Fosinopril-Hydrochlorothiazide

Reproductive studies and long-term carcinogenicity studies with fosinopril sodium and hydrochlorothiazide have not been conducted. The combination of fosinopril and hydrochlorothiazide was not mutagenic in the Ames microbial mutagen test, the mouse lymphoma forward mutation assay, or the Chinese hamster ovary cell cytogenetic assay. The combination was also not genotoxic in a mouse micronucleus test in vivo.

Fosinopril Sodium

No evidence of a carcinogenicity was found when fosinopril was given in the diet to rats and mice for up to 24 months at doses up to 400 mg/kg/day. On a body weight basis, the highest dose was about 250 times the maximum human dose of 80 mg, given to a 50 kg subject. On a body surface area basis, this dose is 20 (mice) to 40 (rats) times the maximum human dose.

Neither fosinopril nor the fosinoprilat moiety was mutagenic in the Ames microbial mutagen test, the mouse lymphoma forward mutation assay, or a mitotic gene conversion assay. Fosinopril was also not genotoxic in a mouse micronucleus test in vivo and a mouse bone marrow cytogenetic assay in vivo.

In Chinese hamster ovary cell cytogenetic assay, fosinopril increased the frequency of chromosomal aberrations when tested without metabolic activation at a concentration that was toxic to the cells. However, there was no increase in chromosomal aberrations at lower drug concentrations without metabolic activation or at any concentration with metabolic activation.

There were no adverse reproductive effects in male and female rats treated with up to 60 mg/kg daily. At doses 4 times higher, slight increases in pairing time were seen. This higher dose is about 125 (body surface area basis) or 600 (body-weight basis) times greater than the dose received by a 50 kg human receiving 20 mg a day.

Hydrochlorothiazide

Under the auspices of the National Toxicology Program, rats and mice received hydrochlorothiazide for two years at doses up to 100 (rats) and 600 (mice) mg/kg/day. On a body weight basis, these highest doses were about 2400 times (mice) or 400 times (rats) the fosinopril sodium and hydrochlorothiazide dose of 12.5 mg, given to a 50 kg subject. On a body surface area basis, these doses are 226 times (mice) and 82 times (rats) the fosinopril sodium and hydrochlorothiazide dose. These studies uncovered no evidence of carcinogenicity in rats or female mice, but there was equivocal evidence of hepatocarcinogenicity in male mice.

Hydrochlorothiazide was not genotoxic in in vitro assays using strains TA 98, TA 100, TA 1535, TA 1537, and TA 1538 of Salmonella typhimurium (Ames assay); in the Chinese Hamster Ovary (CHO) test for chromosomal aberrations; or in in vivo assays using mouse germinal cell chromosomes; Chinese Hamster bone-marrow chromosomes, and the Drosophila sex-linked recessive lethal trait gene. Using concentrations of hydrochlorothiazide of 43 to 1300 mg/mL, positive test results were obtained in the in vitro CHO Sister Chromatid Exchange (clastogenicity) test and in the Mouse Lymphoma Cell (mutagenicity) assays. Using an unspecified concentration of hydrochlorothiazide, positive test results were also obtained in the Aspergillus nidulans nondisjunction assay.

No adverse effects upon fertility were seen when rats and mice received dietary hydrochlorothiazide prior to mating and throughout gestation at doses up to 4 (rats) and 100 (mice) mg/kg/day. These doses are from 3.2 (body surface area basis in rats) to 400 (weight basis in mice) times greater than the dose received by a 50 kg human receiving 12.5 mg a day.