Possible thiabendazole-induced theophylline toxicity.

Strongyloidiasis in immunosuppressed patients often requires prolonged administration of the antihelminthic, thiabendazole. The case described herein represents the first report of theophylline toxicity induced by concurrent administration of thiabendazole. Preliminary studies suggest that interference with theophylline clearance by thiabendazole may be the mechanism involved in this drug interaction.