- The following medications are expressly prohibited during the course of the trial: Astemizole, cisapride, ergot derivatives, hydroxyurea, midazolam, thalidomide, triazolam, vincristine, zalcitabine, ribavirin, doxorubicin, Voriconazole, St. John's wort or any medications that are contraindicated for concomitant use as described in the current product information packet insert for the ARV therapies used.