, >80 U/l, albumin <35 g/l, <30 g/l, white blood cell

(WBC) count <4.0 x 10(9)/l, <3.0 x 10(9)/l, and platelet count <150 x

10(9)/l, <100 x 10(9)/l, were identified. Responses of the clinician

and subsequent laboratory values were reviewed. RESULTS: Over 1007

person-years, the probability of continuing methotrexate over five

years was 79% (95% confidence interval, 72% to 84%). Severe

laboratory abnormalities occurred in 2.9 per 100 person-years,

specifically 0.9 for AST >80 U/l, 1.1 for albumin <30 g/l, 0.7 for

WBC <3.0 x 10(9)/l, and 0.3 for platelets <100 x 10(9)/l. No severe

laboratory abnormality progressed to further severity or clinical

disease. Permanent discontinuations of methotrexate occurred in 46

patients (19%), 26 (10% of all patients) for adverse effects, 15

(32.6%) for inefficacy; only two discontinuations resulted from

laboratory abnormalities, both of WBC, possibly from other sources.

CONCLUSIONS: Methotrexate was associated with a high rate of

continuation, and few clinically significant laboratory

abnormalities. Discontinuation primarily reflected clinical rather

than laboratory findings. Vigilance for methotrexate toxicity is

required but methotrexate appears among the safest treatments for

rheumatoid arthritis.

PMID: 15208176 [PubMed - indexed for MEDLINE]