Comparison of the toxicities of two iron formulations in a swine model.
OBJECTIVE
To describe the histopathologic and pharmacokinetic differences of acute iron poisoning between chewable multivitamins with iron and solid iron tablets in a swine model.


METHODS
This was a prospective, randomized, unblinded toxicity study of iron poisoning of two iron formulations in male Yorkshire pigs. Eight swine were randomized to receive 60 mg/kg of iron in either solid iron tablets or chewable multivitamins with iron. Serum iron, arterial blood gases, and episodes of vomiting were recorded over a ten-hour period. Routine histologic evaluations of the esophagus, stomach, small intestine, large intestine, and liver were performed immediately after the study period. Pharmacokinetic analyses of area under the concentration-time curve (AUC), time to peak concentration, and peak serum iron concentration were performed.


RESULTS
There was no significant difference between the serum iron levels except at three and four hours. There was a significant higher AUC in the chewable group compared with the solid group. Pathologic evaluation identified severe esophageal inflammation and focal erosion in the solid iron tablet group in two of the four animals, compared with no focal erosions and minimal esophageal inflammation in the chewable group. No significant change was identified in the liver, small intestine, or large intestine in either group.


CONCLUSIONS
These results demonstrate increased local gastrointestinal toxicity following a large ingestion of solid iron tablets in a swine model, compared with chewable multivitamins with iron. Higher serum iron levels were identified in the animals that received chewable multivitamins with iron.
Nordt
S P
SP
California Poison Control System-San Diego Division, USA. snordt@ucsd.edu
Williams
S R
SR
Behling
C
C
Richter
P
P
Manoguerra
A S
AS
Clark
R F
RF
D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D002626:Chemistry, Pharmaceutical; D004195:Disease Models, Animal; D058085:Iron Compounds / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D008297:Male; D009061:Mouth Mucosa / Q000187:drug effects / Q000473:pathology*; D011446:Prospective Studies; D012016:Reference Values; D013552:Swine; D014815:Vitamins / Q000008:administration & dosage
D058085:Iron Compounds; D014815:Vitamins