Effects of daily intake of zidovudine-stavudine on rat pregnancy outcome: biological essay

PURPOSE

To evaluate the effects at term of a highly active antiretroviral drug association when administered for the whole period of rat pregnancy.

METHODS

Forty pregnant rats weighing about 200 g were randomly divided into four groups: a control group (Ctr = drug vehicle control, n=10) and three experimental groups, which were treated with an oral solution of zidovudine-stavudine (Explx = 10/1 mg/kg b.w., n=10; Exp3x = 30/3 mg/kg b.w., n=10; Exp9x = 90/9 mg/kg b.w., n=10) from "day 0" up to the 20th day of pregnancy. Maternal body weights were recorded at the start of the experiment and on the 7th, 14th and 20th day thereafter. At term (20th day) the rats were anesthetized and submitted to hysterotomy. Implantations, reabsorptions, living fetuses, placentae and intrauterine deaths were looked for and recorded. The collected fetuses and placentae were weighed and the concepts were examined by a stereoscopic microscope looking for external malformations.

RESULTS

No significant alterations due to the antiretroviral drug treatment could be detected regarding the number of implantations, fetuses, placentae, absorptions and malformations nor regarding maternal and fetal mortality.

CONCLUSIONS

Administration of the association zidovudine/stavudine for the whole period of rat pregnancy did not interfere with the maternal, fetal and placental weight gain as well as abnormalities detectable by the employed methodology.

Chronic action of association of zidovudine, lamivudine and ritonavir on pregnant rats. A biologic assay

PURPOSE

To evaluate at term the effects of a highly active antiretroviral (HAAR) drug association administered during the entire period of rat pregnancy.

METHODS

Three groups (n = 10 each) of adult pregnant rats were treated with an oral solution of HAAR (Exp 1 = 10/5/20 mg/kg b.w.; Exp 2 = 30/15/60 mg/kg b.w.; Exp 3 = 90/45/180 mg/kg b.w.) from day "0" up to the 20th day of pregnancy. A fourth group served as a control. At term (20th day) the rats were killed under deep anesthesia and the number of implantations, resorptions, living fetuses, placentae and intrauterine deaths were recorded.

RESULTS

The highest HAAR doses caused lower maternal weight gain, lower litter weights, and lower placental weights compared to the control group.

CONCLUSIONS

HAAR during the entire period of rat pregnancy can reduce maternal body weight gain and lower term placental weight.

Effects of the association zidovudine plus ritonavir on the liver and kidneys of pregnant rats. Morphological and biochemical aspects

PURPOSE

To evaluate biochemical and morphological effects on rats submitted to three different doses of the association zidovudine and ritonavir administered throughout pregnancy.

METHODS

Forty pregnant EPM-1 Wistar rats weighing about 200 g were randomly divided into the control group (Ctr = drug vehicle control, n = 10) and three experimental ones which were treated with an oral solution of zidovudine/ritonavir (Exp1 = 10/20 mg/kg bw, n = 10; Exp2 = 30/60 mg/kg bw, n = 10; Exp3 = 90/180 mg/kg bw, n = 10) from 'day 0' up to the 20th day of pregnancy. At term (20th day) the rats were anesthetized. Blood and fetal and maternal organ samples (livers and kidneys) were taken for morphological and biochemical analyses.

RESULTS

Upon histological examinations fetal livers and kidneys appeared normal. In contrast the maternal samples revealed structural alterations. Maternal kidneys of the three experimental groups exhibited progressive and dose-dependent histological alterations; liver alterations were detected only in Exp3. Blood levels of AST and ALT were not significantly different from the control group but urea and creatinine levels were lower in groups Exp3 and Exp1.

CONCLUSIONS

The administration of zidovudine plus ritonavir throughout rat pregnancy can cause morphological as well as functional changes in maternal kidneys.

Extended administration of the association of zidovudine plus ritonavir during rat pregnancy: maternal and fetal effects

The purpose of the study was to evaluate at term, the effects of the association of zidovudine/ritonavir administered during the entire period of rat pregnancy. Forty pregnant EPM-1 Wistar rats were divided randomly into four groups: one control (drug vehicle control, n=10) and three experimental treated with an oral solution of zidovudine/ritonavir (Exp 1 = 10/20 mg/kg bw, n = 10; Exp 2 = 30/60 mg/kg bw, n=10; Exp 3 = 90/180 mg/kg bw, n=10) from day 0 up to day 20 of pregnancy. Maternal body weights were recorded at the start of the experiment and at the 7th, 14th and the 20th day thereafter. At term (20th day) the rats were anesthetized and, upon laparotomy and hysterotomy, the number of implantations, resorptions, living fetuses, placentae and intrauterine deaths were recorded. The collected fetuses and placentae were weighed, and the concepts were examined under a stereoscopic microscope for external malformations. The maternal body gain and the mean fetal weight at term were both significantly lower (p < 0.01 and p < 0.0001, respectively) in the experimental groups compared to the control. The recorded resorptions were higher in Exp 2 and Exp 3 groups than in the control group. The other parameters were not affected. The exposure of pregnant rats at term to a 1:2 association of zidovudine plus ritonavir resulted in a significant reduction in maternal body weight gain and increased rate of fetal resorption.