Correspondence

The Disappearing Arsenal of Antiparasitic Drugs

N Engl J Med 2000; 343:1273-1274October 26, 2000

Article

To the Editor:

Parasitic infections remain scourges to people worldwide.1 Increasing international travel and immigration from countries where parasitic infections are endemic ensure that clinicians in the United States will be required to treat patients with these infections. Although safe and inexpensive treatments are available for most of these infections,2 there are few incentives for the pharmaceutical industry to make these drugs available in the United States.

In the past 10 years, several drugs — quinacrine, the most effective medication for giardia infection; niclosamide, the main treatment for tapeworm infection; and diethylcarbamazine, the best treatment for lymphatic filariasis — have been withdrawn from the U.S. market. Diloxanide, perhaps the best drug to eradicate gastrointestinal passage of amebic cysts, was formerly distributed by the Centers for Disease Control and Prevention (CDC), but it too is no longer commercially available. Intravenous quinine, the standard treatment for severe malaria in most of the world, was distributed by the CDC until 1991. At that time, quinidine was recommended for the intravenous treatment of severe malaria, because of its widespread availability as a treatment for arrhythmias.3 However, safer and more effective antiarrhythmic drugs have since become available, and quinidine is now no longer routinely available. Furthermore, halofantrine, an important treatment for chloroquine-resistant malaria, was approved by the Food and Drug Administration but was never marketed in the United States. Most recently, in June 2000, praziquantel was withdrawn from the U.S. market. This left no available treatment for imported cases of schistosomiasis, other fluke infections, or many tapeworm infections. The manufacturer subsequently agreed to resume distribution later this year, largely as a public service.

The problem remains that our health care system discourages the development and continued distribution of drugs for parasitic infections in the United States. It is paradoxical that, despite the high level of expenditure on health care in the United States, we have less access to effective and inexpensive antiparasitic drugs than do people in many developing countries. Furthermore, even in countries where there are many cases of parasitic infection, the continued production of antiparasitic drugs is often not secure.4 For example, despite the ongoing epidemic of trypanosomiasis in Africa, eflornithine, the only drug for arsenical-resistant central nervous system disease, is no longer being manufactured.

A. Clinton White, Jr., M.D.
Baylor College of Medicine, Houston, TX 77030

4 References

1. 1

   Crompton DW. How much human helminthiasis is there in the world? J Parasitol 1999;85:397-403
   CrossRef | Web of Science | Medline

2. 2

   Liu LX, Weller PF. Antiparasitic drugs. N Engl J Med 1996;334:1178-1184
   Full Text | Web of Science | Medline

3. 3

   Treatment with quinidine gluconate of persons with severe Plasmodium falciparum infection: discontinuation of parenteral quinine from CDC Drug ServiceMMWR Morb Mortal Wkly Rep 1991;40:21-23
   Medline

4. 4

   Pecoul B, Chirac P, Trouiller P, Pinel J. Access to essential drugs in poor countries: a lost battle? JAMA 1999;281:361-367
   CrossRef | Web of Science | Medline

Citing Articles (3)

Citing Articles

1. 1

   Vanessa R Anderson, Monique P Curran. (2007) Nitazoxanide. Drugs 67:13, 1947-1967
   CrossRef

2. 2

   A Clinton White Jr. (2004) Nitazoxanide: a new broad spectrum antiparasitic agent. Expert Review of Anti-infective Therapy 2:1, 43-49
   CrossRef

3. 3

   &NA;. (2000) News in brief.... Inpharma Weekly &NA;:1262, 5
   CrossRef