Loperamide Therapy for Acute Diarrhea in Children: Systematic Review and Meta-Analysis

Background: Loperamide is widely used in adults for acute diarrhea. However, its use in children has been discouraged by the World Health Organization and the American Academy of Pediatrics owing to concerns over safety and efficacy in young children. Methods and Findings: To assess the efficacy and adverse effects of loperamide compared with placebo for acute diarrhea in children, we reviewed Medline, EMBase, the Cochrane Central Register of Controlled Trials, and bibliographies of known clinical trials and of review articles, and we also interviewed key investigators in the field. We undertook a systematic review and meta-analysis of randomized controlled trials of children younger than 12 y of age with acute diarrhea, comparing loperamide with placebo. Included trials reported data on diarrhea duration or severity, or provided data on adverse effects. Compared with patients who received placebo, patients allocated to loperamide were less likely to continue to have diarrhea at 24 h (prevalence ratio 0.66, 95% confidence interval [CI]: 0.57 to 0.78), had a shorter duration of diarrhea by 0.8 d (95% CI: 0.7 to 0.9 d), and had a lower count of stools at 24 h (0.84, 95% CI: 0.77 to 0.92). Results were similar when random-effects summaries were estimated. Serious adverse events, defined as ileus, lethargy, or death, were reported in eight out of 927 children allocated to loperamide (0.9%, 95% CI: 0.4% to 1.7%). Serious adverse events were not reported in any of the 764 children allocated to placebo (0%, 95% CI: 0% to 0.5%). Among the children allocated to loperamide, serious adverse events were reported only among children younger than 3 y. Conclusions: In children who are younger than 3 y, malnourished, moderately or severely dehydrated, systemically ill, or have bloody diarrhea, adverse events outweigh benefits even at doses ≤0.25 mg/kg/d. In children who are older than 3 y with no/minimal dehydration, loperamide may be a useful adjunct to oral rehydration and early refeeding. In seriously ill children under 3 years of age with diarrhea the adverse effects of loperamide outweighed the benefits, but the drug could be useful as part of treatment for other children. Background.: While diarrhea is often thought of as a mild, inconvenient condition, it is estimated that, worldwide, 1.6–2.5 million children under 5 y old die each year from diarrhea, most of them in developing countries. Dehydration is the key factor in the deaths of these children. In richer countries, diarrhea is rarely deadly, but it has been calculated that, in the United States, the annual national health-care cost associated with the condition amounts to around US$1.5 billion. Some of the cost results from the purchase of anti-diarrheal drugs. Loperamide is one of the most widely used of these drugs. In most countries, it can be obtained without a prescription. The use of loperamide is intended to reduce the frequency of bowel movements, but taking it will not lead to rehydration, nor will it kill the infectious organisms responsible for the condition. Why Was This Study Done?: The World Health Organization and other health authorities have concerns that loperamide may not be effective in young children and that it may not be safe. In the United States, the Food and Drug Administration approves its use for children older than 2 y of age. The researchers wanted to know whether loperamide could play a useful part in treating diarrhea in children. What Did the Researchers Do and Find?: They did not do any new work with children suffering from diarrhea. Instead, they searched the medical literature for previously conducted trials involving the use of loperamide. They used these previously conducted trials to estimate whether use of loperamide influenced the duration of diarrhea or the number of diarrheal stools in children under 12 y of age. They also used these trials to examine adverse effects of loperamide. In total they found 13 studies that met the criteria they had set for inclusion in their study. More than 900 children in these studies had been given loperamide for their diarrhea; each trial also had a control group of children whose treatment did not include loperamide. Most of the children in the studies had only mild diarrhea. The researchers found that, compared with children in the control groups, those treated with loperamide were less likely to continue to have diarrhea 24 h later, had a shorter duration of diarrhea, and had a lower count of diarrheal stools. However, eight of the children given loperamide and none of the control group did have serious adverse effects. All those who had serious adverse effects were less than 3 y of age. What Do These Findings Mean?: The researchers concluded that if a child is less than 3 y of age, malnourished, moderately or severely dehydrated, or has bloody diarrhea, the risk of adverse events from loperamide treatment outweighs the benefits, even at low doses. In other children, loperamide may be a useful part of treatment. However, they advise that rehydrating the child (by giving fluids orally) and progressively returning him or her to a normal diet should still be the main focus in the treatment of childhood diarrhea. Additional Information.: Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040098.