NEW DRUGS FOR OLD PROBLEMS: CONSTIPATION AND POLYETHYLENE GLYCOL

Key words: Constipation, Polyethylene glycol

Drugs which are commonly used to soften the stools include mineral oils and osmotic laxatives. While the former are not recommended in paediatric patients, the latter, such as lactulose and lactitol, which are equivalent, must be given at significantly higher dosage than recommended by Italian manufacturers and their effect is at least partially due to modification of bacterial flora. Polyethylene glycols (PEG) are molecules of diverse weight which cannot be absorbed nor metabolized. PEG (either PEG 3350 or PEG 4000), at the concentration of 7.1 percent keeps the accompanying water in the intestine without any further drawing in of water from the intestinal wall, thus avoiding the risk of dehydration. High volumes of PEG can be used for complete intestinal lavage, as for colonoscopy, or for treating severe foecal impaction. Low volumes, on average 1 g/kg/die, i.e.15 ml/kg/die solution to be increased or reduced depending on effect, are effective in the great majority of cases for treating chronic constipation. In PEG products manufactured in Italy salts give an unpleasant flavour which is not present in a product recently marketed in the US, which contains only pure PEG.