Ritonavir (Norvir) is approved for use in children aged over two years in Europe and over one month in the United States. The recommended full dose for children is 350mg/m² twice daily, not exceeding 600mg twice daily. The starting dose is 250mg/m², increasing by 50mg/m² every two to three days until the final dose is reached. Triple drug combinations including ritonavir are effective in children, with similar side-effect profiles to adults, even in those with prior treatment exposure^{[1][2][3][4][5]}. The approval of ritonavir for children aged as young as one month was based on good results of a combination of ritonavir, AZT (zidovudine, Retrovir) and 3TC (lamivudine, Epivir) in 50 HIV-positive children^[6].

The liquid formulation of ritonavir is very bitter. If children cannot stand the taste, it can be disguised by being given after peanut butter and followed with chocolate sauce or cheese. Alternatively, it can be mixed into chocolate milk.