BACKGROUND:Syrup of ipecac is one of the better-known, long-standing medicinal herbs. It comes from Psychotria ipecacuanha, although several other scientific names have been used for this plant. Along with quinine and curare, those living in South America's rainforests were familiar with its powerful effects.
European explorers brought ipecac home with them, first mentioning it in 1648. One French physician gave it to King Louis XIV’s son who recovered completely from dysentery. The physician was rewarded with the sole licence to sell ipecac root, and became a very rich man.
During the 18th century, ipecac was studied carefully and found to be an expectorant (causing coughing of sputum) at low doses and an emetic (causing vomiting) at higher doses.
Ipecac became an important treatment for dysentery, but it worked well in some patients and not others. Investigating this showed that some dysentery was caused by amoebae and other cases by bacteria. Only amoebic dysentery is cured by ipecac. However, the treatment also caused serious adverse effects, including vomiting, nerve damage and heart problems.
Once other treatments for amoebic dysentery were developed in the 1950s, syrup of ipecac became primarily an emetic and expectorant. In 1983, the American Academy of Pediatrics recommended that all homes contain a small bottle of ipecac syrup available in case of poisonings.
In recent decades, use of syrup of ipecac has declined. A position paper published by US poison control centres in 2005 concluded that ipecac should be used only in the rarest of circumstances.
EVIDENCE FROM STUDIES
The active ingredient in ipecac is emetine, an alkaloid identified in 1817. It irritates the digestive tract leading to coughing which develops into vomiting if the dose is sufficiently large.
The 2005 research review found that 80-85 per cent of people vomit after one dose of ipecac syrup and almost everyone else will vomit after a second dose. However, animal studies found that the amount of food or drug vomited up varied considerably. In some animals, less than 5 per cent of the drug given was recovered from the vomit.
Several studies gave volunteers a drug and measured blood levels to see how much was absorbed. Ipecac was given at different times following the drug. In general, the amount of drug absorbed was reduced significantly only if ipecac was given within 30 minutes of it, and preferably much sooner.
Very little research has examined whether ipecac reduces hospital admission rates or the direct effects of poisons. A few studies reviewed charts of poison victims and found that those given syrup of ipecac did not fare any better than those who didn’t receive it. In one study, the group with the worst outcomes were those given ipecac and charcoal.
PROBLEMATIC ASPECTS
Long-term use or large doses of ipecae can cause excessive irritation leading to damage of the digestive tract, heart problems, breathing difficulties and convulsions. Ipecac has been used by people with anorexia nervosa or bulimia with numerous serious adverse effects. Cases of sudden death due to heart failure have occurred.
RECOMMENDATIONS
Ipecac was a herbal remedy trusted for many years. It caused vomiting and was assumed to be beneficial after poisonings. However, syrup of ipecac exemplifies where a measurable outcome (getting sick) does not necessarily indicate clinical benefit (reducing the poison’s damaging effects). Activated charcoal and other methods used by poison control centres are more effective.
Syrup of ipecac should not be taken for any of its traditional uses. Effective alternatives are readily available. Ipecac has served humanity well in history, but because of its adverse effects, it is best to leave this one in the past.
Dónal O’Mathúna has a PhD in pharmacy, researching herbal remedies, and an MA in bioethics, and is a senior lecturer in the School of Nursing, Dublin City University
