Study design: In a two-way-cross-over design volunteers received sulphadiazine alone or one hour after an oral dose of guar gum. Drug and metabolite levels were measured up to 24 h to test possible interaction.

Results: No difference in urine levels was observed between the administration regimens.

Conclusions: A 1 h separation interval of orally administrated guar gum, known for its action in glycaemic control,  and sulphadiazine prevents possible absorption interaction between the substances.