TABLE 2.

Doses and duration of pharmacological treatments to quit smoking

Medication	Mechanism of action	Dosage and treatment duration	Side-effects
Nicotine replacement therapy	Acts at the level of nicotinic central nervous system receptors	16-h patches >10 cigarettes per day: 25 mg once daily×6 weeks 15 mg once daily×4 weeks 10 mg once daily×2 weeks 5 mg once daily×2 weeks <10 cigarettes per day: 10 mg once daily×6 weeks 5 mg once daily×2 weeks 24-h patches >10 cigarettes per day: 21 mg once daily×6 weeks 14 mg once daily×4 weeks 7 mg once daily×2 weeks <10 cigarettes per day: 14 mg once daily×6 weeks 7 mg once daily×2 weeks	Redness or itching of skin where patch applied, urticaria, headache, dizziness, nausea/vomiting, insomnia
		Chewing gum 2–4 mg or tablets 1–2 mg if craving	Mouth soreness, throat irritation, jaw ache, dyspepsia, flatulence, nausea, emesis, unpleasant taste, possible allergic reactions
Bupropion	Inhibits neuronal reuptake of dopamine and norepinephrine in the nucleus accumbens and locus coeruleus	≥12 weeks: 150 mg per 12 h First week progressive dose	Insomnia (most common), dry mouth, anxiety, irritability, restlessness, headache, tinnitus, skin rash, seizures (rare and most alarming)
Varenicline	Partial agonist for the α4β2 nicotinic acetylcholine receptor (dopamine release in the nucleus accumbens)	≥12 weeks: Days 1–3: 0.5 mg once daily Days 4–7: 0.5 mg twice daily Days 8+: 1 mg twice daily	Nausea (most common), insomnia, abnormal dreams, sleep disturbance, dyspepsia, abdominal pain, constipation, flatulence, emesis, dizziness, dry mouth