title: Dyskinesia caused by ziconotide-baclofen combination in an adolescent affected by cerebral palsy.
abstract: OBJECTIVE
  To report on the first case of ziconotide-induced dyskinesia. Ziconotide, a synthetic peptide analogue of the ω-conotoxin MVIIA that blocks selectively N-type voltage-sensitive calcium channels, has been used in intrathecal administration for 30 years. Ziconotide is a drug of choice for chronic pain because of its efficacy and flexibility because it can substitute or complement other intrathecal therapies including morphine or baclofen. Whereas substantial information is available regarding its efficacy, systematic data regarding the safety of ziconotide remain scant. The adverse reactions to ziconotide described so far regard only the coordination and execution of intentional movements.
  
  
  METHODS
  A 15-year-old male patient developed dyskinesia affecting the head and upper limbs 2 days after administration of ziconotide as an add-on therapy to an established regimen of treatment with baclofen. The strict temporal relationship between ziconotide administration and dyskinesia, together with the absence of any other clinical alteration, led to the hypothesis of a possible adverse drug reaction. Ziconotide was thus withdrawn, and the symptoms disappeared within 2 days.
  
  
  CONCLUSIONS
  An analysis of the signaling pathways of baclofen and ziconotide revealed a possible drug interaction that allowed ziconotide to trigger dyskinesia.
authors: From the *Scientific Institute IRCCS Eugenio Medea, Lecco; †AOU Anna Meyer Children's Hospital, Florence; and ‡Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences, L. Sacco, "Luigi Sacco" University Hospital, Università di Milano; §IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; and ∥Unit of Clinical Pharmacology, CNR Institute of Neuroscience, Department of Biomedical and Clinical Sciences, L. Sacco, "Luigi Sacco" University Hospital, Università di Milano, Milan, Italy.
authors: Marco
authors: M
authors: Pozzi
authors: Luigi
authors: L
authors: Piccinini
authors: Flavio
authors: F
authors: Giordano
authors: Carla
authors: C
authors: Carnovale
authors: Valentina
authors: V
authors: Perrone
authors: Paolo
authors: P
authors: Pellegrino
authors: Stefania
authors: S
authors: Antoniazzi
authors: Anna Carla
authors: AC
authors: Turconi
authors: Sonia
authors: S
authors: Radice
authors: Emilio
authors: E
authors: Clementi
mesh_terms: D000293:Adolescent; D001418:Baclofen / Q000008:administration & dosage / Q000009:adverse effects*; D002547:Cerebral Palsy / Q000175:diagnosis / Q000188:drug therapy*; D004338:Drug Combinations; D004409:Dyskinesia, Drug-Induced / Q000175:diagnosis*; D006801:Humans; D008297:Male; D020960:omega-Conotoxins / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D004338:Drug Combinations; D020960:omega-Conotoxins; C078452:ziconotide; D001418:Baclofen