Reactions 1210 - 12 Jul 2008

★ SOctreotide

First report of parkinsonism and ataxia: case reportA 36-year-old woman developed parkinsonism and ataxia

while receiving octreotide.After being diagnosed with carcinoid syndrome at age

31 years, the woman was initiated on IM octreotide 20mgevery 4 weeks; the dose gradually increasing to 40mg every3 weeks. Three years later, the dose was increased to 30mgevery 2 weeks, including an additional SC octreotide 6–8mgper month. Two years later, she presented with a 1-yearhistory of leg cramps, plantar inversion and first toe extension.She also had impaired bilateral hand dexterity and overallslowness. There was a tendency to bump into things and leanto the left when walking, especially when tired or afterexercising. Her voice was also impaired. She was experiencingmild left limb dysmetria, hypokinesia, rigidity, and decreasedleft arm swinging when walking. There was symmetrichyperreflexia and stocking-glove numbness.

The octreotide dose was reduced to 20mg every 2 weeks,and after starting treatment with cetirizine, the octreotide dosewas further decreased to 10mg every 2 weeks. The woman’sclumsiness, slowness and fatigue improved. When octreotide30mg biweekly was reinstated, the slowness and clumsinessreturned. A subsequent dose reduction led to resolution. Hersymptoms had peaked approximately 1 year after reaching a70mg per month cumulative dose of octreotide, and had lasted1.5 years, until dose reduction.

Author comment: "We speculate that the octreotide-induced parkinsonism may have resulted fromoverstimulation of somatostatin receptors. . . The mechanismfor the associated limb dysmetria may have been mediatedby the direct somatostatin toxicity of cerebellar Purkinje cells".Espay AJ. Reversible parkinsonism and ataxia associated with high-doseoctreotide. Neurology 70: 2345-2346, No. 24, Part 1, 10 Jun 2008 -USA 801116882

» Editorial comment: A search of AdisBase, Medline andEmbase did not reveal any previous case reports ofparkinsonism or ataxia associated with octreotide. The WHOAdverse Drug Reactions database contained two reports ofataxia, but did not contain any reports of parkinsonism,associated with octreotide.

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Reactions 12 Jul 2008 No. 12100114-9954/10/1210-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved