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nosed hepatotoxicity (Cases #1–9) and 6 cases of suspected or probable hepatotoxicity (Cases #10–15). The cases are arranged in order of apparent severity with the most severe case, which required a liver transplant, presented as Case #1. Many of these patients ingested chaparral in capsule or tablet form (Cases #1–3, 5–11). Most of the chaparral products were unidentified as to whether they contained dried plant material or extracts. The listed amount of chaparral ingested ranged from 0.3 to 6 g/day; however, this information was not included in all case reports. The duration of chaparral use (which is not indicated in 2 of the cases) ranged from 20 days to “many years.” It is notable that Case #15 was the only patient known to use chaparral tea: 4 bags daily for 1.5 years. The product used by this patient was examined using microscopic and chromatographic analysis and was correctly identified as Larrea tridentata with no evidence of biochemical or biological contamination (Sheikh et al., 1997). The severity of the liver damage in these case reports does not seem to correlate directly with either the amount of chaparral consumed or the duration of use. There are five cases with documented recovery from liver damage after cessation of chaparral use (Cases #2, 5, 8, 9, 10). There is one case (#8) documenting a return of jaundice following resumption of chaparral ingestion.

Table C-2 summarizes the clinical case reports of patients who took chaparral in combination with other supplements or ingredients, primarily other botanicals. The six cases of hepatotoxicity found in Table C-2 are difficult to evaluate because of the confounding factor of possible adverse effects due to these other substances. These cases include well-documented hepatotoxicity (Cases #17–20) but the cause of the liver damage is difficult to interpret. Two cases returned to normal after cessation of chaparral (Cases #18, 22). There are also reports (Cases #25–29 and Series A) of subjects taking an aqueous alcoholic extract (90 percent ethanol) as 8 to 10 percent of a formula with other herbs, ingesting a total of 30 to 240 mL over a period of 40 days to 5 months, with no indication of liver damage according to liver function tests.

Adverse event reports to Special Nutrition/Adverse Event Monitoring System (SN/AEMS): Table D presents the available information on cases reported in the SN/AEMS. The 18 reports include 12 cases indicating varying degrees of liver damage. (These 12 cases are included among the patients in Table C-1.) It should be noted that in the SN/AEMS reports there is no indication of whether a causal relationship exists between the adverse event and chaparral ingestion.

3. Interactions

There are no known interactions with chaparral.

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