Investigation of Kava Effects on NNK Metabolism

Inclusion Criteria:

- Adult ≥ 18 years

- Current smoker of ≥ 5 cigarettes daily, determined by self-report

- Adequate liver and kidney function, defined as:

- Bilirubin, alkaline phosphatase, ALT, and AST within normal limits

- Creatinine <1.2

- Adequate hemoglobin, defined as a hemoglobin ≥12 mg/dL for men and ≥11 for women.

- Ability and willingness to abstain from all medication and dietary supplements for 3
days prior to kava administration, continuing until a minimum of 7 days after kava
administration. Topical medications and inhaled medications that do not contain
steroids are permitted.

- Ability and willingness to completely abstain from alcohol consumption for 3 days
prior to kava administration, continuing until a minimum of 7 days after kava
administration

- Ability to understand the investigational nature of the study and provide informed
consent

- Willingness to take kava supplement as instructed

Exclusion Criteria:

- Known hepatobiliary disease or impairment

- History of gastric bypass surgery, gastric banding, bowel resection, malabsorption
syndromes such as celiac sprue or pancreatic insufficiency, or other conditions that
may affect the absorption of kava

- Chronic medication use that cannot be safely stopped

- Use of tobacco products other than cigarettes (i.e. snuff, snuz, smokeless tobacco,
cigars, pipes)

- Major or chronic medical medical disease, including heart disease, poorly controlled
diabetes, etc., to be adjudicated by the principal investigator

- Women who are pregnant, intend to become pregnant within 3 months of the study period,
or who are breastfeeding

- Current or recent (within 12 months) problems with drug use or alcohol dependence by
self-report

- Antibiotic use within 2 months of study enrollment by self-report

- Alcohol dependence, abuse, or history of dependence/abuse by self-report