Lucan · Conditions

Smoking cessation

Australian guidance: RACGP Supporting Smoking Cessation — Guide for Health Professionals

1. Definition and epidemiology

Smoking cessation refers to the process of discontinuing tobacco smoking, which remains the single most important preventable cause of premature death and morbidity in Australia. Daily smoking prevalence in Australia fell from approximately 24% in 1991 to 12.2% by 2016, giving Australia one of the lowest smoking rates among OECD nations, though Aboriginal and Torres Strait Islander populations continue to smoke at disproportionately high rates. Despite the overall decline, smoking remains the leading behavioural risk factor for preventable disease and premature death across all Australian states and territories.

2. Pathophysiology

Nicotine is the primary addictive constituent of tobacco. After inhalation, nicotine binds to nicotinic acetylcholine receptors (nAChRs) in the mesolimbic reward pathway, triggering dopamine release in the nucleus accumbens and producing reinforcing pleasurable effects. Repeated exposure leads to upregulation of nAChRs and neuroadaptation, such that cessation of nicotine supply produces a withdrawal syndrome driven by receptor hypersensitivity and relative dopamine deficiency. Symptoms include irritability, anxiety, depressed mood, difficulty concentrating, increased appetite, and intense craving. It is the non-nicotine components of combusted tobacco, including polycyclic aromatic hydrocarbons, carbon monoxide, and oxidant gases, that drive cancer initiation, accelerate atherosclerosis, and cause chronic obstructive pulmonary disease rather than nicotine itself. Nicotine in therapeutic formulations is therefore substantially safer than continued smoking, though it carries residual risk in vulnerable developmental stages including pregnancy and adolescence.

3. Clinical presentation and diagnostic criteria

Nicotine dependence is a clinical diagnosis inferred from the history. Key indicators include smoking within 30 minutes of waking, smoking more than 10 cigarettes per day, and reporting significant craving or withdrawal symptoms on previous quit attempts. The Fagerstrom Test for Nicotine Dependence (FTND) is a validated six-item questionnaire that quantifies dependence severity and can guide pharmacotherapy dosing decisions. On examination, findings may include tar staining of the fingers and teeth, chronic cough, wheeze, and signs of cardiovascular disease. There is no formal DSM or ICD threshold that must be met before offering pharmacotherapy; the RACGP guideline recommends offering brief cessation advice to all people who smoke regardless of assessed dependence severity.

4. Investigations and AU-specific cutoffs

Investigations are directed at identifying smoking-related organ damage rather than diagnosing the smoking behaviour itself. Spirometry with a post-bronchodilator FEV1/FVC ratio below 0.70 confirms airflow obstruction consistent with COPD in symptomatic smokers. Fasting lipid profile, fasting glucose or HbA1c, and blood pressure measurement form part of absolute cardiovascular risk assessment using the Australian cardiovascular risk calculator, which is recommended for all adults aged 45 years and over (or 35 years and over for Aboriginal and Torres Strait Islander people). Chest X-ray is not routinely indicated for cessation assessment but should be considered in the presence of haemoptysis or constitutional symptoms. Biochemical confirmation of abstinence using exhaled carbon monoxide concentration below 8 parts per million (ppm) is used in clinical trials and may be applied in high-intensity cessation programs to verify self-reported quit status.

5. Management

The RACGP guideline establishes a clear framework for brief intervention in every clinical encounter. All people who smoke should receive brief advice to quit (Recommendation 1, strong recommendation, high certainty). Practices and healthcare services should maintain a system for identifying and documenting tobacco use status (Recommendation 2). Follow-up should be offered to all people attempting to quit (Recommendation 4).

For people with evidence of nicotine dependence, pharmacotherapy should be recommended in the absence of contraindications, always in combination with behavioural support (Recommendation 5, strong recommendation, high certainty). Behavioural support encompasses individual or group counselling, cognitive and behavioural coping strategies, written information, and telephone quit-line referral. Quitline (13 7848) provides free telephone call-back counselling and is available nationally; referral should be offered to all people who smoke (Recommendation 16, strong recommendation, high certainty).

For those in whom a structured quit date is set, the treating clinician should offer follow-up contact at two weeks and again at one to three months to review progress, reinforce adherence, and manage side effects.

6. Pharmacology and AU PBS notes

Three first-line pharmacotherapy options are licensed and available in Australia: nicotine replacement therapy (NRT), varenicline, and bupropion sustained release.

