Varenicline (Chantix) and Possible Adverse Events

Written By:
Paulette Campbell RN-BC, BSN, MJ
Certified Legal Nurse Consultant

Varenicline (known as Chantix on the market) is a smoking cessation aid that acts on sites in the brain affected by nicotine. It is believed to help those who wish to stop smoking by providing some nicotine effects to ease the withdrawal symptoms and by blocking the effects of nicotine from cigarettes if users resume smoking. Varenicline was first approved in May of 2006 and is manufactured by Pfizer, Inc.

In the fourth quarter of 2007, reports to the FDA concerning Varenicline use accounted for 988 serious injuries. At that time, the FDA published a public health advisory about psychiatric symptoms (November 2007). In their statement the FDA warned about; “changes in behavior, agitation, suicidal ideation, and attempted and completed suicides”.

The Institute for Safe Medication Practice has reported that there have been additional potential adverse events. It is important to point out that adverse events by themselves does not mean casual link. Those adverse events include:

• Accident & Injuries (total of 173 serious events, 28 road traffic accidents and 77 falls)
• Vision Disturbance (approximately 148 cases)
• Heart Rhythm Disturbance (224 potential cardiac rhythm disturbances) - This category also includes loss of consciousness which could be a non-cardiac incident
• Seizures, Abnormal Muscle Spasms or Movements (80 seizures were reported, 372 incidents of various movement disorders such as tremors, muscle spasms, twitching, etc)
• Moderate and severe skin reactions (338 cases of hives or swelling of the tongue, face, eyes, lips or other areas, also 65 were classified as severe)
• Diabetes (544 reports suggesting a potential link between Varenicline and loss of glycemic control)

In their discussion about Varenicline, the Institute for Safe Medicine Practice voiced serious safety concerns about individuals who operate motor control equipment where laps in alertness could lead to serious injury. This concern is due to reports of sudden loss of consciousness, seizures, muscles spasms, vision disturbances, hallucinations and paranoia.

At the request of the FDA, Pfizer has changed the full prescribing information in the warnings and precautions section. It now states that there is a possibility of serious neuropsychotic symptoms. Further, the following recommendations have been made for health care providers;

• Healthcare providers should monitor all patients taking Chantix for serious neuropsychotic symptoms
• Patients with serious psychiatric illness such as mental illness, bipolar, and major depressive disorder should not be prescribed Varenicline

Patient recommendations include the following;

• Inform healthcare providers of any history of psychiatric illness
• Be alert to changes in mood and behavior
• Immediately report any changes in mood or behavior to your healthcare professiona
• Vivid or strange dreams may occur while taking this medication

Our medical legal consulting team at Medical Jurisprudence, Inc can help you with any medical cases you have including Varenicline litigation. For more information regarding our services, you can contact our offices at info@medicaljurisprudence.com or 630-551-0978.