There are some medicines you cannot take at all with REYATAZ: rifampicin, an antibiotic used to treat tuberculosis, astemizole or terfenadine (commonly used to treat allergy symptoms, these medicines may be available without prescription); cisapride (used to treat gastric reflux, sometimes called heartburn); pimozide (used to treat schizophrenia); quinidine or bepridil (used to correct heart rhythm); ergotamine, dihydroergotamine, ergonovine, methylergonovine (used to treat migraine headaches), medicines containing St.