Is Guaiacum sanctum Effective Against Arthritis?
An Ethnobotany Case

Part III—Human Study

Working with a local clinic, Dr. Tonoany and Ms. Geilke selected 20 individuals with severe arthritis from a set of volunteers to participate in a double blind study. All volunteers were severely crippled with arthritis, no longer found indomethacin an effective arthritis treatment, and were between the ages of 60 and 65. Fifteen were females and five were males. All volunteers were screened to ensure normal blood pressure, urinalysis, and erythrocyte levels, and all had the highest degree of complications due to arthritic joint swelling.

Half of the subjects were given Guaiacum resin at 400 mg/kg and half were given a placebo. Neither the doctor nor the patient knew who was receiving the resin and who was receiving the placebo. After one month, in addition to monitoring blood pressure, urine, and erythrocyte levels, x-rays of the most arthritic joint were examined and the degree of arthritic complications was categorized as A, B, C, or D, with D being the greatest degree of complications due to swelling of the joint.

Questions

1. What did the clinical study show?
2. Are the side effects a problem? Why or why not?
3. What are the limitations of the experimental design?
4. Dr. Tonany has found that “probably fewer than 100 trees remain in Costa Rica, most in the Palo Verde Nature Preserve.” What ecological concerns does this experiment raise?
5. Based on these results, what should Dr. Tonoany and her colleagues do next?
6. Is it realistic to test an unknown drug on humans after a single clinical trial?
7. (Ethics question:) If it looks like this drug is potentially medically useful, should the native peoples be compensated for their trees and the information that led to the experiment?

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