Interpretation
Maximum levels of sulphasalazine are reached in 3-5 hours following an oral dose.
The plasma level of unmetabolised sulphasalazine does not correlate with therapy but rather serves to establish compliance, particularly in the presence of a therapeutic level of sulphapyridine, since a patient not complying with the prescribed treatment regimen but taking medication just prior to testing will have a measurable sulphasalazine concentration but a low sulphapyridine concentration.
