Key Facts

Smoking is the single greatest cause of preventable illness and premature death in the UK. It is a major risk factor for lung cancer, COPD, cardiovascular disease, stroke, and many other conditions. Effective smoking cessation interventions exist and are highly cost-effective.

Epidemiology

Approximately 12.9% of UK adults (6.4 million people) smoke (2022 data). Prevalence is higher in lower socioeconomic groups (25% in routine/manual occupations vs 8% in managerial/professional). Smoking causes approximately 78,000 deaths per year in the UK and is responsible for ~16% of all adult deaths. About 70% of smokers want to quit; approximately 50% make a quit attempt each year but only 3-5% succeed without support.

Aetiology

Nicotine addiction involves:

• Physical dependence: nicotine binds to α4β2 nicotinic acetylcholine receptors in the ventral tegmental area → dopamine release in nucleus accumbens (reward pathway)
• Psychological dependence: behavioural associations (morning cigarette, stress relief, social situations)
• Social factors: peer group, family, socioeconomic deprivation

Pathophysiology

Cigarette smoke contains >7,000 chemicals including >70 known carcinogens. Key harmful effects:

• Nicotine: addiction, sympathomimetic effects (raised HR/BP)
• Carbon monoxide: binds haemoglobin (reduced O₂ carrying capacity), endothelial damage
• Tar: contains carcinogens (polycyclic aromatic hydrocarbons, nitrosamines)
• Oxidants: cause airway inflammation, mucus hypersecretion, protease-antiprotease imbalance (COPD), endothelial dysfunction (atherosclerosis)
• Within 20 minutes of quitting: HR and BP start to normalise; within 1 year: CVD risk halved; within 10-15 years: lung cancer risk approaches non-smoker level

Assessment

• Smoking status: current, ex, never — record in all consultations
• Quantification: cigarettes per day, pack-years (packs/day × years smoked)
• Dependence assessment: Fagerström Test for Nicotine Dependence — time to first cigarette is the strongest predictor (within 5 minutes = high dependence)
• Motivation to quit: assess readiness to change (pre-contemplation → contemplation → preparation → action → maintenance)

Nicotine Withdrawal Symptoms

• Onset within hours, peak at 2-3 days, most resolve within 2-4 weeks
• Irritability, anxiety, difficulty concentrating
• Increased appetite, weight gain (average 4-5 kg)
• Cravings (may persist for months)
• Insomnia, depressed mood

Red Flags

• New respiratory symptoms in smoker (haemoptysis, persistent cough, weight loss) — urgent cancer investigation
• Pregnancy (smoking causes FGR, preterm birth, placental abruption) — urgent cessation support
• Pre-operative patients — 4-8 weeks cessation reduces surgical complications

Bedside

• Exhaled carbon monoxide (CO) monitoring: confirms smoking status and measures exposure; >10 ppm suggests active smoking; useful for motivation and monitoring
• Fagerström Test for Nicotine Dependence (FTND): 6-item questionnaire; scores 0-10
• Motivation assessment: readiness ruler (1-10 scale)

Bloods

• Cotinine level (saliva, urine, or blood): metabolite of nicotine; confirms smoking status (>10 ng/mL suggests active smoking)
• Not routinely measured in clinical practice but used in research and insurance

Imaging

• CXR: if respiratory symptoms or suspicion of smoking-related disease
• Low-dose CT thorax: for lung cancer screening in high-risk populations (NHS Targeted Lung Health Check programme for ages 55-74 with smoking history)

Special Tests

• Spirometry: baseline lung function in smokers — early detection of COPD
• Cardiovascular risk assessment (QRISK3): smoking status is a key input

Non-pharmacological

• Very Brief Advice (VBA): ASK (smoking status), ADVISE (best way to quit is with support + medication), ACT (refer to stop smoking service or prescribe) — <30 seconds, doubles quit attempts
• Behavioural support: individual counselling, group therapy, or telephone support (NHS Smokefree helpline: 0300 123 1044); increases quit rates 2-3 fold
• Digital support: NHS Smokefree app, online resources
• Motivational interviewing: for ambivalent smokers

Pharmacological

• Varenicline (first-line per NICE NG209): partial agonist at α4β2 nicotinic receptor — reduces cravings and withdrawal while blocking rewarding effects of smoking
  • Dose: 0.5 mg OD days 1-3, 0.5 mg BD days 4-7, then 1 mg BD for 11 weeks (set quit date for day 8-14)
  • EAGLES trial: no increased neuropsychiatric risk vs NRT or placebo
  • Quit rates: ~25% at 1 year (vs ~15% NRT, ~10% placebo)
• NRT (nicotine replacement therapy): available OTC; combination therapy most effective:
  • Patch (21 mg/24h, 15 mg/16h) for background nicotine PLUS short-acting (gum 2-4 mg, inhalator, spray, lozenge) for breakthrough cravings
  • Safe in cardiovascular disease, pregnancy (NRT preferred over smoking)
• Bupropion (Zyban): noradrenaline and dopamine reuptake inhibitor; 150 mg OD days 1-6, then 150 mg BD for 7-9 weeks
  • Contraindicated in epilepsy, eating disorders, bipolar disorder
  • Lowers seizure threshold (~1 in 1,000)
• E-cigarettes/vapes: less harmful than smoking (~95% per PHE); can be recommended as cessation aid; regulated as consumer products in UK
• Cytisine: emerging evidence as cheaper alternative to varenicline (available in some countries)

Surgical/Interventional

• Not applicable

Referral Criteria

• All smokers to local stop smoking service (or GP-based cessation support)
• Pregnant smokers: urgent referral to specialist cessation service
• In-patients: offer NRT/counselling during admission; follow-up post-discharge
• Pre-operative: 4-8 weeks smoking cessation before elective surgery

Unaided quit attempts succeed in only 3-5% at 1 year. Behavioural support alone increases this to 5-10%. NRT doubles quit rates (~15% at 1 year). Varenicline + behavioural support achieves ~25% 1-year abstinence. The health benefits of quitting are substantial at any age: quitting at 30 gains ~10 years of life expectancy; quitting at 60 gains ~3 years. Relapse is common — most successful quitters have made multiple previous attempts.

Timeline of Health Benefits After Quitting

Comparison of Pharmacological Aids