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Depression and suicide associated with anti-smoking drug, Champix

Numerous lawsuits have been filed against Pfizer, accusing the manufacturer of failing to accurately warn consumers about the dangers associated with the use of Champix.

Adverse Psychiatric Symptoms associated from the use of Champix include:

  • Nervousness
  • Tension
  • Anxiety
  • Depression
  • Unusual behaviour
  • Suicidal thoughts
  • Suicidal attempts

What is Champix?

Pfizer manufactures and markets a smoking cessation medication called Chantix® in the United States of America or, in South Africa and the rest of the world, Champix®, known generically as varenicline.

Champix is marketed as being designed to block the effects of nicotine in the body. There are receptors for nicotine in the brain called nicotinic acetylcholine receptors. When cigarette smoke is inhaled, nicotine attaches to these receptors and this binding activates the mesolimbic dopamine system. This triggered release of dopamine results in a feeling of pleasure and the desire to repeat this feeling reinforces the need to keep smoking.

Varenicline (as varenicline tartrate) is the medicinal ingredient of Champix. The claimed mechanism of action of Champix is the binding of varenicline to the α4β2 subtype of the nicotinic acetylcholine receptors. By binding to these receptors, varenicline induces two results.

  • Firstly, it signals the release of dopamine but not to the full extent that nicotine does because of its partial binding of the receptor. That is, varenicline is a partial agonist in that it activates release of 35% to 60% of the dopamine which nicotine would have caused to flow if occupying the exact same acetylcholine receptors.
  • Second, it acts as a physical antagonist by competitively binding to the receptor and thereby blocking nicotine or any natural ligand from so binding. If Champix is taken as directed, in theory, within 4-5 days, therapeutic levels should be achieved and inhaled nicotine arriving in the brain which would normally generate a sense of perceived pleasure would find most acetylcholine receptors already occupied and occupied consistently for the duration that Champix is taken. Therefore, Champix theoretically works because the cravings for nicotine are diminished and psychological pleasure derived from smoking is reduced but, essentially, Champix regulates and restricts dopamine and blocks pleasure sensors. Slowing down the flow of dopamine in the brain leads to negative mood modification and its consequences which, importantly for the purposes of this potential action, include anxiety, slowed thought, nervousness, hallucinations, depression and suicidal ideation.

Common side effects include:

  • Headache
  • Weakness/fatigue
  • Nausea
  • Stomach pain
  • Constipation
  • Indigestion
  • Vomiting
  • Increase in appetite
  • Unpleasant taste in mouth
  • Insomnia and vivid, abnormal dreams

Talk to a Champix specialist advisor today