HIV 101: Drug Interactions With HAART and Methadone

DrugEffect of Antiretroviral Therapy on MethadoneEffect of Methadone on Antiretroviral Therapy
Nucleoside/Nucleotide Analogues
AbacavirDecreased methadone clearance 25%Decreased abacavir peak concentration 34%
Didanosine, buffered tabletUnknownDecreased didanosine AUC 57%
Didanosine, enteric-coated capsuleUnknownNo significant change in didanosine AUC
LamivudineUnknownNo significant change when given as zidovudine-lamivudine
StavudineUnknownDecreased stavudine AUC 23%
Tenofovir disoproxil fumarateUnknownNo significant change in tenofovir DF
ZalcitabineUnknownUnknown
ZidovudineUnknownIncreased zidovudine AUC 41%
Non-Nucleoside Analogues
DelavirdineUnknown, although potential increased methadone effectNo change in delavirdine or N-delavirdine
EfavirenzDecreased methadone levels 57%Unknown
NevirapineDecreased methadone levels 51%Unknown
Protease Inhibitors (PIs)
AmprenavirDecreased methadone AUC 35%Decreased amprenavir AUC, Cmax, Cmin
IndinavirNo significant change in methadone AUCInsignificant change in indinavir AUC; increased indinavir Cmin 50%-100%; decreased indinavir Cmax 16%-36%
Lopinavir-ritonavirDecreased methadone AUC 36%Unknown
NelfinavirDecreased methadone AUC 40%Decreased nelfinavir metabolite (M8) AUC 53%; clinical significance unknown
RitonavirDecreased methadone AUC 36%Unknown
Saquinavir, hard-gel capsuleUnknown with saquinavir as sole PIUnknown with saquinavir as sole PI
Saquinavir, soft-gel capsuleUnknown with saquinavir as sole PI; unbound methadone concentrations unchanged when using saquinavir and ritonavir concurrentlyUnknown with saquinavir as sole PI; potential reduction in saquinavir Cmin when using saquinavir and ritonavir concurrently
AUC, area under the concentration time curve; Cmax, maximum drug concentration or peak level; Cmin, minimum drug concentration or trough level. Drug Interactions Associated With HAART: Focus on Treatments for Addiction and Recreational Drugs. AIDS Reader 13(9):433-450, 2003. Available at www.medscape.com/viewarticle/461892_4.