Table 1. Pharmacokinetics and drug interactions of etravirine.

Pharmacokinetic variable	Value or corresponding parameter(s)
Tmax	2.5–4 h
Half-life (T1/2)	41 h
Primary metabolism	Hepatic
Substrate of enzymes	CYP3A4, CYP2C9 and CYP2C19
Enzymes induced	CYP3A4
Enzymes inhibited	CYP2C9 and CYP2C19
Plasma protein binding	99.9%, with 99.6% bound to albumin
Dose adjustment in hepatic failure	Child–Pugh Class A and B: no dose adjustment Child–Pugh Class C: not evaluated
Hepatitis B and/or C coinfection	No dose adjustment
Renal failure	No dose adjustment <1.2% of the dose is excreted in the urine, with no secretion of active drug
Hemodialysis	Highly bound to plasma proteins and unlikely to be removed by dialysis
Pregnant women, nursing mothers and pediatric population	Not studied
Do not coadminister with	Tipranavir/ritonavir, fosamprenavir/ritonavir and atazanavir/ritonavir Ritonavir at full dose (600 mg twice daily) Protease inhibitors without low-dose ritonavir Other non-nucleoside reverse transcriptase inhibitors Carbamazepine, phenobarbital, phenytoin, rifampin and rifapentine Rifabutin (when combined with a boosted protease inhibitor) St John's Wort (Hypericum perforatum)
Coadminister with caution	Lopinavir/ritonavir Antiarrhythmics (measurement of antiarrhythmic drug levels is recommended) Systemic dexamethasone, cyclosporine, sirolimus and tacrolimus Other substrates, inhibitors, or inducers of CYP3A4, CYP2C9 or CYP2C19

Taken from [17].