Growth Retardation in Young Mice Treated with dl-Methadone

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Science  07 Sep 1973:
Vol. 181, Issue 4103, pp. 947-949
DOI: 10.1126/science.181.4103.947


Newborn mice injected daily for 6 weeks with dl-methadone in dosages of 2 to 8 milligrams per kilogram grew significantly more slowly than their saline-treated littermates. Litters given d-methadone, 4 milligrams per kilogram, grew normally. Concomitant treatment with naloxone, 10 milligrams per kilogram, prevented growth inhibition. A weight deficit persisted in mice observed 6 weeks after cessation of methadone treatment.