Mirtazapine Induced Akathisia: Understanding a Complex Mechanism

Propranolol for mirtazapine-induced akathisia: Single case report

“…There is evidence to support the use of beta blockers, mirtazapine, benztropine, and benzodiazepines from small clinical trials of subjects with antipsychotic-induced akathisia,6,7,9 but no trials regarding the treatment of antidepressant-induced symptoms. The majority of existing publications regarding the treatment of mirtazapine-induced akathisia found the most efficacy with discontinuation of the mirtazapine2 or initiation of diazepam4 or other benzodiazepines 5. In this unique case, given the patient's history of substance use disorder, benzodiazepines were not considered.…”

“…Other factors could have contributed to these findings, however the risk of substance use or withdrawal is low, given sobriety in a controlled environment for 1 month prior to this presentation. Akathisia has been reported as a side effect to mirtazapine in several cases, with hypothesized mechanism by Raveendranathan and Swaminath2 being related to alpha 2 receptors. While the exact mechanism is still unknown it seems clear the mechanism is different than that of antipsychotic-induced akathisia, given the body of evidence supporting the efficacy of mirtazapine can be an effective treatment in those cases.…”

“…While akathisia and psychomotor restlessness are listed as “warnings and precautions” occurring in less than 1% of the population prescribed mirtazapine,1 you can find more research citing mirtazapine as a treatment for antipsychotic-induced akathisia than case reports establishing it as the culprit 2-5. In fact, a head-to-head trial6 comparing the efficacy of mirtazapine to propranolol for antipsychotic-induced akathisia found mirtazapine to be as effective, if not better, and a well-tolerated treatment approach.…”

Risperidone-induced tardive akathisia: A rare antipsychotic side effect with management issues

“…Although acute akathisia can be caused by both neuroleptic and nonneuroleptic drugs (selective serotonin reuptake inhibitors, noradrenergic and specific serotonergic antidepressant, antiemetics, etc. ),[56] no reports of TA ascribed to nonneuroleptics are there in the literature. [4] TA has been reported with both typical antipsychotics such as haloperidol, perphenazine, molindone, loxapine, and thioridazine,[7] and atypical antipsychotics such as olanzapine,[8] amisulpride,[9] clozapine,[10] risperidone, and levomepromazine.…”

Mirtazapine-associated movement disorders: A literature review

“…For 1990 and 2019, a total of 52 reports containing 179 individuals that developed a MD associated with MTZ were identified from 20 different countries [ Table 1 ] [ 10 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 ]. 103 individuals were from European countries, 49 Asian, 17 Australian, 8 North American, and 2 South American.…”