Pau D’arco

Common names: Lapacho, Taheebo

Botanical names: Tabebuia avellanedae, Tabebuia impestiginosa

Parts used and where grown

Various related species of pau d’arco trees grow in rain forests throughout Latin America. The bark is used for medical purposes.

Pau d’arco has been used in connection with the following conditions (refer to the individual health concern for complete information):

Science Ratings

Health Concerns

Infection

Prostatitis

Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars

Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star

For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Historical or traditional use (may or may not be supported by scientific studies)

Native peoples in Central and South America reportedly use pau d’arco bark to treat cancer, lupus, infectious diseases, wounds, and many other health conditions.¹ Caribbean folk healers use the leaf of this tree in addition to the bark for the treatment of backache, toothache, sexually transmitted diseases, and as an aphrodisiac.

Active constituents

Lapachol and beta-lapachone (known collectively as naphthaquinones) are two primary active compounds in pau d’arco. According to laboratory tests, both have anti-fungal properties as potent as ketoconazole, a common antifungal drug.² However, amounts of these constituents needed to exert an antifungal effect may be toxic to humans. Although these compounds also have anticancer properties according to test tube studies, the effective amount for this effect may also be toxic.³ ⁴ Therefore, pau d’arco cannot currently be recommended as a treatment for cancer.

How much is usually taken?

A traditional recommendation is 2–3 teaspoons (10–15 grams) of the inner bark simmered in a pint (500 ml) of water for fifteen minutes three times per day.⁵ However, the naphthaquinones believed to give pau d’arco its major effects are very poorly extracted in water, so teas are not usually recommended in modern herbal medicine.⁶ Capsules or tablets providing 500–600 mg of powdered bark can be taken three times per day. A tincture, 1/8–1/4 teaspoon (0.5–1 ml) three times per day, can also be used.

Are there any side effects or interactions?

High amounts (several grams daily over several days) of lapachol can cause uncontrolled bleeding, nausea, and vomiting.⁷ Use of the whole bark is typically safer than isolated lapachol—side effects have included nausea and gastrointestinal upset.⁸ Pregnant or breast-feeding women should avoid use of pau d’arco.

One case report exists of a 28-year-old man who died of liver failure after taking unspecified amounts of pau d’arco, scullcap, and zinc.⁹ It appears likely that this may have been a case of adulteration of scullcap with germander.¹⁰

At the time of writing, there were no well-known drug interactions with pau d’arco.

References
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1. Duke JA. CRC Handbook of Medicinal Herbs. Boca Raton, FL: CRC Press, 1985, 470–1.

2. Guiraud P, Steiman R, Campos-Takaki GM, et al. Comparison of antibacterial and antifungal activities of lapachol and beta-lapachone. Planta Med 1994;60:373–4.

3. Tyler VE. Herbs of Choice: The Therapeutic Use of Phytomedicinals. Binghamton, NY: Pharmaceutical Products Press, 1994, 180.

4. Oswald EH. Lapacho. Br J Phytother 1993/4;3:112–7.

5. Foster S. Herbs for Your Health. Loveland, CO: Interweave Press, 1996, 70–1.

6. Awang DVC, Dawson BA, Ethier JC, et al. Naphthoquinone constituents of commercial lapacho/pau d’arco/taheebo products. J Herbs Spices Med Plants 1994;2:27–43.

7. Duke JA. CRC Handbook of Medicinal Herbs. Boca Raton, FL: CRC Press, 1985, 470–1.

8. Oswald EH. Lapacho. Br J Phytother 1993/4;3:112–7.

9. Hullar TE, Sapers BL, Ridker PM, et al. Herbal toxicity and fatal hepatic failure [letter]. Am J Med 1999;106:267–8.

10. Brown D. A case of fatal liver failure associated with herbal products. Healthnotes Rev Complement Integrative Med 1999;6:176–7.

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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires March 2007.