Although olanzapines metabolism includes the minor metabolic pathway of CYP2D6, the presence of the CYP2D6 inhibitor fluoxetine does not have a clinically significant effect on olanzapines clearance. Pharmacology
Pharmacodynamics
Olanzapine was first discovered while searching for a chemical analog of clozapine that would not require hematological monitoring. Investigation on a series of thiophene isosteres on 1 of the phenyl rings in clozapine, a thienobenzodiazepine analog (olanzapine) was discovered.Olanzapine has a higher affinity for 5-HT2A serotonin receptors than D2 dopamine receptors, which is a common property of most atypical antipsychotics, aside from the benzamide antipsychotics such as amisulpride along with the nonbenzamides aripiprazole, brexpiprazole, blonanserin, cariprazine, melperone, and perospirone. Olanzapine had the highest affinity of any second-generation antipsychotic towards the P-glycoprotein in one in vitro study. P-glycoprotein transports a myriad of drugs across a number of different biological membranes (found in numerous body systems) including the blood-brain barrier (a semipermeable membrane that filters the contents of blood prior to it reaching the brain); P-GP inhibition could mean that less brain exposure to olanzapine results from this interaction with the P-glycoprotein. A relatively large quantity of commonly encountered foods and medications inhibit P-GP, and pharmaceuticals fairly commonly are either substrates of P-GP, or inhibit its action; both substrates and inhibitors of P-GP effectively increase the permeability of the blood-brain barrier to P-GP substrates and subsequently increase the central activity of the substrate, while reducing the local effects on the GI tract.
A patient developed this chorea with no definite evidence of previous Sydenhams chorea or recent streptococcal infections, but had anti-basal ganglia antibodies, suggesting immunological basis for the pathophysiology of this chorea. Diagnosis
Differential diagnoses
Chorea can also be a manifestation of drug toxicity (for example, anticonvulsants, antiparkinson agents, neuroleptics, steroids, and estrogen), or a result of an infectious disease such as meningovascular syphilis, Lyme disease, viral encephalitis, and many others. Treatment
Drug treatment is indicated for patients with severe disabling chorea. It is treated with haloperidol, chlorpromazine alone or in combination with diazepam, and also pimozide, which is another neuroleptic drug which may have fewer adverse effects than haloperidol. Valproic acid, chloral hydrate, risperidone, or phenobarbital can also be used. See also
Chorea

References
Further reading
Palanivelu, L. M. (2007). "Chorea gravidarum". Journal of Obstetrics & Gynaecology. 27 (3): 310. doi:10.1080/01443610701241134. PMID 17464821. S2CID 119999. == External links ==