How the interaction occurs:
Efavirenz and nevirapine may speed up how quickly your liver processes methadone.
What might happen:
The amount of methadone in your blood may decrease and it may not work as well.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want to change the dosage of your methadone. Let your doctor know if your methadone does not seem to be working as well or you have any symptoms of withdrawal.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Clarke SM, Mulcahy FM, Tjia J, Reynolds HE, Gibbons SE, Barry MG, Back DJ. The pharmacokinetics of methadone in HIV-positive patients receiving the non-nucleoside reverse transcriptase inhibitor efavirenz. Br J Clin Pharmacol 2001 Mar;51(3):213-7.
2.Sustiva (efavirenz) US prescribing information. Bristol-Myers Squibb Company May 23, 2014.
3.Atripla (efavirenz/emtricitabine/tenofovir disoproxil fumarate) US prescribing information. Gilead Sciences, Inc. October, 2013.
4.Dolophine (methadone hydrochloride) US prescribing information. Roxane Laboratories, Inc. April, 2015.
5.Stocker H, Kruse G, Kreckel P, Herzmann C, Arasteh K, Claus J, Jessen H, Cordes C, Hintsche B, Schlote F, Schneider L, Kurowski M. Nevirapine significantly reduces the levels of racemic methadone and (R)-methadone in human immunodeficiency virus-infected patients. Antimicrob Agents Chemother 2004 Nov;48(11):4148-53.
6.Bano Rodrigo MD, Agujetas Rodriguez M, Lopez Garcia ML, Guillen Llera JL. Nevirapine induces abstinence symptoms in patients on a methadone maintenance program with HIV infection. Rev Clin Esp 2000 Jan;200(1):12-4.
7.Pinzani V, Faucherre V, Peyriere H, Blayac JP. Methadone withdrawal symptoms with nevirapine and efavirenz. Ann Pharmacother 2000 Mar; 34(3):405-7.
8.Marzolini C, Troillet N, Telenti A, Baumann P, Decosterd LA, Eap CB. Efavirenz decreases methadone blood concentrations. AIDS 2000 Jun 16; 14(9):1291-2.
9.Viramune (nevirapine) US prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc. January, 2014.
10.de la Cruz Pellin M, Esteban J, Gimeno C, Mora E. Interaction between methadone and antiretrovirals (stavudine, indinavir, ritonavir, nevirapine). Med Clin (Barc) 2003 Oct 4;121(11):439.
11.Bachiller Luque P, Flores AM, de Hoyos Llorente M, Navarro Canadas C. Methadone withdrawal syndrome induced by nevirapine. Med Clin (Barc) 2000 Mar 18;114(10):399.
12.Otero MJ, Fuertes A, Sanchez R, Luna G. Nevirapine-induced withdrawal symptoms in HIV patients on methadone maintenance programme: an alert. AIDS 1999 May 28;13(8):1004-5.
13.Heelon MW, Meade LB. Methadone withdrawal when starting an antiretroviral regimen including nevirapine. Pharmacotherapy 1999 Apr;19(4):471-2.
14.Altice FL, Friedland GH, Cooney EL. Nevirapine induced opiate withdrawal among injection drug users with HIV infection receiving methadone. AIDS 1999 May 28;13(8):957-62.