Kaletra has been approved for use in children aged two years and over in the European Union and six months and over in the United States. The standard dose is 230mg/m² lopinavir and 57.5mg/m² ritonavir twice daily. The standard adult dose is recommended when a child reaches 40kg. As in adults, the dosage is increased for children taking Kaletra with efavirenz (Sustiva) or nevirapine (Viramune)^[1].

A number of studies have confirmed that use of the liquid formulation of Kaletra can reduce viral loads in children who have never taken antiretroviral drugs before, as well as those with treatment experience^[2][3]. The side-effect profile of Kaletra is similar in children and adults.

Once-daily dosing with Kaletra has been attempted in one study in children. Using a dose of 460mg/m² lopinavir and 155mg/m² produced similar levels of lopinavir to the 800mg / 200mg once-daily dose used in adults. However, there was wide variability in the levels of lopinavir in the children, with younger children having drug levels that were too low^[4]. Consequently, once-daily dosing cannot be recommended until further studies are carried out.