Ivermectin is a powerful anti-parasitic drug that may be used in children to treat both internal and external infestations. It is easy to administer and effectively clears most parasites with a single dose. Ivermectin is usually safe to use in humans but some concerns have been raised over its use in children under 5 years of age or weighing less than 15 kg.
Parasites
Parasites are organisms that live on a host species, such as humans, causing a variety of diseases. External or exoparasites live on our skin and include lice, mites, ticks and fleas, while internal or endoparasites live inside our bodies and include worms and larvae. Parasites rarely cause death, as it is not in their interests to kill their host, but they can make existing disease conditions much worse. For healthy children, parasites such as head lice or hookworm are often just an inconvenience, while in sick or malnourished children parasites such as intestinal worms may mean the difference between life and death.
Ivermectin
Ivermectin is a anti-parasitic drug known to kill over 120 species of internal parasites and 190 species of external parasites. It is produced by an organism called Streptomyces avermitilis found in soil. It was originally developed for the veterinary market with over 5 billion animal doses distributed worldwide, but more recently ivermectin has been used in 50 million humans. The drug is absorbed through skin but it can also be given orally in liquid or pill form or by injection.
Once it has been administered Ivermectin passes into the blood and circulates through the body. It is taken up by parasites while they are feeding and passes into their brain and nervous system, causing paralysis and death. The body's natural defense systems can then clear away the dead parasites. In humans, ivermectin cannot usually cross from the blood to the brain, making it a safe drug to use.
Use in children
Ivermectin can be used to treat resistant cases of head lice and scabies. It is rarely used for first time treatments and is not available in any over-the-counter preparations but must be prescribed by a health-care provider.
Ivermectin is mainly used to treat tropical disease in children who are part of the poorest populations on our planet. These children, some of the "bottom billion," have parasites that cause disabilities such as onchoceriasis, better known as river blindness, or filariasis, which blocks the lymph ducts causing swelling and deformity of the limbs. It has been estimated that all of these children have at least one severe parasitic illness. Parasites increase the disease load of sick children and contribute to high rates of infant mortality. Those that cause disability will affect a child's ability to learn and work, making it harder for them and their families to escape the cycle of starvation and poverty. Ivermectin can be used to treat whole communities and dramatically change lives.
Side effects
The side effects of Ivermectin are related to depression of the nervous system. These are seen particularly in young or low body weight children who have not developed a sufficient barrier at the brain to stop the drug diffusing out of the blood and into the cells of the nervous system. Ivermectin should not be given to children under 5 years of age, under 15kg body-weight or to mothers who are breast-feeding infants.
At normal doses the side effects include vomiting, rapid heart beats, sleepiness, dilated pupils and changes in blood pressure. In some children that have been given a relative overdose, the ability to breathe has been compromised, leading to death.
Many of the side effects seen following administration of ivermectin can be related to the death and breakdown of large numbers of parasites in the child's body, which may provoke an allergic reaction. In severe cases of internal parasitism, other drugs may be given at the same time to prevent these reactions.
The future
Ivermectin can make a huge difference to the lives of many impoverished children, and several international initiatives exist to donate doses of the drug to communities in Africa and South America. Drug companies have led the way in providing free ivermectin, but now charitable organizations are seeking funds to continue this work. Freeing children from the effects of parasitic disease may help to reduce the additional aid required to relieve their plight and give them a secure and happy future.
References
- "Treatment of 18 children with scabies or cutaneous larva migrans using ivermectin"; del Mar Sáez-De-Ocariz M, McKinster CD, Orozco-Covarrubias L, Tamayo-Sánchez L, Ruiz-Maldonado R; Clin Exp Dermatol. 2002 Jun;27(4):264-7
- "The greatest breakthrough: IVOMEC"
- "Rescuing the bottom billion through control of neglected tropical diseases"; Prof Peter J Hotez MD, Prof Alan Fenwick PhD, Lorenzo Savioli MD, Prof David H Molyneux PhD; The Lancet, Vol. 373 No. 9674 pp 1570-1575 May 2009
