The Pfizer smoking cessation drug will go on sale Down Under next month, but with warnings of links to suicidal thoughts, according to news.com.au. Packs of tablets will contain extra info warning that some patients have suffered from depression, agitation and suicidal thoughts while taking the drug. And Dear Doctor letters are being sent.

The FDA, however, has yet to take the same step (as Furious Seasons notes). Last month, the agency began a review after receiving reports from Pfizer of suicidal thoughts and aggressive and erratic behavior in patients who have taken Chantix. More than 5,000 adverse events have been reported to the FDA.

In explaining its decision, the Therapeutic Goods Administration said it reviewed reports submitted to the FDA and ordered Pfizer to issue “Dear Doctor” letters. “(Pfizer) has also amended the Champix product information to include the same post-marketing information as in the US prescribing information,” a TGA spokeswoman tells the site.

The new warning states that “there have been reports of depressed mood, agitation, changes in behaviour, suicidal ideation and suicide in patients attempting to quit smoking while taking Champix…Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.” Chantix is marketed as Champix in Australia.

Both Australia’s TGA and Pfizer have said they don’t know whether the drug itself, nicotine deprivation or some other factor could trigger the psychiatric reactions. “The TGA will continue to monitor the situation,” the spokeswoman said.

For those who don’t recall, a Texas musician named Carter Albrecht was in a drunken rage and banged on the door of a homeowner, who feared an intruder, and shot and killed the young man. Although Albrecht was later found to have tested for a high level of alcohol, he’d also begun taking Pfizer’s Chantix, the smoking-cessation drug, a week earlier and complained of vivid dreams. The case generated substantial publicity

Previously, a Pfizer spokesman wrote us that Chanitx labeling has been updated to reflect the various reports, but emphasized that “there is no scientific evidence establishing a causal relationship between Chantix and these reported events…In clinical trials involving more than 5,000 patients, adverse events related to changes in behavior or psychiatric symptoms, including suicidal ideation, were rare and occurred at a rate comparable to placebo-treated patients. There were no suicides in patients taking Chantix in our clinical trials.”

A Phase III trial did yield one suicide in a patient with a history of depression, but it was ‘not considered related’ to Chantix. Also, the US label notes that side effects reported by patients include suicidal ideation, but not suicide. By contrast, the Canadian label doesn’t say reported by patients, but does mention suicide.

Hat tip to Furious Seasons