blood dyscrasias and sulphasalazine

Last reviewed 01/2018

Sulphasalazine should be stopped immediately there is suspicion of a blood dyscrasia. It is recommended that full blood counts are performed before treatment and monthly for the first 3 months of therapy.

Blood dyscrasias account for 19% of all reported reactions to sulphasalzine:

  • leukopenia occurs in up to 1.5%
  • agranulocytosis has a peak incidence of 1 in 700 during the second month of therapy

CSM reports:

  • 191 reports of neutropenia, leukopenia or agranulocytosis - 22 fatal
  • 44 reports of bone marrow depression or aplastic anaemia - 13 fatal
  • 30 reports of thrombocytopenia - 1 fatal

Reactions were reported:

  • within 3 months of starting in 14 patient
  • 3-6 months in 6 patients
  • 6-11 months in 2 patients

Reference:

  • Current Problems (1993). CSM, 19, 6
  • Amos RS et al (1986). BMJ, 420-3
  • Keisu M and Ekman E (1992). Eur J.Clin Pharm, 43, 215-218