Champix(varenicline) : Submission of written requests once again to the MHLW and Pfizer Japan urging more adequate revisions of the package insert
2009-12-28
Champix is widely used in Japan as an aid to smoking cessation treatment.
However, a significant number of neuropsychiatric symptoms have been observed, including changes in behavior, agitation, depressed moods, suicidal thoughts, and suicidal behavior.
Nevertheless, these harmful events were not written in the warning section of the Japanese Prescription Information.
On the other hand, the information excessively suggests that these symptoms may have resulted from the smoking cessation itself.
Therefore, on July 6th 2009, we submitted a written request to the Ministry of Health, Labour and Welfare (MHLW) and Pfizer Japan to revise the package insert, to make a comprehensive effort to improve methods of assessing and monitoring the risks associated with drugs and biological products as per the US Food and Drug Administration (FDA), and to implement pharmacoepidemiological research immediately to clarify the causal relationship between Champix and psychoneurotic disorders, focusing on chronological sequence and dosage.
On August 7th 2009, after the submission of our written request, the MHLW requested that Pfizer Japan revise Paxil’s package insert.
As a result, the warning section on the package insert was revised.
The revised “Warnings” state that the adverse events mentioned above have been reported.
But the opening sentence adds that “quitting smoking is reported to be associated with various symptoms regardless of treatment, and sometimes worsens underlying psychiatric diseases”.
On the other hand, it does not specify that some of these symptoms have occurred in patients taking Champix who continued to smoke.
There is also no advice in the “Warnings”section that the patient should stop taking Champix and contact a health care provider immediately if neuropsychiatric symptoms are observed.
The revised “Warnings”on the package insert for Champix are still insufficient.
Thus, on December 28th 2009, we submitted written requests once again to the MHLW and Pfizer Japan urging more adequate revisions of the package insert.
