The developmental toxicity of three antimicrobial agents observed only in nonroutine animal studies

Effects of moxifloxacin and clinafloxacin on murine limb buds cultured in regular and in magnesium-deficient medium

Evaluation of the prenatal toxicity of a substance in rats or other animals according to the current guidelines is often hampered by the rapid metabolism of the test compound and/or by maternal toxicity. One example for such a compound is moxifloxacin. In vitro systems offer the possibility to study the direct effects of the test compound on embryonic tissues. The aim of this study was to evaluate the embryotoxic potential of moxifloxacin in vitro using the murine limb bud culture. Clinafloxacin, which was found to be teratogenic when tested in rats, was used for comparison. The effects of various concentrations of moxifloxacin (10, 30, 60 and 100 mg/L) and clinafloxacin (3, 10 and 30 mg/L) on growth and differentiation of 12-day-old murine limb buds were studied in a standard and in a magnesium-deficient medium. After termination of the culture, the respective front limb buds were examined by different methods. Clinafloxacin showed clear-cut effects at a concentration of 30 mg/L in both media. Effects were similarly pronounced as the effects observed with moxifloxacin at a concentration of 100 mg/L. Lower concentrations of moxifloxacin, which are achieved during therapy in humans, did not impair growth and differentiation of limb buds. Using electron microscopy, slight ultrastructural changes could be seen after exposure to 3 mg clinafloxacin/L medium. Ultrastructurally, clinafloxacin caused a concentration-dependent decrease of the extracellular matrix, swelling of cell organelles and at higher concentrations necrotic chondrocytes. These effects were significantly enhanced in a magnesium-deficient medium. In conclusion, the effects of moxifloxacin on murine limb buds in vitro were definitely less pronounced than those of clinafloxacin. Effects on growth and differentiation occurred with moxifloxacin only at concentrations that are higher than plasma concentrations observed during therapy. This result is of special interest, because due to rapid metabolism of moxifloxacin in rats results from a routinely performed segment II type study cannot be used for a risk assessment.

Urinary tract infections in unplanned pregnancies and fetal outcome

AIM

Many pregnant women are exposed to antibiotics for urinary tract infections during pregnancy. Our aim is to bring attention to antibiotherapy in unplanned pregnancies.

METHOD

Among the 511 cases followed by our 'Toxicology Information and Follow-up Service' for drug exposure during pregnancy, 101 cases, unaware of their pregnancy, had been prescribed antibiotics and urinary antiseptic drugs in the first trimester of their unplanned pregnancies. The data on the outcome of these pregnancies and the babies were evaluated in this study.

RESULTS

Of the 511 cases, 101 pregnant women were exposed to nine kinds of drugs. Seventy-five cases had healthy babies; two had babies with major malformations; one had a baby with congenital hypothyroidism; five had spontaneous abortions; and eight cases underwent induced abortions. The outcomes of eight pregnancies are unknown. Two pregnancies are still continuing without any problem. One baby had a fetal renal anomaly; however, the physical examination did not reveal any other malformations. The baby died 4 hours after delivery. Another baby had atrial septal defect, a major malformation, and one baby had congenital hypothyroidism.

CONCLUSION

Urinary tract infection is one of the most frequently seen complications of pregnancy. Our study indicated that the possibility of pregnancy should be considered when prescribing antibiotics for urinary tract infections in women of reproductive age.

Temporal effect of methyl parathion on ovarian compensatory hypertrophy, follicular dynamics and estrous cycle in hemicastrated albino rats

Methyl parathion, an organophosphorus pesticide, was administered i.p. at a dose of 5 mg/kg body weight to hemicastrated virgin rats for 1, 5, 10 and 15 days. Treatment with methyl parathion for 1 and 5 days revealed no change in the ovarian weight with -0.64% and -9.63% hypertrophy respectively and no change in healthy and atretic follicles when compared with hemicastrated oil-treated controls. However, treatment with methyl parathion for 10 and 15 days resulted in a significant decrease in ovarian weight gain with -21.36% and -31.98% hypertrophy, respectively, a significant decrease in the number of healthy follicles, and no change in the number of atretic follicles. The number of estrous cycles and duration of each phase of the estrous cycle were significantly affected with methyl parathion treatment for 5, 10 and 15 days. However, there were no significant changes in the number of estrous cycles and duration of estrus and metestrus phases in 1 day methyl parathion treatment except for a decrease and increase in proestrus and diestrus phases respectively. The weight of the uterus was significantly decreased whereas those of the liver, kidney and adrenal did not change in any of the methyl parathion treated groups.