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S077-2

Methadone and Sexual Function

Anne Yee

Department of psyhological medicine, University Malaya center of addiction science, Faculty of medicine
University Malaya, Malaysia

Background/Objective: ethadone maintenance treatment (MMT) is a comprehensive treatment
program that involves the long-term prescribing of methadone as a substitution therapy for opioid
dependence. Despite the effectiveness of the methadone maintenance therapy, the meta-analytical
pooled prevalence for sexual dysfunction among methadone users was 52% (95% confidence
interval [CI], 0.39–0.65). In this meta-analysis, hypoactive sexual desire and low libido were the
most prevalent sexual dysfunctions compared to other sexual dysfunction, accounting for 51%.

Method: Methadone is the slow-and-long acting opiate agonist that cause the stimulation of mu
opiate receptors in the various area of the brain. There are few hypothesis that try to explain the
correlation of methadone and sexual dysfunction. One of well known hypothesis was the
neuroendocrinologic effects of methadone that exert on the tubero-infundibular and
hypothalamus-pituitary-gonadal (HPG) axis .

Result: The hypothesis that the chronic stimulation of the μ opiate receptors by methadone, alters
the functioning of the tubero-infundibular axis and the dopaminergic control of prolactin with the
consequential impact on sexual functioning was formulated . (8) A high level of circulating prolactin
causes inhibition of gonadotrophin releasing hormone which lowers levels of sex hormone,
especially testosterone. Another theory is the effects of the neurotransmitter dopamine on male
sexual behavior. The first recognized dopamine-mediated enhancement of sexual behavior in human
was when administration of l-dopa (3,4-dihydroxy-l-phenylalanine), the precursor to dopamine, to
men suffering from Parkinson's disease resulted in increased libido and sexual potency.

Conclusion: Management for methadone induced sexual dysfunction remain a challenge for the
physicians because the reducing or stopping the methadone in this group of patients may not be
always possible. Hence, the physicians need other stradegies to manage the sexual dysfunction
in this group of patients.