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[tak-uh-fi-lak-sis] /ˌtæk ə fɪˈlæk sɪs/
Medicine/Medical. immediate, temporary immunization against the effects of injection of a toxic extract owing to previous small injections of the same extract.
a decreased response to a medicine given over a period of time so that larger doses are required to produce the same response.
Also, tachyphylaxia
[tak-uh-fi-lak-see-uh] /ˌtæk ə fɪˈlæk si ə/ (Show IPA)
Origin of tachyphylaxis
tachy- + Greek phýlaxis a guarding, equivalent to phylak- (stem of phylássein to guard) + -sis -sis
Related forms
[tak-uh-fi-lak-tik] /ˌtæk ə fɪˈlæk tɪk/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for tachyphylactic


very rapid development of tolerance or immunity to the effects of a drug
Word Origin
New Latin, from tachy- + phylaxis on the model of prophylaxis. See prophylactic
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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tachyphylactic in Medicine

tachyphylaxis tach·y·phy·lax·is (tāk'ə-fĭ-lāk'sĭs)

  1. Rapid desensitization to a pharmacologically or physiologically active substance produced by inoculation with a series of small doses.

  2. A rapidly decreasing response to a drug following its initial administration.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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