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Study Information
Study Attribute Value
CEBS Accession Number: 002-02737-0001-0000-2
Chemical Name: Promethazine hydrochloride
CASRN: 58-33-3
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 641980_SCE
Study Result: Equivocal

Study Result: Equivocal
Activation Trial Trial Call
No Activation  1  Negative 
Induced Rat Liver S9  1_S9  Questionable 

Trial #: 1    Activation: No Activation    Date: 05/05/1982    Trial Call: Negative   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Water 
0         
 50 1051 489 0.465 9.78 26.0 0.000
Test Chemical Promethazine hydrochloride 
 0.5       
 50 1047 444 0.424 8.88 26.0 -8.856 
1.6       
 50 1050 412 0.392 8.24 26.0 -15.666 
5         
 50 1043 400 0.384 8.00 26.0 -17.573
Positive Control Mitomycin-C 
 0.005     
 50 1050 1174 1.118 23.48 26.0 140.310
Trend: -3.111        
Probability: 0.999        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 04/29/1982    Trial Call: Questionable   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Water 
0         
 100 2093 1023 0.489 10.23 26.0 0.000
Test Chemical Promethazine hydrochloride 
5         
 50 1045 561 0.537 11.22 26.0 9.835 
16         
 50 1049 570 0.543 11.40 26.0 11.171 
50         
 50 1046 606 0.579 12.12 26.0 18.532
Positive Control Cyclophosphamide 
1         
 100 2086 1492 0.715 14.92 26.0 46.335
Trend: 3.366        
Probability: 0.000