The interaction of aflatoxin B1 with vitamin K, phenylbutazone, and sulfamethoxine in rats.

The interactions of aflatoxin B1 (AFB1) with vitamin K, phenylbutazone, and sulfamethoxine were investigated in albino rats. Vitamin K (5 mg/kg) was able to completely suppress the increase in whole blood clotting time caused by AFB1 (25 micrograms/kg). Phenylbutazone (50 mg/kg) and sulfamethoxine (50 mg/kg) also significantly (P less than 0.05) lowered the increased clotting time caused by AFB1. Equilibrium dialysis was performed on rat plasma (4 mg/ml protein content) to investigate the displacement of AFB1 (3 micrograms) from its bound form by vitamin K (250 micrograms), phenylbutazone (2500 micrograms), and sulfamethoxine (2500 micrograms). Phenylbutazone and sulfamethoxine significantly (P less than 0.05) displaced AFB1 from rat plasma protein. Histopathological examinations performed on the liver, kidneys, and spleen of control and treated rats showed that none of the drugs used appeared to offer any significant organ protection against AFB1 except in the spleen.

The influence of furosemide on intrarenal distribution of 2-sulphanilamido-5-methoxypyrimidine in rats with normal and reduced renal parenchyma.

Internal distribution of 2-sulphanilamido-5-methoxypyrimidine (SM) 100 mg/kg in rats is characterized by a corticopapillary gradient. The papilla/cortex ratio of SM concentration averaged 2.25 +/- 0.34. Furosemide (5 mg/kg) elicited a significant corticopapillary gradient decrease for SM. Corticopapillary gradients for SM and sodium showed a positive correlation (r = 0.45; p less than 0.001). After furosemide corticopapillary gradient for SM averaged 1.4 +/- 0.22. Unilateral nephrectomy alone induced no significant difference in the corticopapillary gradient for SM compared with controls. Corticopapillary gradient for SM was significantly lower in unilaterally nephrectomized rats than in controls when furosemide was given after 24 hours or 7 or 14 days. The results suggest that SM concentration was significantly higher in the medulla than in the cortex; furosemide led to a significant decrease of corticopapillary gradient for SM against controls; the corticopapillary gradient for SM did not significantly change after unilateral nephrectomy; the effect of furosemide on corticopapillary gradient for SM was more pronounced in rats after unilateral nephrectomy than in controls.

[The influence of food on the bioavailability of drugs on the example of sulfamethoxydiazine (author's transl)]. / De Einfluss der Nahrung auf die Bioverfügbarkeit von Medikamenten am Beispiel des Sulfamethoxydiazin.

It is demonstrated that the bioavailability of sulfamethoxydiazine (Durenat), taken as an example, is much better when administered simultaneously with a test meal than when given in the fasting state. Also a high-lipid meal in comparison with a high-protein or high-carbohydrate meal considerably improves the bioavailability of sulfamethoxydiazone. Food as well as the composition of food are likely to have short-term and long-term consequences on absorption and biotransformation and therefore influence the bioavailability of drugs.

The effect of the composition of food on the absorption of sulfameter.

The present investigation is concerned with the influence of the composition of food on the absorption of sulfameter. Six physically healthy patients each were given 2 g of sulfameter simultaneously with a high lipid, high protein and high carbohydrate test meal. This experiment was designed as a threefold crossover study, and there was a randomized assignment of patients to the different conditions. The results show that sulfameter is significantly better absorbed when administered with a high lipid meal than when given with a high protein or high carbohydrate meal, demonstrated by the areas under the serum concentration curves (AUC), by the peak serum concentration and by the cumulative renal excretion.