HARCP Archives

Browse by article

Browse by volume

Heroin Addiction and Related Clinical Problems: 2010, 12, 3 (pages: 21 - 30)

Clinical foundations for the use of methadone in patients with infectious diseases

Somaini L., Pacini M., Maremmani I.

Summary: The immune system is an organization of cells and molecules with specialized roles in defending against infection. Communication between the central nervous and the immune system lies at the hart of the neuroimmune axis. There are several data indicating that opioids drugs may influence the immune system. One of the main features of opioid induced alteration of immune function is the development of immunosuppression. However, evidence has been provided to suggest that different opioids drugs may have distinctive effects on the immune system. Methadone is a widely used synthetic 3,3-diphenylpropylamine opioid which primarily acts at the μ opioid receptor. Its most common use is in the therapy for opioid dependence. Besides to their therapeutic efficacy, opioids can produce several well known adverse events, and, as has recently been recognized, can positively interfere with the immune response. Infact, data obtain from animal and human studies have demonstrated that long acting opioids drugs such as methadone is devoid of any intrinsic immunosuppressive activity. This effect may partly depend on the ability of methadone to restore the HPA axis function, that is altered in heroin dependent patient, or by the long-lasting activation of opioid receptors both in the central nervous system and on immune competent cells. HIV and HCV infections are the most frequent infectious disease seen in drugs users. Opioids may facilitate the outbreak of infections through marked immunomodulating effects on the immune respsoses against a virus. The enrolment of heroin patient in MMT programs represents a particularly effective measure for the prevention of HCV and HIV virus transmission and the immunorestoring properties of methadone are particularly relevant in the treatment of concurrent infectious such as HCV frequently associated with heroin addiction. It is evident that the possibility to reach an adequate control of addiction and of concomitant infectious diseases choosing either immunosuppressive drugs or drugs characterized by immunoneutral or immunostimulating effects could represent an important point to be considered in the future in opioid therapy.