None listed
Conditions
Brief summary
Smoking is the most significant cause of lost healthy life in New Zealand. Smoking cessation dramatically reduces the risk of smoking–related diseases such as cardiovascular disease and cancer and is thus a key strategy for reducing health inequalities. Medicines currently available in New Zealand to help people stop smoking, such as nicotine replacement therapy (NRT), bupropion, nortriptyline and varenicline, are not used by many smokers (at least 70% of whom want to quit) because of low acceptability, side effects, cost and contraindications. Cytisine, an alkaloid found in plants such as Golden Rain and the New Zealand Kowhai, may address some of these concerns. Cytisine is a partial agonist at the nicotinic acetylcholine receptor (nAChR) and is thought to act by attenuating unpleasant tobacco withdrawal symptoms while simultaneously making smoking less rewarding. It has been used in Central and Eastern Europe for several decades. Evidence from three placebo-controlled trials conducted several decades ago in Eastern Europe suggests that cytisine is effective. However, these trials reported limited safety data, and no other human data are available in the literature. With cytisine appearing promising as a smoking cessation aid, it is essential to obtain human pharmacokinetic, dose response and adverse effects data to inform future studies.
Interventions
Participants are provided with a 25 day supply of cytisine tablets. Each tablet contains 1.5mg of cytisine:
Dosing schedule by the oral route:
Days 1-3: 1 tablet every 2 hours through the waking day (up to six tablets per day)
Days 4-12: 1 tablet every 2.5 hours (up to 5 per day); designated Quit date is day 5
Days 13-16: 1 tablet every 3 hours (up to 4 per day)
Days 17-20: 1 tablet every 4-5 hours (3 per day)
Days 21-25: 1 tablet every 6 hours (2 per day)
Participants are observed over the 25
Participants are provided with a 25 day supply of cytisine tablets. Each tablet contains 1.5mg of cytisine: Dosing schedule by the oral route: Days 1-3: 1 tablet every 2 hours through the waking day (up to six tablets per day) Days 4-12: 1 tablet every 2.5 hours (up to 5 per day); designated Quit date is day 5 Days 13-16: 1 tablet every 3 hours (up to 4 per day) Days 17-20: 1 tablet every 4-5 hours (3 per day) Days 21-25: 1 tablet every 6 hours (2 per day) Participants are observed over the 25 days of cytisine intervention
Sponsors
University of Auckland
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Smokers They will be eligible for inclusion in the trial if: - they are at least 18 years of age, - they are able to provide written consent, - willing to attempt to quit smoking - are currently a regular smoker.
Exclusion criteria
-pregnant or breastfeeding, -current users of NRT products, -current users of non-NRT smoking cessation therapies (e.g. buproprion [registered tradename Zyban], clonidine, nortriptyline, or varenicline [registered tradename Champix]), -enrolled in another smoking cessation programme -have had a heart attack, stroke, or severe angina within the previous two weeks, -have uncontrolled high blood pressure (> 150 mmHg systolic, > 100 mmHg diastolic), -have phaeochromocytoma, -suffer from schizophrenia. -have severe renal impairment -have had an adverse reaction to varenicline or cytisine
Outcome results
None listed