D2 receptor blockade by flunarizine and cinnarizine explains extrapyramidal side effects. A SPECT study.

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Brucke T, Wober C, Podreka I, Wober-Bingol C, Asenbaum S, Aull S, Wenger S, Ilieva D, Harasko-van der Meer C, Wessely P, et al.

D2 receptor blockade by flunarizine and cinnarizine explains extrapyramidal side effects. A SPECT study.

J Cereb Blood Flow Metab. 1995 May;15(3):513-8.

PubMed ID
7714010 [ View in PubMed
]
Abstract

Twenty-six patients under treatment with the calcium channel blockers flunarizine (Fz) or cinnarizine (Cz) were examined-with single-photon emission computed tomography using [123I]iodobenzamide as a ligand. The striatal dopamine D2 receptor-binding potential was determined and found to be reduced by 14 to 63% (39.5 +/- 15.0%; p < 0.0001) in patients compared with age-matched control values. This reduction was larger in 12 patients with extrapyramidal symptoms and was only slowly reversible after discontinuation of treatment. Patients treated for > 6 months had significantly larger reductions than patients treated for a shorter period. Parkinsonian symptoms were only seen in patients older than 50 years. Our findings prove a neuroleptic-like action of Fz and Cz, which seems to be the major reason for their extrapyramidal side effects. Older age and long-term treatment are predisposing factors for these effects.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
CinnarizineDopamine D2 receptorProteinHumans
No
Other/unknown
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