All of the following drugs are protease inhibitors, EXCEPT:: (A) Nelfinavir, (B) Saquinavir, (C) Abacavir, (D) Ritonavir
Answer is C. Abacavir is nucleoside reverse transcriptase inhibitor and not a protease inhibitor. Nelfinovir, Titonavir and Saquinavir are all protease inhibitor. Ref: Antiretroviral Therapy By Erik De Clercq, 2001, Page 147 ; Harrison's Principles of Internal Medicine, Pages 1124, 1126.