Therefore, REYATAZ with ritonavir is contraindicated with medicinal products that are substrates of CYP3A4 and have a narrow therapeutic index: astemizole, terfenadine, cisapride, pimozide, quinidine, bepridil, triazolam, orally administered midazolam, and ergot alkaloids, particularly ergotamine and dihydroergotamine (see section 4.3).