Ritonavir-boosted lopinavir (LPV/r) is a protease inhibitor used for the treatment of human immunodeficiency virus (HIV) infection in both normal patients and in certain situations. In patients with renal failure, LPV/r does not require dosage adjustment because it is metabolized in the liver. Cohort studies have shown that the incidence of varying degrees of renal disease and/or crystalluria related to combination antiretroviral therapy with tenofovir and some protease inhibitors (PI) does not appear with LPV/r or that the incidence is much lower with this combination. Neurocognitive impairments are described in a high proportion of patients with HIV infection and viral replication or related inflammatory activity in the subarachnoid space. In these patients, LPV/r is one of the therapeutic options. A score has been published that rates antiretroviral drugs according to the concentration attained in the cerebrospinal fluid (CSF). LPV/r levels reached in CSF exceed the IC50 of wild-type HIV and has a valuable score (score 3) of the drugs currently used. The most important comorbid condition is chronic hepatitis, due to its frequency and because the biotransformation of LPV/r occurs in the liver. In these circumstances, it is important to evaluate the influence of liver failure on blood drug levels and how these values may cause liver toxicity. LPV/r dose modification has not been established in the presence of liver failure. LPV/r-induced liver toxicity has only been reported with a certain frequency when liver enzymes were elevated at baseline or in patients with chronic hepatitis C, although most cases of liver toxicity were mild.