Nutrition, age and drug metabolism

Nutritional consequences of drugs used in pediatrics

Pediatric drugs may have significant nutritional consequences via their effects on appetite, nutrient absorption, nutrient metabolism, and nutrient excretion. Examples of common drugs and effects on nutrition include the inhibition of vitamin C storage by aspirin; impairment of folic acid utilization by phenobarbital; phenylalanine accumulation by trimethoprim; and lipolysis caused by caffeine. Nutritional consequences of drugs are of greater clinical significance in children who are malnourished and in those on drugs for prolonged periods. It is important that physicians consider possible deleterious consequences of drugs in making therapeutic choices.

The B-vitamin group and the activity of hepatic microsomal mixed-function oxidases of the growing Wistar rat

1. Male Wistar rats were given isoenergetic, semi-synthetic diets deficient in thiamin, riboflavin, pyridoxine or all the B-vitamins. 2. In rats given these deficient diets the 'sleeping time' induced with pentobarbital (PB) and the 'paralysis time' with zoxazolamine (Zz) were prolonged. 3. The tolerance effect against both drugs was nearly independent of the levels of B-vitamins in the diets. 4. In preparations from vitamin-B deficient animals the activities of the following hepatic microsomal enzymes were reduced: the aliphatic hydroxylase of PB, the aromatic hydroxylases of aniline (EC 1.14.14.1) and of Zz, the N-demethylase of aminopyrine, the UDP glucuronyltransferase (EC 2.4.1.17) of p-nitrophenol. The reactions most influenced were those of 'type-1' substrates, particularly those involving the hydroxylases. 5. The effects observed were caused mainly by deficiency of riboflavin and to a lesser extent of thiamin or pyridoxine.