Lopinavir
Lopinavir is an antiretroviral of the protease inhibitor class. It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir (lopinavir/ritonavir). It was patented in 1995 and approved for medical use in 2000. Side effects. Side effects, interactions, and contraindications have only been evaluated in the drug combination lopinavir/ritonavir. Pharmacology. Lopinavir is highly bound to plasma proteins (98–99%). Reports are contradictory regarding lopinavir penetration into the cerebrospinal fluid (CSF). Anecdotal reports state that lopinavir cannot be detected in the CSF; however, a study of paired CSF-plasma samples from 26 patients  receiving lopinavir/ritonavir found lopinavir CSF levels above the IC in 77% of samples. Research. A 2014 study indicates that lopinavir is effective against the human papilloma virus (HPV). The study used the equivalent of one tablet twice a day applied topically to the cervices of women with high-grade and low-grade precancerous conditions. After three months of treatment, 82.6% of the women who had high-grade disease had normal cervical conditions, confirmed by smears and biopsies. Lopinavir has been shown to impair protein synthesis via AMP-activated protein kinase (AMPK) and eEF2 kinase (eEF2K) activation, a mechanism  that is similar to the antiviral effect of protein phosphatase 1 inhibitors. Lopinavir was found to inhibit MERS-CoV replication in the low-micromolar range in cell cultures. In 2020, lopinavir/ritonavir was found not to work in severe COVID-19. In this trial the medication was started typically around 13 days after the start of symptoms.