Table 2.
Factors influencing lopinavir plasma concentration
| Change in drug concentration (% change in ng/mL) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|
| univariable |
multivariable 1 |
multivariable 2 |
|||||||
| Parameter | effect | 95% CI | P | effect | 95% CI | P | effect | 95% CI | P |
| Age (per 10 years) | 2.8 | −6.1 to 12.5 | 0.55 | 2.0 | −6.8 to 11.6 | 0.67 | 3.4 | −5.7 to 13.3 | 0.48 |
| Gender (female versus male) | 17.0 | −3.0 to 41.2 | 0.10 | 15.9 | −8.1 to 46.1 | 0.21 | 19.0 | −6.4 to 51.2 | 0.16 |
| Ethnicity (black versus white) | 0.8 | −14.6 to 19.0 | 0.93 | −10.7 | −26.8 to 9.1 | 0.27 | −12.2 | −28.6 to 8.0 | 0.22 |
| Weight (per 10 kg) | −13.2 | −18.3 to −7.8 | <0.001 | −10.7 | −16.1 to −5.0 | <0.001 | −10.5 | −15.9 to −4.7 | 0.001 |
| Time on LPV (per 4 weeks) | 0.1 | −0.4 to 0.6 | 0.74 | −0.1 | −0.6 to 0.5 | 0.85 | −0.1 | −0.7 to 0.5 | 0.76 |
| Time on current regimen (per 4 weeks) | 0.2 | −0.6 to 0.9 | 0.62 | 0.4 | −0.5 to 1.3 | 0.38 | 0.5 | −0.4 to 1.5 | 0.26 |
| LPV dose (533 versus 400 mg/r) | 17.0 | −0.9 to 38.3 | 0.06 | 22.2 | 4.2 to 43.4 | 0.014 | 24.8 | 2.9 to 51.3 | 0.024 |
| On rifabutin (yes versus no) | 119.3 | 44.1 to 233.8 | <0.001 | 108.6 | 37.2 to 217.2 | 0.001 | 116.0 | 41.0 to 231.1 | <0.001 |
| On zidovudine (yes versus no) | 9.8 | −9.5 to 33.2 | 0.34 | 6.1 | −15.2 to 32.8 | 0.60 | |||
| On lamivudine (yes versus no) | 5.2 | −9.9 to 22.8 | 0.52 | 13.4 | −4.7 to 35.0 | 0.16 | |||
| On stavudine (yes versus no) | −8.2 | −29.9 to 20.2 | 0.53 | 0.8 | −23.5 to 32.7 | 0.96 | |||
| On tenofovir DF (yes versus no) | −4.8 | −18.5 to 11.1 | 0.53 | 8.3 | −8.7 to 28.3 | 0.36 | |||
| On didanosine (yes versus no) | 3.8 | −12.7 to 23.3 | 0.67 | 7.9 | −10.0 to 29.4 | 0.41 | |||
| On abacavir (yes versus no) | −6.6 | −22.9 to 13.2 | 0.49 | −11.0 | −26.3 to 7.5 | 0.22 | |||
| On efavirenz (yes versus no) | −2.3 | −20.5 to 20.2 | 0.83 | −10.5 | −28.5 to 11.9 | 0.33 | |||
| On nevirapine (yes versus no) | 22.7 | −3.6 to 56.1 | 0.10 | 8.0 | −17.0 to 40.5 | 0.57 | |||
| On saquinavir (yes versus no) | 2.3 | −17.5 to 26.9 | 0.84 | 13.8 | −8.9 to 42.2 | 0.25 | |||
| On fosamprenavir (yes versus no) | 7.0 | −22.9 to 48.6 | 0.68 | 19.2 | −14.9 to 66.8 | 0.31 | |||
LPV, lopinavir; /r, ritonavir boosted; DF, disoproxil fumarate.
Multivariable model 1: concomitant antiretroviral drugs not considered.
Multivariable model 2: considering concomitant antiretroviral drugs.
Both multivariable models are adjusted for hours since last lopinavir intake.
All results with P < 0.05 are shown in bold.