Thursday 16 June 2011

Yet another problem with Champix (cardiovascular)

Reports today indicate slightly raised risks of cardiovascular problems. A recent trial of patients with cardiovascular disease showed patients taking Champix were slightly more likely to experience heart problems than those taking a placebo.

Written warnings accompanying the drug will warn patients of this risk and Pfizer will be required by the FDA to carry out further studies in order to establish the risk more clearly.

The risk is said to be 'small' – that will surprise no one! What beats me is why anyone will take it for such a limited outcome:
An independent randomized trial of 700 smokers with cardiovascular disease who were treated with Chantix or a placebo showed that Chantix was effective in helping patients quit smoking for as long as one year. [emphasis added]
Other problems are by now well documented:
Chantix has been associated with agitation, depression and suicidal thoughts, and, in clinical trials, linked with nightmares. Psychiatric symptoms have occurred in people without a history of mental illness and have worsened in people who already had mental illness. [emphasis added]
 To this, we can add an apparent cover up of adverse incidents involving Champix.
Federal Food and Drug Administration officials acknowledged that they asked Pfizer to resubmit thousands of records after realizing that the company was sending required reports in an inappropriate format that could not be added to the agency’s Adverse Events Reporting System, or AERS.
The French Health Minister has recently delisted Champix as a publicly funded drug. I put the point to the local NHS trust in Scotland, putting the point that the French Minister had banned the drug and requesting its withdrawal by NHS Lothian. Their reply follows:
The Scottish Government does not advise upon the licensing and safety of medicines since this is not a devolved power for the Scottish Government. As such, they are would not be in a position to withdraw this medicine from use across Scotland . The Medicines and Healthcare products Regulatory Agency (MHRA) is the UK organisation responsible for the licensing of medicines and monitoring of the safety of these medicines. Information on this organisation and its activities to ensure public safety with medicines can be found at http://www.mhra.gov.uk/index.htm 
The MHRA has had varenicline under intensive surveillance for the last couple of years to ensure that the benefit to patients continues to outweigh any potential risks. They work in collaboration with the international drug safety monitoring network to ensure safety of medicines. A copy of an article writtten for their publication the Drug Safety Update on this can be seen at http://www.mhra.gov.uk/Safetyinformatio ... /CON087722 . They encourage all healthcare professionals and patients to be vigilant in reporting any suspected side effects with this medicine. Patients and healthcare professionals can report any suspected reactions for medicines at http://yellowcard.mhra.gov.uk/
At present there has not been any indication given by the MHRA that varenicline should not be used; but continued monitoring of safety is ongoing. Therefore it remains licensed for use within the UK . Prescribers have been made aware of the risk; and should be taking this into consideration when deciding if the potential benefit to the patient before prescribing for a patient. There is no move currently to discontinue use of the medicine in appropriate patients that are likely to recive benefit. If, however, there is additional warnings issued from the MHRA of safety concerns (or indeed recommend withdrawal from use), then NHS Lothian and all other Health Boards across Scotland would then comply.
I hope this information is of use to you.
Yours sincerely
Melinda Cuthbert
Lead Pharmacist Lothian Medicines Information Service/Yellow Card Centre Scotland, Pharmacy Department, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA
Clearly MHRA needs to be notified of public concern. It is extraordinary that a drug with such effects is recommended, subsidised, to the general public, especially people with a psychiatric history, when even those without such a history are disturbed by it.  ASH Scotland's most recent update (scroll down this link) on Champix and mental health says:
Clinical trials during drug development excluded patients with active psychiatric illnesses leaving the risks associated with varenicline use in this patient population unknown. A review of the evidence in Expert Opinion on Drug Safety has concluded that although the risk of potential neuropsychiatric events is evident through voluntary reporting systems and reported cases in the literature, multiple studies and case reports support the use of varenicline in the mental health population. 
As often, I take a diametrically opposing view.

2 comments:

Rick S said...

Nonsense. It's perfectly safe - Robert West said so in July 2007: "Champix is very specific. It targets the specific receptor that seems to be crucial to nicotine dependence. This means that higher doses can be used – comparable doses in less specific drugs hit other receptors and create side effects. It reduces the craving, blocks the effects of nicotine and has hardly any contraindications. The experience from the US and France is that once people get wind of this drug they will beat a path to the doctor’s door."

http://www.ucl.ac.uk/news/news-articles/0707/07072406

Anonymous said...

Robert West should know. He's made money for oganising trials of it. See eg. from here

http://www.pulsetoday.co.uk/story.asp?storyCode=4011679&sectioncode=18

we have

Robert West is director of tobacco studies at the Cancer Research UK health behaviour unit at University College London – he has also contributed to national and international clinical practice guidelines on smoking cessation

Competing interests: Robert West undertakes research and consultancy for, and gives presentations funded by, manufacturers of smoking cessation medications, including Pfizer, GSK and Novartis.

Robert West should not be on the board of the registered charity QUIT. http://www.quit.org.uk/. There is a potential conflict of interest. Snus use is successful in cutting smoking rates, but its sale is illegal in the UK. I can't see QUIT ever campaigning to hae this law changed.