Oral methotrexate: hazard of different tablet strengths

L. D. Hordon, P. Le Gallez and A. H. Isdale1

Department of Rheumatology, Dewsbury & District Hospital, Halifax Road, Dewsbury, West Yorkshire WF13 4HS and
1 Department of Rheumatology, Friarage Hospital, East Road, Northallerton DL6 1JG, UK

Correspondence to: L. D. Hordon

SIR, We applaud the efforts of Schott et al. [1] to persuade the manufacturers to alter the appearance of the two different strengths of methotrexate. Since our case report of a similar mishap with methotrexate in 1994 [2], Dewsbury drug information sheets all carry the following information:

WARNING Methotrexate is prescribed in two doses, 2.5 mg and 10 mg. BOTH ARE SMALL YELLOW TABLETS. Always check your bottle carefully when collecting a new prescription. Make sure they are 2.5 mg tablets. If not, ask the Pharmacist to change them.

Northallerton drug information sheets also carry a similar warning. In addition, patients are given this information verbally along with all other necessary information on starting methotrexate.

However, this policy did not prevent a potentially serious error by a 15-yr-old English born Asian girl with juvenile chronic arthritis on methotrexate for 5 yr, who also took 40 mg of methotrexate instead of 10 mg. She was too worried to report her mistake, which she recognized immediately, and her family, who did not read English, remained unaware that it had happened. Fortunately, she came to no harm.

A change in the appearance of the two strengths of methotrexate is long overdue.

References

  1.  Schott JM, Rigby SP, McNally JD, Keat A, Higgens CS. Oral methotrexate: the hazard of different tablet strengths. Rheumatology 1999;38:382.[Free Full Text]
  2.  Isdale AH, Hordon LD, Daly M. Methotrexate mishap. Br J Rheumatol 1994;33:503–4.
Accepted 21 June 1999