title: Practical perspectives on the use of tipranavir in combination with other medications: lessons learned from pharmacokinetic studies.
abstract: Drug-drug interactions are a major practical concern for physicians treating human immunodeficiency virus (HIV) because of the many medications that HIV-positive patients must take. Pharmacokinetic drug interactions can occur at different levels (absorption, distribution, metabolism, excretion) and are difficult to predict. Of all the processes that give rise to drug interactions, metabolism by cytochrome P450 (CYP3A) is the most frequent. Moreover, medications prescribed to HIV-positive patients may also be CYP3A inhibitors and inducers: Tipranavir, in the absence of ritonavir, is a CYP3A inducer, and ritonavir is a CYP3A inhibitor. Fortunately, the drug interactions between tipranavir coadministered with ritonavir and other antiretroviral medications or with other medications commonly used in HIV therapy are well characterized. This review summarizes the pharmacokinetic interactions between tipranavir/ritonavir and 11 other antiretroviral medications and between tipranavir/ritonavir and drugs used to treat opportunistic infections such as fungal infections, antiretroviral-treatment-related conditions such as hyperlipidemia, and side effects such as diarrhea.
authors.affiliation: PK Research, St. Stephen's Centre-Chelsea and Westminster Hospital, 369 Fulham Road, London, SW10 9NH, United Kingdom.
authors.forename: Marta
authors.initials: M
authors.lastname: Boffito
authors.forename: Desmond
authors.initials: D
authors.lastname: Maitland
authors.forename: Anton
authors.initials: A
authors.lastname: Pozniak
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000188:drug therapy; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D019380:Anti-HIV Agents / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D004347:Drug Interactions; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D011725:Pyridines / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D011753:Pyrones / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D013449:Sulfonamides
chemical_list: D000900:Anti-Bacterial Agents; D019380:Anti-HIV Agents; D011725:Pyridines; D011753:Pyrones; D013449:Sulfonamides; C107201:tipranavir