Tipranavir significantly lowers doses of saquinavir, amprenavir and lopinavir/r
Simon Collins, HIV i-Base
Interaction data were presented again from the BI 1182.51 study using tipranavir with additional protease inhibitors in extensively PI-experienced patients. 
Although management of treatment-experienced patients has often included multiple-PI and boosted-PI regimens, the negative interaction of tipranavir in reducing levels of saquinavir, amprenavir and lopinavir/r must be remembered.
HTB reported this data in full when it was presented at the pharmacology workshop earlier this year, and no new data was added to the analysis in Bangkok. 
Tipranavir is available in the UK on an expanded access programme.
- Walmsley S, Leith J, Katlama C et al. Pharmacokinetics and safety of tipranavir/ritonavir (TPV/r) alone or in combination with saquinavir (SQV), amprenavir (APV), or lopinavir (LPV): interim analysis of BI1182.51. XV Intl AIDS Conference, Bangkok. Abstract WeOrB1236.
- See HTB Vol 5 No 4, May 2004.