US – Pfizer is pausing distribution of its anti-smoking treatment, Chantix, after finding elevated levels of cancer-causing agents called nitrosamines in the pills.

The drug which had already been approved by the U.S drug regulator owing to the fact that it has accepted levels of N-nitrosodimethylamine (NDMA), a carcinogenic organic compound, was recalled by its manufacturer Pfizer.

Chantix was approved by the Food and Drug Association (FDA) in May 2006 as a prescription medication which, along with support, helps adults aged 18 and over quit smoking and is used for 12 to 24 weeks.

The drug was among the top two most used medication for patients who were on remission from smoking, the other popular drug is Zyban (Bupropion).

Bupropion is a prescription anti-depressant medication marketed under the brand names Wellbutrin (for depression) and Zyban (for smoking cessation).

Zyban does not contain nicotine and is thought to affect chemicals in the brain that are related to nicotine craving.

The drug can be used either alone or in conjunction with nicotine replacement therapy.

This drug has shown to be approximately twice as effective as placebo at three months, and approximately 1.5 times as effective as placebo at 1 year with studies showing a success rate of about 30% in three months and 15% within a year.

This is however not the case for long term success rates as smokers tend to relapse after longer time periods.

Chantix, however, was developed solely to help people quit smoking and it works by interfering with nicotine receptors in the brain.

Its success rate has been shown to be approximately three times as effective as placebo at both three months and 1 year with studies showing that at 3 months, 44% of those using Chantix were able to quit smoking.

The withdrawal of chantix by Pfizer sees the company exit from global smoking cessation market estimated to achieve a value of US$63.99 billion by 2026 growing at a CAGR of 16.9% between 2018 to 2026.

Global revenue from the drug fell by 17% to $919 million in 2020 as COVID-19 curbs hampered demand and the company lost patent protection in the United States in November.