Opioid Endocrinopathy
Opioid Endocrinopathy
Basic studies have shown that opioid therapy can increase prolactin (PRL) release. Opioid effects in humans are inconsistent and of unknown clinical significance. Opium smokers in Iran were found to have a dose-dependent increase in PRL that was not observed in cigarette smokers or nonsmoking controls (25.61 ng/mL in opium smokers compared to 8.83 ng/mL in controls, P<.05). Narcotic addicts treated with methadone or buprenorphine have been shown to have normal PRL levels not significantly different from controls. Abs et al did not find abnormal PRL levels after intrathecal opioid administration. An increase in serum PRL levels was found in 16 of 39 patients taking opioids chronically, but no increment was observed in the control group (P<.001).
While some studies report PRL elevations among opioid users, the prevalence and significance are unclear. Hyperprolactinemia causes hypogonadism, possibly lowering testosterone levels in males taking opioids. The type of opioid and the method and length of administration may differentially affect the dopaminergic system, accounting for variable PRL levels. There may also be an intrinsic opioid effect on PRL secretion that is separate from dopamine control. A larger, longitudinal study is needed to determine the chronic effects of opioids on PRL regulation and any clinical consequences.
Prolactin
Basic studies have shown that opioid therapy can increase prolactin (PRL) release. Opioid effects in humans are inconsistent and of unknown clinical significance. Opium smokers in Iran were found to have a dose-dependent increase in PRL that was not observed in cigarette smokers or nonsmoking controls (25.61 ng/mL in opium smokers compared to 8.83 ng/mL in controls, P<.05). Narcotic addicts treated with methadone or buprenorphine have been shown to have normal PRL levels not significantly different from controls. Abs et al did not find abnormal PRL levels after intrathecal opioid administration. An increase in serum PRL levels was found in 16 of 39 patients taking opioids chronically, but no increment was observed in the control group (P<.001).
While some studies report PRL elevations among opioid users, the prevalence and significance are unclear. Hyperprolactinemia causes hypogonadism, possibly lowering testosterone levels in males taking opioids. The type of opioid and the method and length of administration may differentially affect the dopaminergic system, accounting for variable PRL levels. There may also be an intrinsic opioid effect on PRL secretion that is separate from dopamine control. A larger, longitudinal study is needed to determine the chronic effects of opioids on PRL regulation and any clinical consequences.