Healthcare, UK (Commonwealth Union) – A recent study led by the University College London (UCL) researchers suggests that the interruption in the supply of a prescription medication crucial for smoking cessation may have significant consequences in England. Varenicline, commonly known as Champix, is renowned for its effectiveness in aiding smokers to quit by curbing nicotine cravings and alleviating withdrawal symptoms. However, its distribution halted in July 2021 across the UK and Europe due to concerns regarding elevated levels of a potentially harmful substance found in the tablets.
Published in the journal Addiction and supported by Cancer Research UK, this study analyzed survey responses and NHS prescription data to gauge the impact of the drug’s decline in England. The findings revealed a stark drop in varenicline usage, plummeting from 3.9% of all quit attempts in the latter half of 2021 to nil by the close of 2022.
Extrapolating from this data, the researchers estimated that approximately 85,800 individuals forewent varenicline over the course of a year. Consequently, due to smokers resorting to less effective cessation aids or forgoing medication and nicotine replacement altogether, an estimated 4,200 fewer individuals successfully quit smoking annually. Projections indicate that this shortfall could result in 1,890 additional smoking-related deaths per year in the absence of varenicline, extending over subsequent decades. Lifelong smokers are expected to lose an average of over 10 years of life compared to non-smokers, underscoring the gravity of the situation.
The lead author Dr Sarah Jackson, for the UCL Tobacco & Alcohol Research Group, says “Varenicline is a gold-standard prescription treatment for smokers trying to quit. The disruption of its supply in the UK and Europe likely reduced the number of people successfully stopping smoking, which will lead to more preventable deaths. Our study gives a sense of the scale of this.
“Fortunately, another prescription drug called cytisine became available in the UK in January that is similarly effective to varenicline and could help fill the gap. Efforts to promote awareness of cytisine among smokers and prescribers may help to reduce smoking deaths over the long term.”
According to data from the Smoking Toolkit Study, a monthly survey of 1,700 representative adults in England, the use of varenicline in quit attempts decreased to 0.8% in the latter half of 2022, and there were no attempts using varenicline in the last quarter of the year.
Concurrently, information gathered from GP surgeries in England indicated that varenicline made up only 0.1% of smoking cessation prescriptions in December 2022.
While some individuals turned to bupropion or NRT as alternatives, these options are estimated to be approximately 40% less effective than varenicline for aiding cessation.
The data revealed a doubling in prescriptions for bupropion between July 2021 and December 2022. However, there was also a 35% decline in monthly prescriptions for smoking cessation medications overall when comparing the periods of June 2018 to June 2021 and July 2021 to December 2022.
As a result, the researchers estimated that around 35% of potential varenicline users would opt for no medication at all to aid cessation, while the remaining 65% would use bupropion or NRT.
Pfizer, the manufacturer of varenicline, halted its distribution due to an elevated level of potentially carcinogenic nitrosamines found in the tablets. In response to actions taken by regulators in the UK and EU, healthcare providers in the UK were advised to return batches of the medication in October 2021. While generic versions of the drug are accessible in the US, Canada, and Australia, they remain unavailable in the UK.
Researchers of the study pointed out that Nitrosamines, which can heighten cancer risks with prolonged exposure, are also found in tobacco products. They also highlighted that if the nitrosamines in the tablets were comparably carcinogenic to tobacco-specific nitrosamines, a typical 12-week course of Champix (varenicline) would deliver an equivalent dose to smoking 198 cigarettes (roughly 18 days of smoking at an average rate of 11 cigarettes per day). Despite this, the risk level remains notably lower than persisting with long-term smoking habits.
The Senior author Professor Lion Shahab, of the UCL Tobacco & Alcohol Research Group, says “The withdrawal of varenicline has had substantial unintended consequences. Our study suggests it will lead to thousands more avoidable deaths from smoking in England alone.
