Thiethylperazine-induced parkinsonism: in vivo demonstration of dopamine D2 receptors blockade.
Thiethylperazine (Torecan) is a piperazine phenothiazine employed to relieve vertigo. Its use may be associated with extrapyramidal side effects (dystonia, akathisia, tardive dyskinesia) (Sulkava, 1984), but parkinsonism has rarely been described. We describe a woman who, 1 month after the onset of thiethylperazine treatment, developed parkinsonism that disappeared 2 months after withdrawal of the drug. However, cerebral single-photon emission computed tomography (SPECT) with the dopamine (DA) D2 receptors ligand 123I-iodobenzamide (123I-IBZM) revealed a persistent reduced DA D2 receptors activity (by 45%) in the basal ganglia (BG), which may be clinically not effective.
Department of Neurosciences, University of Padova, Padova, Italy. chiara.briani@unipd.it
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Briani
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Cagnin
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Chierichetti
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Tiberio
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Battistin
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Pizzolato
D001479:Basal Ganglia / Q000000981:diagnostic imaging; D001549:Benzamides / Q000494:pharmacology*; D001931:Brain Mapping; D065127:Dopamine D2 Receptor Antagonists; D005260:Female; D006801:Humans; D007456:Iodine Isotopes; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000000981:diagnostic imaging*; D011759:Pyrrolidines / Q000494:pharmacology*; D013847:Thiethylperazine; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D001549:Benzamides; D065127:Dopamine D2 Receptor Antagonists; D007456:Iodine Isotopes; D011759:Pyrrolidines; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide; D013847:Thiethylperazine