Astra Zeneca has revised several sections of the summary of product characteristics for Casodex (bicalutamide) tablets. Co-administration of terfenadine, astemizole or cisapride with Casodex is contraindicated. The following has been added to the special warnings and precautions for use section: "Casodex has been shown to inhibit cytochrome P450 (CYP 3A4), as such, caution should be exercised when co-administered with drugs metabolised predominantly by CYP 3A4". A paragraph has been added to the interactions section which refers to the co-administration of Casodex with drugs with a narrow therapeutic index.