RESEARCH MONOGRAPH · KDC-MN-234
Olanzapine
Olanzapine (Zyprexa) is the closest pharmacological cousin of clozapine, brought to market by Eli Lilly in 1996 specifically to capture clozapine's effectiveness without its agranulocytosis risk. That worked: olanzapine is reliably one of the more effective antipsychotics for schizophrenia and acute mania, and patients do not need weekly blood draws. The trade-off is the worst metabolic profile of any drug in its class. Patients on olanzapine routinely gain 10 to 30 pounds, develop dyslipidemia, and progress to type 2 diabetes at high rates. Used for schizophrenia, acute mania, and treatment-resistant depression in combination with fluoxetine (the Symbyax product). The recent intramuscular long-acting injection (Zyprexa Relprevv) carries an unusual risk of post-injection delirium and sedation. Not stocked by Kodiac. This monograph is provided for research and educational reference.
Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.
Atypical antipsychotic
A thienobenzodiazepine atypical antipsychotic structurally and mechanistically related to clozapine, without the agranulocytosis risk.
Abstract
Olanzapine (2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine; CAS 132539-06-1; molecular formula C17H20N4S; molecular weight 312.43) is a thienobenzodiazepine atypical antipsychotic developed at Eli Lilly and approved by the FDA in 1996 under the trade name Zyprexa. The receptor profile is closely related to clozapine: D2 (Ki approximately 11 nM, higher affinity than clozapine), 5-HT2A (Ki approximately 4 nM), H1 (Ki approximately 0.087 nM, among the most potent in clinical use), alpha-1, muscarinic, 5-HT2C, 5-HT3, 5-HT6, 5-HT7. The structural difference from clozapine eliminates the agranulocytosis liability while preserving the broad-spectrum atypical pharmacology. Plasma half-life is 21 to 54 hours; metabolism is via CYP1A2 and direct glucuronidation. The compound carries the highest metabolic risk profile of any commonly used antipsychotic: dyslipidemia, weight gain (mean 4 to 12 kg over 12 weeks), and incident type 2 diabetes are well-documented, attributed to combined H1 and 5-HT2C antagonism. Approved for schizophrenia, bipolar I disorder, and treatment-resistant depression in combination with fluoxetine (Symbyax). Used as a reference broad-spectrum atypical antipsychotic.
Mechanism of action
Broad multireceptor antagonist (D2, 5-HT2A, H1, alpha-1, muscarinic, 5-HT2C/3/6/7). Highest metabolic risk profile in the antipsychotic class.
Reported research dose ranges
Clinical 5 to 20 mg per oral administration daily. Rodent studies 1 to 10 mg/kg/day.
References
- Bymaster FP, et al. Radioreceptor binding profile of the atypical antipsychotic olanzapine. Neuropsychopharmacology 1996.
- Newcomer JW. Second-generation (atypical) antipsychotics and metabolic effects. CNS Drugs 2005.
- Tollefson GD, et al. Olanzapine versus haloperidol in the treatment of schizophrenia. Am J Psychiatry 1997.
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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.