Methadone dosing strategies in HIV-infected injection drug users enrolled in a directly observed therapy program

We have measured methadone dose adjustments and treatment responses after nevirapine (NVP)-, efavirenz (EFV)-, ritonavir-boosted lopinavir (LPV/r), or atazanavir (ATV; with or without ritonavir)-based highly active antiretroviral therapy (HAART) was initiated in injection drug users (IDUs).

We identified 120 IDUs receiving HAART and methadone within a directly observed therapy (DOT) program. Follow-up was according to clinical standards, with changes in methadone dose being made as required to achieve clinical stabilization within the first 3 months of HAART.

The observed median methadone dose changes from baseline were 20 mg/d (P<0.001) in patients on NVP, with 32 (86%) of 37 patients requiring daily dose increases, and 7.5 mg/d (P=0.004) in patients on EFV, with 11 (61%) of 18 patients requiring daily dose increases. Conversely, median changes were 0 mg/d for patients on LPV/r (P=0.56) or ATV (P=0.95). Virologic suppression (HIV RNA<400 copies/mL) was achieved in 26 (70%) of 37, 12 (67%) of 18, 25 (76%) of 33, and 24 (75%) of 32 patients receiving NVP-, EFV-, LPV/r-, and ATV-based regimens, respectively (P=0.89).

Although methadone-based DOT can be a successful tool for the coadministration of HAART, careful monitoring is required to ensure that methadone withdrawal does not adversely affect the goals of treatment, particularly when nonnucleoside reverse transcriptase inhibitors are used.