Could olanzapine be a new choice for the treatment of opioid withdrawal?

Opioid withdrawal is a clinical presentation with mental and physical symptoms. There are two pharmacological approaches to opioid dependence treatment; those based on opioid withdrawal and those based on agonist maintenance. Effective treatment of withdrawal symptoms is important for long-term outcome of detoxification. Opioid full agonists and partial agonists are drugs that are widely used in treatment of opioid withdrawal. α2-agonists such as clonidine and lofexidine are non-opioid drugs used for withdrawal situated in the literature. In recent years, there are studies aiming to investigate direct and indirect effects on the symptoms of opioid withdrawal of other psychotropic medications that effects via receptor systems like serotonin, norepinephrine, histamine, acetylcholine, dopamine, GABA, glutamate. Olanzapine is an atypical antipsychotic that blocks dopaminergic, serotonergic, adrenergic, histaminergic, and muscarinic receptors. It is widely used in various psychiatric emergencies for the treatment of irritability and psychomotor agitation. In both cases presented here, it was observed that olanzapine, which was given due to agitation, reduced withdrawal symptoms.

Case 1: A 20 years old male patient that had been using 1 g of heroin per day since one year, was admitted to our clinic upon his will to end his opioid addiction. The patient was hospitalized with the diagnosis of opioid addiction. Buprenorphine/naloxane administration was planned as induction therapy. Nonsteroidal analgesics were given to the patient, who showed early withdrawal symptoms. Adequate amount of time that is suggested for safe administration of buprenorphine had not been passed. 10 mg of olanzapine was injected to the patient since his withdrawal symptoms did not regress and showed agitation. Regression of the agitation and also objective and subjective withdrawal symptoms were observed clinically.

Case 2: A 25 years old male patient that had been using 1 g of heroin per day since two years was admitted to our clinic with the diagnosis of opioid addiction. Buprenorphine / naloxane administration was planned as induction therapy. The patient showed early withdrawal symptoms before the adequate amount of time that is suggested for safe administration of buprenorphine had not been passed. 10 mg of olanzapine was injected to the patient because he showed agitation. Regression of the agitation and objective and subjective withdrawal symptoms was observed clinically. Available data indicate that activation of the noradrenergic cells in the locus ceruleus played an important role in the symptoms of opiate withdrawal. An animal study indicates the possible involvement of the α2-adrenoreceptors in olanzapine antinociception. There are two clinical studies in the literature that showed efficacy of olanzapine on the withdrawal symptoms. Olanzapine compared to chlorpromazine in a 21-day study, was more effective in appetite, sleep, restlessness, agitation and craving. The opioid dependent patients with antisocial personality disorder in the one month follow-up results of a comparative study, irritability, verbal and physical hostility, restlessness has shown to reduce in the 10-30 mg/day of olanzapine in the treatment. Olanzapine could be an alternative in the treatment of opioid withdrawal.