Abbott announces therapeutic drug monitoring scheme for lopinavir/r

Graham McKerrow, HIV i-Base

Abbott Laboratories has announced the introduction of a therapeutic drug monitoring (TDM) scheme for its second generation protease inhibitor lopinavir/r (Kaletra), a coformulation of lopinavir and ritonavir. The scheme is being run in association with the Liverpool University TDM Service.

Kaletra capsules each contain 133.3mg of lopinavir and 33.3mg of ritonavir. Dr Ian Hitchcock, Abbott’s HIV medical adviser, says in a letter to doctors: “At the recommended dosage (400/100mg bd in adults) ritonavir has no antiretroviral activity but acts as a pharmacokinetic enhancer – slowing the clearance of lopinavir. This novel formulation gives rise to high and sustained plasma levels of lopinavir, which contribute towards durability and potentially provides a pharmacologic barrier to the emergence of viral resistance.”

Dr Hitchcock says that high plasma levels of lopinavir are generally achieved, but that on some occasions drug level monitoring may be considered appropriate to optimise antiretroviral therapy with lopinavir/r.

Abbott will sponsor analysis of blood samples by the Liverpool TDM Service for three types of patients: paediatric patients; patients receiving concomitant amprenavir with lopinavir/r; and patients receiving concomitant NNRTI therapy with lopinavir/r.

Dr Hitchcock tells physicians: “There will be no charge to your HIV treatment centre for the TDM analysis for lopinavir for patients meeting the required criteria. However, postage and packing costs will be the responsibility of the centre requesting the analysis, as will the cost of any additional assays requested with lopinavir (unless covered by other schemes).”

Request forms, and details of the service and how to request analysis are available from the Liverpool TDM Service website:

Information about lopinavir/r is available at Abbott’s site:

Health professionals seeking information about the service can contact Sara Gibbons at the Liverpool TDM Service on 0151 794 5553, email: or Dr Hitchcock on 01628 773355.


This programme is welcomed. A TDM form is also included on page 38 of this HTB, together with background information about the service and sample collection on pages 36-37.

Links to other websites are current at date of posting but not maintained.