Know Cancer

forgot password

St. John's Wort for Tobacco Cessation

Phase 2
18 Years
Not Enrolling
Smoking, Nicotine Dependence

Thank you

Trial Information

St. John's Wort for Tobacco Cessation

Cigarette smoking is the single most important preventable cause of morbidity, mortality and
excess health care costs in the United States. The prevalence of cigarette smoking among
U.S. adults has declined from 42% in 1965 to 20.9% in 2004. However, the overall decline is
not occurring at a rate that will meet national health objectives by 2010. Available
pharmacotherapies for the treatment of tobacco dependence are not efficacious for all
tobacco users and have an overall estimated efficacy of approximately 20% for long-term
tobacco cessation. Thus, novel pharmacotherapies for tobacco cessation need to be explored.

Current smokers tend to be younger with less education and belong to a lower socioeconomic
status. Tobacco cessation treatments are expensive and often not covered by Medicare,
Medicaid, or third party-payers. Our goal is to evaluate novel, safe, acceptable, effective,
and inexpensive therapies that will increase tobacco abstinence rates.

The United States Public Health Service (USPHS) guideline recommends nicotine replacement
therapy and bupropion as first-line agents for the treatment of tobacco dependence.
Bupropion acts by central dopamine and norepinephrine reuptake inhibition. St. John's Wort
(SJW), a widely used herbal product to treat mild to moderate depression, shares a similar
mechanism of action and is available as a tobacco cessation aid in a number of
over-the-counter preparations. While currently approved pharmacotherapies for tobacco
dependence cost between $120-$240 per month, SJW is relatively inexpensive ($15 per month)
and is well-tolerated. At present, no randomized prospective study of St. John's Wort for
tobacco cessation has been published.

We plan to test the efficacy of SJW for tobacco cessation in a randomized, double-blind,
placebo-controlled, three-arm, parallel group, dose-ranging clinical trial. We will obtain
preliminary data about the efficacy of two different oral doses of SJW for improving tobacco
abstinence rates and decreasing symptoms of nicotine withdrawal. All subjects will receive
a behavioral intervention during participation in the study. A total of 120 subjects will
be recruited into the study and randomly allocated to one of the three groups (groups A, B,
and C). Participants in group A will receive SJW 300-mg three times a day for twelve weeks
while participants in group B will receive SJW 600-mg three times a day for twelve weeks.
Participants in group C will receive a matching placebo for the same duration.

We will conduct this research through the Nicotine Research Program (NRP) at the Mayo Clinic
in Rochester, Minnesota. We are uniquely situated for completing this research as more than
7,500 patients have been enrolled in over 75 clinical trials conducted through the NRP. We
propose the following specific aims:

Primary Aims:

1. To obtain preliminary evidence of the effect of a 12-week course of SJW in two different
oral doses of 300-mg three times a day or 600-mg three times a day compared to placebo on
the 7-day point prevalence tobacco abstinence rates at end of treatment and six months in
120 smokers.

Hypothesis: Cigarette smokers who receive SJW in two different oral doses of 300-mg three
times a day or 600-mg three times a day for 12 weeks will have higher 7-day point prevalence
tobacco abstinence rates at end of treatment and six months compared to cigarette smokers
receiving placebo.

Secondary Aim:

1. To obtain preliminary estimates of the effect of a 12-week course of SJW in two
different oral doses of 300-mg three times a day or 600-mg three times a day compared to
placebo on prolonged tobacco abstinence rates at six months.

Hypothesis: Cigarette smokers who receive SJW in two different oral doses of 300-mg three
times a day or 600-mg three times a day for 12-weeks will have higher prolonged tobacco
abstinence rates at six months compared to cigarette smokers receiving placebo.

This study is innovative in that we are testing a novel therapeutic agent for the treatment
of tobacco use. At the completion of this study, we expect to have obtained preliminary
evidence regarding the effect of two different doses of SJW on symptoms of nicotine
withdrawal and tobacco abstinence. We will also collect information on adverse effects of
SJW in tobacco users and obtain data to plan a larger Phase III clinical trial, if the
results from this trial suggest a potential for efficacy.

