Lactulose in the management of constipation: a current review.

To review the current published clinical studies evaluating the clinical efficacy and safety of lactulose compared with other laxatives or placebo. Adverse effects associated with lactulose are also reported. Information was retrieved by searching the MEDLINE and EMBASE databases for clinical trials, abstracts, conference proceedings, and review articles dealing with lactulose. Emphasis was placed on clinical trials where lactulose was compared with other laxatives or placebo in patient populations where the diagnosis of constipation was reasonably established. The methodology and results from clinical studies were evaluated. Assessment of the studies was made based on diagnosis of constipation, prior management of patients, follow-up of patients, dosage, and adverse effects. Clinical trials in geriatric patients, terminally ill patients, children, and normal and constipated subjects were reviewed. In most instances, lactulose was compared with a placebo, without incorporating the current education on dietary techniques for improving defecation. Generally, clinical trials have demonstrated a beneficial response compared with placebo, although sometimes that response has been only marginally better, from a clinical point of view.