Abstract | RATIONALE: OBJECTIVES: METHODS: Thirteen patients with schizophrenia participated. PET examinations were performed on patients treated with clinical dosage of blonanserin or olanzapine alone. A crossover design was used in which seven patients switched drugs after the first scan, and PET examinations were conducted again. D2 and D3 receptor occupancies were evaluated by [ 11C]-(+)-PHNO. We used nondisplaceable binding potential (BPND) of 6 healthy subjects which we previously reported as baseline. To consider the effect of upregulation of D3 receptor by continued use of antipsychotics, D3 receptor occupancy by blonanserin in seven subjects who completed 2 PET scans were re-analyzed by using BPND of olanzapine condition as baseline. RESULTS: Average occupancy by olanzapine (10.8 ± 6.0 mg/day) was as follows: caudate 32.8 ± 18.3%, putamen 26.3 ± 18.2%, globus pallidus - 33.7 ± 34.9%, substantia nigra - 112.8 ± 90.7%. Average occupancy by blonanserin (12.8 ± 5.6 mg/day) was as follows: caudate 61.0 ± 8.3%, putamen 55.5 ± 9.5%, globus pallidus 48.9 ± 12.4%, substantia nigra 34.0 ± 20.6%. EC50 was 0.30 ng/mL for D2 receptor for caudate and putamen (df = 19, p < 0.0001) and 0.70 ng/mL for D3 receptor for globus pallidus and substantia nigra (df = 19, p < 0.0001). EC50 for D3 receptor of blonanserin changed to 0.22 ng/mL (df = 13, p = 0.0041) when we used BPND of olanzapine condition as baseline. CONCLUSIONS:
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Authors | Takeshi Sakayori, Amane Tateno, Ryosuke Arakawa, Woo-Chan Kim, Yoshiro Okubo |
Journal | Psychopharmacology
(Psychopharmacology (Berl))
Vol. 238
Issue 5
Pg. 1343-1350
(May 2021)
ISSN: 1432-2072 [Electronic] Germany |
PMID | 33180175
(Publication Type: Journal Article)
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Chemical References |
- Antipsychotic Agents
- Piperazines
- Piperidines
- Receptors, Dopamine D2
- Receptors, Dopamine D3
- blonanserin
- Olanzapine
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Topics |
- Adult
- Aged
- Antipsychotic Agents
(therapeutic use)
- Cross-Over Studies
- Female
- Humans
- Male
- Middle Aged
- Olanzapine
(therapeutic use)
- Piperazines
(pharmacology)
- Piperidines
(pharmacology)
- Positron-Emission Tomography
(methods)
- Putamen
(metabolism)
- Receptors, Dopamine D2
(metabolism)
- Receptors, Dopamine D3
(metabolism)
- Schizophrenia
(drug therapy)
- Young Adult
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