Increased Serum Thyroxine Levels in Euthyroid Narcotic Addicts¹

Abstract

Twenty-two percent of 285 untreated, nongoitrous euthyroid narcotic addicts had serum thyroxine (T 4 ) levels above the upper limits of normal. The serum triiodothyronine (T 3 ) resin uptake was below the lower limits of normal in either 57% or 25% of the subjects depending on the assay method used. The mean thyroxinebinding globulin binding capacity in a small sample was significantly above that in a group of nonaddicts but within the normal range. Both absolute free thyroxine, when measured, and the free thyroxine index were normal in this 80% male population. There was no correlation of abnormal thyroid function with the history of specific drugs abused and there was no clinical evidence of hyperestrogenism. It appeared that successful methadone treatment was accompanied often by a return towards normal of T 4 levels and T 8 uptake. Thirty-six chronic methadone maintained patients had essentially normal T 4 measurements, and the T 3 resin uptake was normal in all in whom it was measured. Narcotic addiction may result in abnormalities of thyroxine transport which may produce distortions in some commonly used thyroid ftmction tests. (/ Clin Endocrinol Metab 37: 928, 1973)

Effect of Chronic Methadone Administration on Neuroendocrine Function in Developing Rats

“…These findings contrast with reports of unchanged or elevated thyroid hormone levels in adult rats and humans that are addicted to opiates [Shenkman et al, 1972;Azizi et al, 1974;Webster et al, 1973], suggesting that opiate effects on thyroid func tion differ with species, age and duration of treatment. While there are reports that thyroid hormone levels are elevated in human newborns that are experiencing narcotic withdrawal, this elevation has been attributed to the stress associated with withdrawal [Rosenfeld et al, 1981].…”

Long-Term Pharmacotherapy for Opiate (Primarily Heroin) Addiction: Opioid Agonists

“…A few abnormalities in thyroid function tests have also been observed in heroin addicts and in methadone-maintained patients (WEBSTER et al 1973;AZIZI et al 1974;CUSHMAN and KREEK 1974a;BASTOMSKY and DENT 1976;KREEK 1978a;SPAGNOLLI et al 1987). Initially, it was thought that thyroid function might be deranged; however, further studies revealed that thyroid function is normal in methadone-maintained patients.…”

“…As part of the prospective studies, the effects of ascending and then stabilized, moderate to high doses (60-120 mg/day) of the long-acting opioid methadone as used in treatment on neuroendocrine function and numerous other aspects of normal physiology, were rigorously assessed. In addition, clinical observations were made by many clinicians and clinical investigators at other institutions involved in early methadone maintenance treatment efforts (BUNICK 1968;CUSHMAN et al 1970;CUSHMAN 1972CUSHMAN , 1973aDREEK 1972DREEK , 1973aDREEK ,b, 1978aDREEK , 1983bSHENKMAN et al 1972;MARKS and GOLDRING 1973;SANTEN and BARDIN 1973;WEBSTER et al 1973;AzlZI et al 1973AzlZI et al , 1974ESPEJO et al 1973;CUSHMAN and KREEK 1974a,b;SANTEN 1974;CICERO et al 1975;HELLMAN et al 1975;SANTEN et al 1975). A limited number of earlier studies on the effects of opiate addiction on endocrine function had been conducted at Lexington (EISENMAN et al 1958(EISENMAN et al , 1961(EISENMAN et al , 1969MARTIN and JASINSKI 1969;MARTIN et al 1973).…”

Serum triiodothyronine determination in clinical use.

“…While caution must be exercised in drawing inferences from animal studies and applying them to the human it remains a possibility that heroin was having a similar effect in the patients addicted to this drug. However, in a series of clinically euthyroid heroin addicts studied by Webster et al (1973) an increased mean serum T4 level was observed as a result of an elevated serum TBG binding capacity. Serum T3 levels were not measured.…”