Absence of Opioid Withdrawal Symptoms in Patients Receiving Methadone and the Protease Inhibitor Lopinavir‐Ritonavir

Abstract
A study was designed to determine the interactions, both clinical and pharmacokinetic, between methadone and lopinavir-ritonavir. Results demonstrated a 36% reduction in the methadone area under the plasma concentration—time curve after the introduction of lopinavir-ritonavir, with no coincident symptoms of opioid withdrawal and no requirement for methadone dose adjustment.