Table 5. Summary of all-cause treatment-emergent adverse events occurring in ⩾5% of either treatment group.

Parameter	Varenicline 1 mg twice daily(n = 376)	Nicotine titrated from 21 mg patches(n = 370)
Any adverse event	319 (84.8)	260 (70.3)
Treatment discontinuations due to adverse events	30 (8.0)	16 (4.3)
Dose reductions or temporary withdrawal from study medication	44 (11.7)	25 (6.8)
Deaths	0 (0.0)	0 (0.0)
Serious adverse events	2 (0.5)	8 (2.2)
Most frequent adverse events
Nausea	140 (37.2)	36 (9.7)
Insomnia	80 (21.3)	71 (19.2)
Headache	72 (19.1)	36 (9.7)
Abnormal dreams	44 (11.7)	31 (8.4)
Constipation	31 (8.2)	9 (2.4)
Dizziness	28 (7.4)	13 (3.5)
Disturbance in attention	24 (6.4)	5 (1.4)
Vomiting	23 (6.1)	4 (1.1)
Diarrhoea	22 (5.9)	10 (2.7)
Flatulence	22 (5.9)	5 (1.4)
Dysgeusia	22 (5.9)	4 (1.1)
Abdominal pain (upper)	21 (5.6)	4 (1.1)
Fatigue	21 (5.6)	9 (2.4)

Data presented as n (%).