Many smokers who take pills to quit the habit have developed suicidal tendency and at least 15 have committed suicide while on medication since 2008, Australian drug-control authority has said.
Hundreds of people have considered killing themselves while taking the popular quit-smoking pill Champix and 15 have in fact committed suicide, the statistics show.
In an update sent to doctors, the Therapeutic Goods Administration (TGA) said 206 "suicide-related events" and 15 suicides had been linked to the drug, which has been prescribed more than a million times since becoming available on the Pharmaceutical Benefits Scheme two and a half years ago, The Age reported.
The TGA has also received 1,025 reports of suspected adverse reactions to the drug, 67 percent of which describe psychiatric symptoms such as depression, agitation, anxiety, altered mood and aggression.
A spokeswoman for the TGA said that of the 15 suicides, 13 people were taking Champix and no other medication at the time of their death.
"Stopping smoking - with or without medication - may be associated with various psychiatric symptoms such as depressed mood [including suicidal ideation], irritability, anxiety and frustration, or anger; stopping smoking may also exacerbate any underlying psychiatric condition," the spokeswoman said.
She said a written warning added to the medication for consumers about the potential side effects was sufficient.
"All medicines have potential risks. The TGA, as a regulator, has to consider the balance between the benefits offered by any medicine and the potential risks associated with its use. These risks and benefits also need to be considered when the medicine is prescribed," she added.