Varenicline (Champix) is a partial agonist at the alpha-4 beta-2 (a4b2) nAChR. It alleviates withdrawal and craving while simultaneously blocking the reward response if cigarettes are smoked. Varenicline is the most effective single pharmacotherapy, increasing six to twelve month sustained abstinence rates by 15% compared with placebo and approximately 7% compared with bupropion. Standard dosing is 0.5 mg daily for days one to three, 0.5 mg twice daily for days four to seven, then 1 mg twice daily for twelve weeks; a further twelve weeks may be considered to reduce relapse (Recommendation 11). For creatinine clearance below 30 mL/min, reduce daily dose to 1 mg. Nausea occurs in approximately 30% of patients but rarely leads to discontinuation; it is minimised by taking tablets with food. Sleep disturbance and abnormal dreams are also reported. Varenicline is contraindicated in pregnancy. It is PBS subsidised.

Nicotine replacement therapy is available without prescription in multiple formulations: transdermal patch (21 mg/24-hour, 14 mg/24-hour), gum (2 mg, 4 mg), lozenge (1.5 mg, 2 mg, 4 mg), inhalator (15 mg), and mouth spray (1 mg/spray). Combination NRT (patch plus an oral acute form) is more effective than monotherapy and is recommended for those with evidence of nicotine dependence (Recommendation 6, strong recommendation, moderate certainty). For those who smoke within 30 minutes of waking or smoke more than ten cigarettes per day, initial dosing is typically a 21 mg/24-hour patch plus a 4 mg gum, lozenge, or equivalent oral form. NRT is safe in stable cardiovascular disease; caution is advised for patients with recent myocardial infarction, unstable angina, severe arrhythmias, or recent cerebrovascular events (Recommendation 8). Selected NRT formulations (patch, gum, lozenge) are PBS subsidised under an eligibility-based scheme, with prescriptions limited to patients meeting defined nicotine dependence criteria.

Bupropion sustained release (Zyban) is a non-nicotine oral therapy originally developed as an antidepressant. It reduces withdrawal urge and increases long-term cessation rates by approximately 60% compared with placebo. It is less effective than varenicline and equivalent in efficacy to NRT monotherapy. Standard dosing is 150 mg daily for days one to six, then 150 mg twice daily for seven to twelve weeks. Bupropion is contraindicated in people with a history of seizures, current or recent (within 14 days) monoamine oxidase inhibitor use, eating disorders, or pregnancy. Seizure risk is 0.1%; concomitant medications that lower seizure threshold require caution. It is PBS subsidised.

Nortriptyline is a second-line agent due to its adverse effects profile and should only be considered when first-line options are contraindicated or have failed (Recommendation 14, strong recommendation, moderate certainty). It is not TGA-approved for smoking cessation and does not carry a PBS indication for this use.

Nicotine vaping products (NVPs) may be considered in people who have failed first-line TGA-approved pharmacotherapy combined with behavioural support, are still motivated to quit, and provide informed consent regarding the unknown long-term health effects and unestablished safety profile of NVPs in Australia (Recommendation 15, conditional recommendation, low certainty). As of 1 January 2024, nicotine e-liquids require a prescription for legal supply in Australia under TGO 110. Prescribers should avoid concentrations above 20 mg/mL free-base nicotine, limit supply to a maximum of three months per prescription, and ensure follow-up and behavioural support are in place.

7. Complications and monitoring

Smoking causes or substantially worsens lung cancer, oesophageal, bladder, renal, cervical, and head and neck cancers; ischaemic heart disease; peripheral vascular disease; stroke; COPD; and type 2 diabetes. Cessation at any age confers meaningful health benefits, with cardiovascular risk falling substantially within one to two years of quitting.

During pharmacotherapy, monitor for neuropsychiatric symptoms at every review visit, particularly in patients with pre-existing mental illness. Patients should be explicitly advised to report anxiety, depression, behavioural changes, or suicidal ideation and to return promptly if these develop. Although the EAGLES trial found no significant increase in neuropsychiatric adverse events with varenicline or bupropion compared with placebo or NRT, the underlying quit process itself carries increased psychological stress, and monitoring remains mandatory. When bupropion is used with NRT, blood pressure should be checked at follow-up. Approximately 50% of those who have quit at the end of a standard pharmacotherapy course will relapse, underscoring the importance of scheduled follow-up and consideration of extended or repeated treatment courses where clinical criteria are met.

Longer term surveillance for patients who quit includes annual spirometry in those with pre-existing airflow limitation, ongoing absolute cardiovascular risk review, and opportunistic cancer screening in line with standard Australian preventive care guidelines.

Written for Australian practice and grounded in the guidance named above. Study material only — not medical advice. Always check against current guidelines.