Disadvantages of Ritonavir Boosted Regimens
May be higher risk of dose-related toxicities (e.g., nephrolithiasis with indinavir) of target drug
Risk of additive PI toxicities (esp. GI, lipids, liver)
Wide-ranging interactions with other classes of drugs (e.g., antidepressants, psychotropics, lipid-lowering)
PI levels can still be decreased by inducers if ritonavir dosage is not high enough