Table 2.

Patients with emergent protease mutations on PI monotherapy

No.	PI agent	HIV RNA at start (copies/mL)	Previous PI use	Protease mutations before PI monotherapy	Emergent protease mutations	Outcome of PI monotherapy	Loss of future PI options (level of resistancea)
1	DRV	0	none	none	minor: 10I	VF, but ongoing PI monotherapy (last RNA undetectable)	no
2	DRV	780	LPV	none	minor: 35D/G	VF, but ongoing PI monotherapy (last RNA undetectable)	no
3	DRV	350 000	ATV	none	minor: 11I/V	VF, but ongoing PI monotherapy (last RNA 100 000 copies/mL)	no
4	LPV	420	SQV	none	major: 46I, 84V minor: 10F	VF and switched to cART	ATV, FPV, IDV, NFV, SQV (high) LPV, TPV (intermediate)
5	ATV	1700	ATV	none	major: 50L, 90M minor: 71V, 73S	VF and switched to cART	ATV, NFV, SQV (high) IDV (intermediate)
6	LPV	0	SQV, NFV	minor: 10I, 58E	major: 50L	VF and switched to cART	ATV (high)
7	LPV	360	none	major: 50L, 88S minor: 33F, 71V	major: 82A/V	VF and switched to cART	IDV (intermediate)
8	DRV	0	LPV	major: 46I minor: 10F, 74A/P	major: 32I, 47V	VF and switched to cART	FPV, IDV, LPV, NFV, TPV (high) ATV, DRV (intermediate)
9	ATV then DRV	0	SQV, LPV	missing data	major: 24I, 50L minor: 71T	VF on ATV, switch to DRV ongoing PI monotherapy (last RNA undetectable)	ATV (high)

VF, virological failure; DRV, darunavir; LPV, lopinavir; ATV, atazanavir; SQV, saquinavir; NFV, nelfinavir; FPV, fosamprenavir; IDV, indinavir; TPV, timprenavir.

^aStanford HIV Drug Resistance Database interpretation.