medwireNews: More individuals quit smoking cigarettes using electronic cigarettes (ECs) than using nicotine chewing gum, but rates are similar compared with an oral nicotine receptor partial agonist, according to a randomized trial published in JAMA Internal Medicine.
The trial comprised 1068 people in China who smoked at least 10 cigarettes a day who were assigned to receive one of the three treatments with minimal behavioral support for 12 weeks. At 6 months, 15.7% of 409 individuals using ECs had sustained abstinence from smoking, compared with 14.2% of 409 people using the nicotine receptor partial agonist varenicline, and 8.8% of 250 people using nicotine gum.
“The quit rate in the EC arm was noninferior to the varenicline arm,” note trial investigator Zhao Liu (China-Japan Friendship Hospital, Beijing, China) and colleagues. The absolute risk reduction with EC versus varenicline was a nonsignificant 1.47 percentage points, whereas the odds of sustained abstinence was a significant 92% higher with EC than nicotine gum.
Smoking abstinence was defined as a self-report of smoking no more than five cigarettes from 2 weeks after the target quit date (normally within 2 weeks of baseline) and no smoking in the week preceding the final assessment, validated by an expired-air carbon monoxide (CO) reading of less than 8 parts per million.
Liu and colleagues highlight that 7-day point-prevalence CO levels at 6 months were also lower in the EC group, at 30.3% versus 27.9% and 18.4% in the varenicline and NRT arms, respectively.
For the trial, the researchers assigned participants at seven Chinese hospitals to receive a nicotine salt-based EC (30 mg/mL for 2 weeks; 50 mg/mL thereafter), nicotine gum (2 mg for those smoking ≤20 cigarettes per day; 4 mg for >20 cigarettes per day), or varenicline (0.5 mg/day for 3 days; 0.5 mg twice daily for 4 days; then 1 mg twice daily thereafter). The mean age of the cohort was 33.9 years and 66.5% were men.
On average, participants smoked 16 cigarettes per day at the start of the trial and had been smoking for around 13 years.
Despite similar adherence in all treatment groups during the first 3 months, 63% of participants in the EC group continued to use the intervention during months 3–6, and the investigators say that “further studies are needed to assess whether such use is beneficial or harmful. None of the participants continued varenicline or nicotine gum use beyond 3 months.
The proportion of patients reporting at least one adverse reaction was similar across the three groups, at 9% of those in the EC arm, and 10% each in the varenicline and NRT arms. The most common reactions among those using ECs and NRT were throat irritation (7.8 and 8.0%, respectively) and mouth irritation (6.9 and 8.8%), while nausea (8.8%) was the most frequent among those taking varenicline. There were no serious adverse events.
In a linked editorial on the research, Dorothy Hatsukami (University of Minnesota, Minneapolis, USA) and Judith Prochaska (Stanford University, California, USA) note that only a single form of NRT was used as a comparator and suggest that the dose of nicotine gum used in the trial may have been suboptimal. Yet they agree that the study “contributes to the accumulating evidence that ECs can be effective in helping people quit smoking.” They also highlight the existing wide accessibility of ECs as consumer products.
Hatsukami and Prochaska observe that no ECs are currently FDA approved as smoking cessation aids. They comment that one potential drawback of ECs is “the greater addiction potential relative to the FDA-approved cessation medications,” with the possibility that “people who smoke may be transferring one nicotine addiction for another.”
However, they point out that EC use is associated with “significantly lower exposures to carcinogens and other toxicants” than smoking, stating that “switching completely to ECs is very likely a safer alternative.”
The editorialists conclude: “For adults who formerly smoked cigarettes and who now are exclusively using ECs, clinicians should provide encouragement that they have taken an important step to protect their health.”
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JAMA Intern Med 2024; doi:10.1001/jamainternmed.2023.7846
JAMA Intern Med 2024; doi:10.1001/jamainternmed.2023.7855