By Rosman Ahmad
The Sun, October 31, 1995
IRON IS A FUNDAMENTAL MINERAL that is required by the body to produce red blood cells. With iron, these cells would be able to carry oxygen effectively in the human body.
Normally, about 70% of body iron is functional or "essential" iron and 30% storage or "non-essential" iron. In women, the stored iron tends to be less than half of that in men. Inadequate intake of iron may result in iron-deficiency anaemia or reduction in blood quantity.
In the United States, there are an estimated 120 iron-related products marketed nationwide. Locally, there are about 40 such products in the market and they are mostly in combination with other vitamins or mineral supplements.
Iron supplements should be taken according to the dosing instructions indicated on the label, or as advised by the doctor. Most iron preparations include one of the three ferrous salts: sulfate, fumarate or gluconate. Such preparations usually contain 15-18mg of elemental iron per dose for children and 60-90mg of elemental iron per dose for adult.
The types of iron products involved in injuries to children may vary and in most instances are related to products meant for pregnant women, which are highly potent.
Even though the amount of iron in other products such as multi-vitamins and mineral products is lesser, it is still dangerous to young children if they swallow enough of these products.
In most cases, toddlers may get hold of tablets left within their reach, in uncapped or loosely capped containers, while young children may be able to open the container. Iron is a corrosive agent. Excessive ingestion can damage the stomach and small intestine. It will also affect blood circulation which can damage the liver and other organs.
This may cause shock and can be fatal. Ingesting 200-400mg of iron can seriously injure children. This dose is equivalent to 14-17 tablets of children's vitamin and mineral supplements with iron, or four to seven tablets of a typical adults' iron supplement.
The lowest reported lethal dose for children was 600mg. However, ingesting more than 40mg of elemental iron per kilogram body weight is considered potentially serious and more than 60mg of elemental iron per kilogram body weight, potentially lethal.
Usually, the manifestations of iron poisoning are illustrated in four stages:
Stage 1: Shortly after ingestion, the patient will experience nausea, vomiting, explosive diarrhoea (usually bloody), colic, abdominal pain and upper gastrointestinal (GI) haemorrhage.
This is due to direct corrosive effect of iron to the intestinal mucosa. A patient may not experience any GI symptoms within the first six hours of ingestion if it is not a serious toxic ingestion.
However, there have been cases reported of severe shock, coma and death without GI symptoms. After six hours, severe overdose will lead to shock, coma and even death as a result of massive fluid and blood loss.
Stage 2: This stage starts as early as three to four hours from the time iron is ingested and it may last for up to 48 hours. Those who survive this phase may experience a latent period of apparent improvement over 12 hours.
Stage 3: Within 12-48 hours after ingestion, there may be worsening of the GI haemorrhage, severe lethargy or coma, shock, heart failure and a severe metabolic acidosis. Signs of liver damage may become evident with jaundice, hypoglycemia and coagulation defects. A patient may also demonstrate renal insufficiency secondary to poor perfusion and it may hinder chelation and elimination of the iron complex.
Stage 4: If the victim survives, scarring from the initial corrosive injury may result in pyloric stricture or other intestinal obstruction. Late sequelae may occur approximately two to six weeks after the initial ingestion. Hepatic damage and cirrhosis are well described with chronic iron ingestion.
Iron poisonings need immediate medical attention. Parents are advised to contact the doctor or poison center immediately should they suspect their child has accidentally ingested iron-containing medicine even if their children do not show any symptoms.
Below is the list of things that should be observed when using iron-containing tablets.
- Stored iron medication in a safe place.
- Do not put it next to children supplement containers since it may confuse the child.
- Make sure the packages are not left open or within reach of children. Secure child-resistant closures properly.
- Keep unit-dose packaged products in original containers.
- Store products out of children's reach.
- Seek immediate medical attention if a child accidentally swallows the product.
The writer is a Science Officer at the National Poison Centre, Universiti Sains Malaysia, Penang
