Smoking Cessation

Nicotine replacement therapy (NRT)

Roughly doubles the chance of successfully quitting. Can be used in pregnancy if unassisted quit attempts have failed.

• Dose: >10 cigarettes/day — patch 21 mg/24h or 25 mg/16h; <10/day or <45 kg — patch 14 mg/24h or 10 mg/16h.
• Duration: 12 weeks.
• Combination therapy (a long-acting patch plus a short-acting form — gum, oral spray, inhaler, or lozenge) is more effective for quitting than single-form NRT. It is not PBS-subsidised as a combination, however — PBS-subsidised NRT covers either a patch or an oral form (gum/lozenge) alone, not both together. A patient who does not succeed using PBS-subsidised patches alone can still access other PBS-subsidised smoking cessation therapies (varenicline or bupropion) within the same 12-month period.

Varenicline (Champix)

Has the best evidence of the three pharmacotherapies. Not recommended in pregnancy or breastfeeding, or in adolescents. Side effects: nausea, vivid dreams, rarely seizures or SJS; may worsen intercurrent psychiatric illness (neuropsychiatric effects have been reported, though a causal link to varenicline itself remains unclear).

• Course: 12 weeks; a second, PBS-subsidised 12-week course can be used after a successful quit to prevent relapse.
• Dose (titration): 0.5 mg daily for 3 days → 0.5 mg twice daily for 4 days → 1 mg twice daily. Reduce the dose for intolerable nausea or other adverse effects.
• Can be combined with NRT, which enhances effectiveness — trial evidence is specifically for combination with a nicotine patch. There is no clinical trial evidence for combining varenicline with an oral, short-acting NRT form, though this combination is used in practice.

Bupropion (Zyban)

Contraindicated in seizure disorder, eating disorders, and with current or recent MAOI use within 14 days. Not recommended in pregnancy or breastfeeding; no evidence of increased cardiovascular risk during treatment. Dose: 150 mg once daily for 3 days, then 150 mg twice daily for 9 weeks. Start while the patient is still smoking, then quit 1–2 weeks later (earlier quitting is fine if the patient is ready).