Inclusion Criteria

A total of 120 subjects will be recruited in the study. Subjects will be eligible to
participate if they:

1. Are at least 18 years of age;

2. Smoked more than10 cigarettes/day for the past one year;

3. Willing to make a quit attempt;

4. Able to participate fully in all aspects of the study; and

5. Have been provided with, understand, and have signed the informed consent.

Individuals will be excluded from study participation if they:

1. Meet diagnostic criteria for current major depressive disorder or lifetime history of
bipolar disorder or schizophrenia. Patients with mild or moderate depressive
symptoms [Beck Depression Inventory, Second Edition ≤ 28], but who do not meet
current diagnostic criteria for major depressive disorder, will be included;

2. Are currently (within past 30 days) using antipsychotics or antidepressants;

3. Are currently (in previous 30 days) using any treatments for tobacco dependence
(i.e., behavioral therapy, nicotine replacement therapy, bupropion SR, clonidine, or

4. Have used an investigational drug within the 30 days prior to enrolling in this

5. Have ever used an herbal product for tobacco cessation;

6. Have recent history (in the past 3 months) of alcohol abuse or dependence as assessed
by the CAGE questionnaire and study investigators;

7. Have a recent history of drug abuse as assessed by the Drug Abuse Screening Test 20
(DAST-20) and physician interview;

8. Are pregnant, lactating, or of child bearing potential, likely to become pregnant
during the medication phase and not willing to use a reliable form of contraception.
Reliable forms of contraception include barrier (diaphragm or condom with spermicidal
jelly), injections, intrauterine device [IUD], surgical sterilization and abstinence;

9. Have a history of any major cardiovascular events in the past 6 months including
unstable angina, acute MI or coronary angioplasty;

10. Have clinically significant acute or chronic progressive or unstable neurologic,
hepatic, renal, cardiovascular, respiratory or metabolic disease;

11. Are currently on medications interacting with St. John?s Wort including warfarin,
antiretrovirals (particularly indinavir and nevirapine), cyclosporine and tacrolimus,
digoxin, nifedipine and verapamil, theophylline, all serotonergic drugs (serotonin
reuptake inhibitors, tricyclic antidepressants, tramadol, venlafaxine, tryptophan and
buspirone), MAO inhibitors, oral contraceptives, anti-cancer agents including
imatinib and irinotecan, migraine medications (sumatriptan and zolmitriptan),
methadone, lithium, sibutramine, atorvastatin and simvastatin, midazolam, alprazolam,
fexofenadine, omeprazole, and general anesthetics (fentanyl, propofol, and

12. Have another household member or relative participating in the study;

13. Have a known allergy to St. John?s Wort;

14. Have a history of photosensitivity;

15. Are professional drivers or operators of heavy machinery; and

16. Are scheduled for a planned surgical procedure within five days of taking SJW.

Type of Study:


Study Design:

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Outcome Measure:

Biochemically Confirmed 7-day Point Prevalence Abstinence From Tobacco

Outcome Description:

Point prevalence tobacco abstinence was adjudicated if the following conditions were met:(a) self-reported tobacco abstinence for the previous 7 days with a negative response to the question "Have you used any type of tobacco,even a puff, in the past 7 days?" and (b) Expired Carbon Monoxide equal or less then 8 parts per million.

Outcome Time Frame:

12 weeks following start of medication

Safety Issue:


Principal Investigator

Amit Sood, M.D., MSc

Investigator Role:

Principal Investigator

Investigator Affiliation:

Mayo Clinic


United States: Food and Drug Administration

Study ID:




Start Date:

September 2005

Completion Date:

March 2008

Related Keywords:

  • Smoking
  • Nicotine Dependence
  • Tobacco Use Disorder
  • Smoking



Mayo Clinic Rochester, Minnesota  55905