Methadone: Drug Interactions

Methadone: Drug Interactions

 


 

(Q): Your 28 year old male patient who is stable on methadone maintenance treatment presents with reduced effectiveness and symptoms of mild withdrawal from methadone. He was recently initiated on new medication by his primary care physician.

Which of the following medication may lower serum methadone level or decrease methadone effects?

 


 

BEFORE SCROLLING DOWN ==>

SUBMIT YOUR ANSWERS FIRST 🙂

.

.

.

.


 

DECREASE METHADONE

Carbamazepine

CYP3A4 and CYP2B6 enzyme induction.

Clinical Tip: This effect is not seen with valproate.

Phenobarbital

This can result in marked decrease in methadone.

Clinical Tip: methadone dose increase may be required.

Phenytoin

This can result in marked decrease in methadone due to CYP3A4 and CYP2B6 enzyme induction.

Dexamethasone

CYP3A4 and CYP2B6 enzyme inducer.

St. John’s Wort

Induces CYP3A4 and P-glycoprotein.

INCREASE METHADONE

Fluvoxamine

Among SSRIs, Fluovoxamine have strongest effect.

Clinical Tip: avoid fluvoxamine with methadone.

 

Note: cases of possible mild elevations of methadone with fluoxetine, paroxetine, nefazodone, sertraline.

Clinical Tip: If possible use other antidepressants with methadone.

   

ANTIBIOTICS: erythromycin, clarithromycin, Ciprofloxacin, Metronidazole

CYP450 enzyme inhibitor.

ANTIGUNGAL: fluconazole, ketoconazole

 

Cimetidine

CYP450 enzyme inhibitor.

Omeprazole

possibly by affecting methadone absorption.

Verapamil

Inhibits CYP3A4 and P-glycoprotein.

grapefruit juice

Inhibits intestinal CYP3A4 and P-glycoprotein.

 

Source: Alvares and Kappas 1972; Faucette et al. 2004; Gourevitch 2001; Liu and Wang 1984; Plummer et al. 1988; Bochner 2000; Kuhn et al. 1989; Saxon et al. 1989; Eap et al. 2002; Finelli 1976; Kreek 1986; Tong et al. 1981;Eich-Höchli et al. 2003; Scot and Elmer 2002Dawson and Vestal 1984; Sorkin and Ogawa 1983; Strang 1999;Bailey et al. 1998; Dresser et al. 2000; Hall et al. 1999;Benmebarek et al. 2004; Eagling et al. 1999; de Castro et al. 1996; Strang 1999; Levy et al. 2000.

Please do post your questions or comments below. 


Dr. Harvinder Singh, M.D. (Admin)


Enroll in our online course to have access to all important clinically relevant psychiatry topics in one place.


Related Articles