Effects of nonionic monomeric and dimeric contrast media on the twitching reaction of the rat. Importance of osmolality and electrolyte content.
OBJECTIVE
The authors established a rat model of the twitching reaction to contrast media in striated muscle and investigated the influence of nonionic contrast medium on the twitching reaction regarding the nonionic dimer iodixanol compared with the monomer iohexol and the dimer iotrolan. The authors also studied the influences from the electrolyte additions of iodixanol.


METHODS
The interval from start of contrast medium injection to start of head movement was compared for iohexol (140 and 350 mg iodine/mL), iodixanol (150 and 320 mg iodine/mL), and iotrolan (300 mg iodine/mL). Comparison was made with mannitol and mannitol containing the same electrolyte concentrations as iodixanol (150 and 320 mg iodine/mL).


RESULTS
No differences in latency period were found between iohexol 140 mg iodine/mL (isotonic) and 350 mg iodine/mL (880 mOsm/kg). Iodixanol caused a lesser effect on the twitching reaction than the iohexol solutions and iotrolan. When the electrolytes of iodixanol were added to mannitol (300 mOsm/kg), there was a later onset of the twitching reaction than with electrolyte-free mannitol.


CONCLUSIONS
Differences in latency period caused by a change in osmolality were not found. The interval for a twitching reaction was longer with iodixanol than with iohexol, iotrolan, and iso-osmolar mannitol. The weak effect of the iodixanol solution was probably partially caused by the electrolyte content.
Bååth
L
L
Department of Diagnostic Radiology, University of Lund, Malmö General Hospital, Sweden.
Besjakov
J
J
Pettersson
G
G
D000818:Animals; D002122:Calcium Chloride / Q000032:analysis; D003287:Contrast Media / Q000009:adverse effects* / Q000032:analysis / Q000737:chemistry; D004409:Dyskinesia, Drug-Induced / Q000209:etiology*; D005260:Female; D006257:Head / Q000503:physiopathology; D007472:Iohexol / Q000009:adverse effects* / Q000032:analysis / Q000737:chemistry; D008297:Male; D008353:Mannitol / Q000737:chemistry / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects*; D009994:Osmolar Concentration; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D012965:Sodium Chloride / Q000032:analysis; D014283:Triiodobenzoic Acids / Q000009:adverse effects* / Q000032:analysis / Q000737:chemistry
D003287:Contrast Media; D014283:Triiodobenzoic Acids; C033300:iotrolan; D008353:Mannitol; D007472:Iohexol; D012965:Sodium Chloride; C044834:iodixanol; D002122:Calcium Chloride