Key takeaways
Nelfinavir (Viracept) and tipranavir (Aptivus) are both protease inhibitors used to treat HIV. They work by blocking a protein that helps the HIV virus make copies of itself. Both medications are taken orally and are available by prescription. However, there are several differences between them. Nelfinavir is available in tablet and oral powder forms, while tipranavir comes in capsules and an oral solution. Nelfinavir is typically taken two to three times a day with food, whereas tipranavir must be taken twice daily with a booster called ritonavir (Norvir). Both medications can cause diarrhea and nausea. You may not be able to take either one if you have liver problems, and both medications have a number of drug interactions. Tipranavir is not recommended if you have a sulfa allergy.
