Lopinavir/r use in children less than two years old promising results despite low plasma levels
Polly Clayden, HIV i-Base
Data are limited for children under 2 years of age treated with HAART.
A study from Konigs and co-workers In Frankfurt followed five young children that had initiated LPV/r containing therapy for up to 18 months.
The average age at initiation of therapy was 8.5 months (range: 1.2-22.0 months) and all children received AZT/3TC/LPV/r in liquid formulations. The LPV/r dose was 230mg/m2 BID.
At baseline 4/5 children had a viral load >1,000,000 copies/mL. This decreased by 2 logs within 2 to 4 weeks, after which the decrease was less rapid and reached <100 copies/mL after 6 to 10 months, with 1 child achieving <20 copies/mL.
CD4 counts remained stable for children initiating therapy earlier but immunocompromised children showed an increase from 23 to 36%.
The authors reported that LPV/r plasma levels were lower than has been described for older age groups. The average minimal concentration at I hour after administration was 1355ng/mL and at three hours after administration it was 2804ng/mL.
They noted that the children initially had difficulties with the LPV/r due to the taste of the formulation but once they got used to it, the children tolerated it well. Using LPV/r in HIV treatment regimens in children <2 years with high viral loads leads to a rapid drop and an increase in CD4 counts.
They suggest that observed low plasma levels should give rise to further studies evaluation dose adjustment for children below 2 years of age.
This study is tiny so it is difficult to comment on efficacy. More data on this drug in infants is urgently needed though as some guidelines (South Africas for example) are recommending LPV/r for infant first line therapy out of concern that their mothers may have been exposed to single dose nevirapine in MTCT programmes. The PK suggests this needs further investigation.
Konigs C, Dunsch D, von Hentig N et al. LPV/r (Kaletra) in children younger than 24 months rapid decrease in viral load and stable CD4 counts despite very low plasma levels. 3rd IAS Conference on HIV Pathogenesis and Treatment, Rio de Janeiro, 2005. Abstract MoPe92C11.