Methadone taper for narcotic-dependent neonates

(Version 1.0 07/01/01 to 03/15/04)

Narcotic analgesics (at VUMC, most frequently fentanyl) are commonly used in surgical neonates for the management of post-operative pain and in infants requiring mechanical ventilation for the treatment of agitation and discomfort.

            Neonates who have received significant doses or prolonged infusions of fentanyl will experience opiate withdrawal symptoms if the drug is suddenly discontinued.  50% of neonates who have received > 1.5 mg total dose or an infusion for > 5 days will experience abstinence symptoms; while 100% of neonates receiving a total dose of fentanyl > 2.5 mg or an infusion for > 9 days will withdraw.

            When discontinuing narcotics, the drug dosage/infusion rate should be decreased slowly, and infants at significant risk for or with any symptoms of neonatal abstinence syndrome should receive a methadone taper.

Standard Methadone Taper

While continuing fentanyl, begin methadone at 0.1 mg/kg/dose IV q 6 hours. 

Also, order a prn dose of methadone for breakthrough agitation:

      methadone 0.05 mg/kg/dose IV q 2-4 hours.

(Note: for an infant receiving atypically high doses of fentanyl, the pharmacy can help to calculate an appropriate equivalent dose of methadone at which to start the taper.  Then proceed as directed below.)

After the third methadone dose, cut the fentanyl dose in half, and after the fourth dose of methadone, discontinue fentanyl and continue the methadone q 6 hours and prn.

Important Note: The prn dose can be given at any time during the interval between the scheduled doses.

When no prn doses have been needed in a 24 hour period, increase the scheduled dosage interval for methadone to q 8 hours.  Continue the prn dose.

When no prn doses have been needed x 24 hours, increase the scheduled dosage interval for methadone to q 12 hours.  Continue the prn dose.

When no prn doses have been needed x 24 hours, increase the scheduled dosage interval for methadone to q 24 hours.  Continue the prn dose.

As long as the baby remains comfortable without signs of abstinence, decrease the dose of methadone by 10 - 20% every 2-3 days until discontinue scheduled methadone and prn dose.

(Note:  For practical purposes, given the extremely small doses our patients receive, you can effectively wean the q24h methadone dose by 0.01 mg every 1-3 days down to zero and discontinue the prn dose.)

Final note:  If IV access is lost when starting methadone, and fentanyl has not yet been discontinued, PO methadone should be started at 0.2 mg/kg/dose, with a PRN dose of 0.1 mg/kg/dose

References:

Taketomo CK, Hodding JH, Kraus DM. Pediatric Dosage Handbook, 8^th ed. 2001-2002. Lexi-Comp's Clinical Reference Library, pgs. 422-423.