Which is NOT used in treatment of heroindependence?
Disulfiram Pharmacological treatment of opioid dependence (Harrison 17' Ye p. 2732) Methadone maintenance: ? Methadone is a synthetic opioid chemically dissimilar but pharmacologically very similar to morphine. Methadone is used as substitution therapy in opioid dependence. The basic aim is to replace an opioid with another opioid that has the following propeies. - Lower abuse/addiction potential - Incapable of a giving a kick - Where tolerance develops slowly - Withdrawl syndrome develops gradually - Legally accessible - Can be taken orally and has a relatively long half life. These propeies of the drug help in blocking heroin induced euphoria while decreasing craving. - Methadone occupies the opioid receptor thus reducing the desire to take other opioids. - Addicts who are cooperative enough to take oral methadone experience reduced craving and less kick/buzz/rush from intravenous heroin because their opioid receptor are already occupied by methadone and the intravenous drug must compete with it. - This helps the patient to maintain abstinence for opioids. - Over three quaers off patients in well supervised clinics are likely to remain heroin free for 26 months. - After a period of maintenance (usually 6 months to -2. 1 year) the dose of methadone is gradually tapered off. Alternative medicines that have been used for maintenance treatment are:? Buprenorphine: - Buprenorphine is a paial agonist at the p receptor. Buprenorphine has several advantages over methadone. - Low overdose danger - Potentially easier detoxification than with methadone. - Probable ceiling effect in which higher doses do not increase euphoria. Opioid antagonists (Naltrexone) Naltrexone is a competitive opioid antagonist at it, cS, 7C It is long acting. It can be used orally to assist in the rehabilitation of ex opioid abusers who are fully withdrawn from opioids (otherwise it will induce an acute withdraw! syndrome). A patient who then takes an opioid fails to experience the "kick" or euphoria. Naltrexone does not reduce the craving. Use of clonidine in opioid withdrawl: -(Goodman Gilman 11th/e p. 619) Clonidine is an a2 adrenergic agonist that decreases adrenergic neurotransmission from locus ceruleus. Most of the autonomic symptoms of opioid withdrawl results from loss of opioid suppression of locus ceruleus. Clonidine acts distinct receptor but by cellular mechanisms that mimic opioid effects. So it can allete many of the symptoms of opioid withdrawl. Postural hypotension is common with opioid withdrawl, therefore, dose of clonidine, must be titrated according to the stage and severity of withdraw!. Ioxfexidine It is also an a2 adrenergic agonist. It has greater selectivity for a2Aadrenergic receptors and is associated with less hypotension.
Disulfiram
Buprenorphine
Clonidine
Lofexidine