The Department of Health recently sent out a notice reminding practitioners that double dosing of LPV/r (as we do for adults) in children on rifampicin-containing TB treatment is not recommended.

The notice was sent out after concerns were raised by the third line antiretroviral committee regarding the number of cases of protease inhibitor resistance that have been observed, possibly as a result of unboosted or double dosing of LPV/r in young children on rifampicin-containing TB treatment.

Current LPV/r formulations consist of LPV to ritonavir in the ratio of 4:1. Double dosing does not maintain adequate levels of LPV in young children on rifampicin-containing TB regimens, however increasing the dose of ritonavir, so that the ratio of LPV to ritonavir is 1:1, can result in adequate levels of LPV.

The STGs and EML recommends additional ritonavir of 0.75 times the LPV dose, 12 hourly, for the duration of rifampicin containing TB treatment. This should be continued for two weeks after completion of rifampicin-containing TB treatment. The table below is extracted from the Paediatric Hospital Level STGs and EML:

If a higher dose of ritonavir is used, additional adverse reaction monitoring must be done.