Fresh Lime Alone for Smoking Cessation (LIM)

• Number of Participants with Adverse Events on each group [ Time Frame: week 12 ] [ Designated as safety issue: Yes ]
  All adverse events related to the use of nicotine gum and fresh lime during the 12-week treatment were measured as number and percent of participants in each group.
• 7-day point prevalence abstinence (PAR) of lime and gum groups [ Time Frame: week 4 ] [ Designated as safety issue: No ]
  Point prevalence abstinence rate (PAR), which was defined as percentage of participants who were able to abstain from smoking any tobacco products during the preceding week, was evaluated at week 4, 8, 12 and 24.
• 7-day point prevalence abstinence (PAR) of lime and gum groups [ Time Frame: week 8 ] [ Designated as safety issue: No ]
  Point prevalence abstinence rate (PAR), which was defined as percentage of participants who were able to abstain from smoking any tobacco products during the preceding week, was evaluated at week 4, 8, 12 and 24.
• 7-day point prevalence abstinence (PAR) of lime and gum groups [ Time Frame: week 12 ] [ Designated as safety issue: No ]
  Point prevalence abstinence rate (PAR), which was defined as percentage of participants who were able to abstain from smoking any tobacco products during the preceding week, was evaluated at week 4, 8, 12 and 24.
• continuous abstinence rates of the lime and gum groups [ Time Frame: week 24 ] [ Designated as safety issue: No ]
  CAR from week 9 through week 24 of the study was defined as proportion of participants who self-reported having refrained from smoking any tobacco products and confirmed by exhaled CO concentration of 10 ppm or less at all previous measurement points between week 9 and week 24.
• intensity of craving using 100-mm VAS score [ Time Frame: week 2 ] [ Designated as safety issue: No ]
  Intensity of cravings after morning awakening among smokers in both groups were recorded on the day of clinic visits at week 2, 4, 8, 12, and 24 of the study using 100-mm visual analogue scale (VAS). Mean scores of those in the lime and gum groups was calculated and compared.
• intensity of craving using 100-mm VAS score [ Time Frame: week 4 ] [ Designated as safety issue: No ]
  Intensity of cravings after morning awakening among smokers in both groups were recorded on the day of clinic visits at week 2, 4, 8, 12, and 24 of the study using 100-mm visual analogue scale (VAS). Mean scores of those in the lime and gum groups was calculated and compared.
• intensity of craving using 100-mm VAS score [ Time Frame: week 8 ] [ Designated as safety issue: No ]
  Intensity of cravings after morning awakening among smokers in both groups were recorded on the day of clinic visits at week 2, 4, 8, 12, and 24 of the study using 100-mm visual analogue scale (VAS). Mean scores of those in the lime and gum groups was calculated and compared.
• intensity of craving using 100-mm VAS score [ Time Frame: week 12 ] [ Designated as safety issue: No ]
  Intensity of cravings after morning awakening among smokers in both groups were recorded on the day of clinic visits at week 2, 4, 8, 12, and 24 of the study using 100-mm visual analogue scale (VAS). Mean scores of those in the lime and gum groups was calculated and compared.
• intensity of craving using 100-mm VAS score [ Time Frame: week 24 ] [ Designated as safety issue: No ]
  Intensity of cravings after morning awakening among smokers in both groups were recorded on the day of clinic visits at week 2, 4, 8, 12, and 24 of the study using 100-mm visual analogue scale (VAS). Mean scores of those in the lime and gum groups was calculated and compared.

The purpose of this study is to determine whether fresh lime alone is effective for smoking cessation.

Smoking is the major preventable cause of chronic medical diseases and death worldwide. Significant efforts led by World Health Organization (WHO) and several countries have been made to help current smokers to quit, particularly in the developing countries, where their smoking rates continued to rise. Clinical practice guidelines were therefore developed to guide all healthcare personnel in those countries to provide treatment for smokers. However, despite that, only a small number of smokers were able to quit successfully. A large number of smokers who are poor and heavily addicted to nicotine remain and have no access to any effective smoking cessation aids. Although there are several effective medications available for smoking cessation nowadays, the high price of them completely keeps poor smokers away from using them. Alternative and cheaper smoking cessation aids are therefore necessary. During the past decade, certain herbal remedies have been introduced in smoking cessation in Thailand. One of them that have been used widely without any supporting evidence is the fresh lime (Citrus aurantifolia), the well-known native citrus to Southeast Asia. It is anecdotally claimed to be effective and safe in smoking cessation. The present study was designed to determine the efficacy and safety of fresh lime as a smoking cessation aid compared with those of nicotine gum.

• Experimental: Fresh lime
  Those who were randomly assigned to receive fresh lime were instructed to use it every time they began to crave cigarettes and as often as they needed. Fresh lime needed to be washed and cut into several small pieces by 1st cutting each lime into quarters and then each quarter further into 4 pieces. When needed, subjects were told to suck each piece of lime and thereafter chew the lime skin. To maintain freshness, the remaining slices were to be covered with plastic wrap and stored in the refrigerator as soon as possible. All participants in this group had to report the number of fresh lime slices used per day in the self-report card.
  Intervention: Other: Fresh lime
• Active Comparator: Nicotine gum
  The dosage of nicotine gum used in this group was primarily based on the participants' FTND scores. Those with FTND score of 4 or above were given 4-mg nicotine gum. The 2-mg gum was assigned only to light smokers. Appropriate gum use by "chew and park" technique was instructed to all subjects in this group. They were advised to use the gum whenever they began to crave a cigarette but not to exceed more than 20 pieces per day. All participants in this group also had to report the total number pieces of gum used per day in the self-report card. Like the lime use group, phone calls were also made every 2-3 days during the initial month of study to remind them of technique and record keeping.
  Intervention: Other: Fresh lime

• Rungruanghiranya S, Ekpanyaskul C, Hattapornsawan Y, Tundulawessa Y. Effect of nicotine polyestex gum on smoking cessation and quality of life. J Med Assoc Thai. 2008 Nov;91(11):1656-62.
• Lykkesfeldt J, Priemé H, Loft S, Poulsen HE. Effect of smoking cessation on plasma ascorbic acid concentration. BMJ. 1996 Jul 13;313(7049):91. No abstract available.
• Levin ED, Behm F, Carnahan E, LeClair R, Shipley R, Rose JE. Clinical trials using ascorbic acid aerosol to aid smoking cessation. Drug Alcohol Depend. 1993 Oct;33(3):211-23.

Inclusion Criteria:

• Age over 18
• Smoked regularly at least one year prior to study entry
• Had the desire to quit smoking
• Signed informed consent

Exclusion Criteria:

• Having current dental problems
• Active peptic ulcer disease
• Psychiatric disorders
• Citrus allergy
• Pregnancy
• Use of illicit drugs
• Participation in another clinical trial and/or using any first-line smoking cessation aids within the past 30 days