Text adapted in 2021 from Smoking Cessation in The Primary Care Addiction Toolkit (online only). A complete list of Toolkit authors, editors and contributors is available here.
Varenicline
How varenicline works
Varenicline is a partial nicotine agonist that is selective for the alpha4beta2 nicotinic acetylcholine receptor. It blocks the binding of exogenous nicotine to the receptor, with a subsequent reduction in the stimulation of the mesolimbic dopamine system in response to inhaling nicotine. Varenicline also provides a low level of stimulation in the absence of inhaled nicotine
In short, varenicline provides a mild nicotine replacement effect while inhibiting the pleasurable effects of smoking.
Candidates for varenicline
Varenicline is an approved smoking cessation medication, similar to NRT and bupropion, and is considered a first line medication.
It is the most effective medication for smoking cessation and outperforms both NRT and bupropion. It has been found to be safe for use among populations with stable psychiatric conditions (Anthenelli et al, 2016).
Advising patients how to take varenicline
Tell patients the following:
- Take varenicline after meals with a glass of water.
- Make a quit attempt no longer than 4 weeks into the medication course.
- Do not use NRT products with varenicline because they increase the risk of nausea.
- Stay on varenicline for at least 12 weeks.
- If you succeed in quitting smoking, strongly consider using varenicline for another 12 weeks.
- The most common side-effects are nausea, constipation, flatulence and increased dreams.
- Side-effects tend to settle after two to three weeks.
- If the side-effects are intolerable, try a lower dose before discontinuing the medication.
Practice recommendations for health care providers
The U.S. Food and Drug Administration ([FDA], 2015) recently updated the labeling for varenicline to include the following recommendations for health care providers:
- Advise patients to reduce the amount of alcohol they consume while taking varenicline until they know whether the drug affects their tolerance for alcohol.
- Weigh the potential risk of seizures against the potential benefits before prescribing varenicline in patients with a history of seizures or other factors that can lower the seizure threshold.
- Advise patients to discontinue varenicline and seek medical attention immediately if they experience a seizure while on treatment.
- Advise patients to immediately stop taking varenicline if they develop agitation, hostility, aggressive behaviour, depressed mood, or changes in behavior or thinking that are not typical for them, or if they develop suicidal ideation or behaviour.
- Encourage patients to read the medication guide they receive with their varenicline prescription.
- Report adverse events involving varenicline to the FDA MedWatch program.
Bupropion
Candidates for Bupropion
Bupropion is an approved medication for smoking cessation.
Factors that make it a good first-line choice include:
- current symptoms of depression
- history of intolerance of, or lack of success with, NRT or Varenicline
- patient preference.
- Contraindications include:
- history of seizures
- history of severe adverse reactions to bupropion
- current treatment with an MAO inhibitor.
Relative contraindications include:
- current alcohol or benzodiazepine abuse or dependence
- history of bipolar disorder
- history of an eating disorder.
Prescribing bupropion
- Discuss the risks and benefits of the medication with the patient.
- Explain the very small increased risk of having a seizure while on bupropion.
- Help the patient choose a quit date.
- Start at 150 mg each morning for three to five days.
- If tolerated, increase the dose to 150 mg twice daily after three to five days.
- Explain that doses should be at least eight hours apart, ideally 150 mg before breakfast and 150 mg before dinner
- Advise this medication can cause anxiety and sleep disturbances in the beginning of the treatment.
Typical quit plan using bupropion
- Start bupropion tomorrow morning.
- Set quit date in 10 days.
- Follow up with a health care provider in two weeks.
Combining bupropion with other smoking cessation medication
Although it is possible to combing bupropion with NRT, there is limited evidence that this increases chances of quitting.