Sorry, you need to enable JavaScript to visit this website.

DILANTIN® Extended Oral Capsules (phenytoin) Nonclinical Toxicology

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis [see Warnings and Precautions (5.9)]

In carcinogenicity studies, phenytoin was administered in the diet to mice (10, 25, or 45 mg/kg/day) and rats (25, 50, or 100 mg/kg/day) for 2 years. The incidences of hepatocellular tumors were increased in male and female mice at the highest dose. No increases in tumor incidence were observed in rats. The highest doses tested in these studies were associated with peak serum phenytoin levels below human therapeutic concentrations.

In carcinogenicity studies reported in the literature, phenytoin was administered in the diet for 2 years at doses up to 600 ppm (approximately 160 mg/kg/day) to mice and up to 2400 ppm (approximately 120 mg/kg/day) to rats. The incidences of hepatocellular tumors were increased in female mice at all but the lowest dose tested. No increases in tumor incidence were observed in rats.

Mutagenesis

Phenytoin was negative in the Ames test and in the in vitro clastogenicity assay in Chinese hamster ovary (CHO) cells.

In studies reported in the literature, phenytoin was negative in the in vitro mouse lymphoma assay and the in vivo micronucleus assay in mouse. Phenytoin was clastogenic in the in vitro sister chromatid exchange assay in CHO cells.

Fertility

Phenytoin has not been adequately assessed for effects on male or female fertility.

What's New

No Current Announcements.

Therapeutic Area

Contact Pfizer Medical

Report an Adverse Event
1-800-438-1985

Search

Please enter your search term(s) for DILANTIN® Extended Oral Capsules

Contact Pfizer

Need to report an Adverse Event, Side Effect or Product Quality Concern?

Contact Pfizer Safety to report an adverse event, side effect or concern about the quality of a Pfizer product: (800) 438-1985

You may also contact the U.S. Food and Drug Administration (FDA) directly to report adverse events or product quality concerns at 1-800-FDA-1088 or www.fda.gov/MedWatch

Have a Medical Question on a Pfizer Prescription Medicine?
Contact Pfizer Medical Information to speak with a professional regarding your medical question on a Pfizer prescription product: (800) 438-1985
Have a Question on a Pfizer Over-the-Counter Product?
For Pfizer Consumer Healthcare non-prescription or over-the-counter products such as Advil, Centrum, Nexium or Thermacare, call (800) 322-3129
Have a Question about Pfizer Clinical Trials?
If you are looking for information about Pfizer studies currently recruiting new patients in your area, you can begin your search on our website. For questions about a Pfizer Clinical Trial, call (800) 718-1021 or email [email protected]
Need Information on Pfizer’s Patient Assistance Programs?

Pfizer RxPathways® connects eligible patients, regardless of their insurance status, to a range of assistance programs that offer insurance support, co-pay help, and medicines for free or at a savings. For more information, please call (844) 989-7284 or visit www.PfizerRxPathways.com.

Eligible patients can register for valuable savings offers for nearly 40 brand name medications. Visit www.MyPfizerBrands.com for more information.