Table 3

Adverse events with oral opioid and placebo in randomised trials in chronic non-malignant pain

Oral opioid

Placebo

Number of patients

Event rate (%)

Number of patients

Event rate (%)

Adverse event

With AE

Total

Average

95% CI

With AE

Total

Average

95% CI

Patients experiencing any adverse event

1387

2743

51

49–53

122

404

30

26–34

Withdrawals

Adverse event withdrawal

933

4221

22

21–23

51

721

7.1

5.2–8.9

Lack of efficacy withdrawal

177

2719

6.5

5.6–7.4

135

679

20

17–23

Specific adverse events

Dry mouth

100

399

25

21–29

3

94

3.2

0–6.7

Nausea

902

4314

21

20–22

40

718

5.6

3.9–7.2

Constipation

606

4043

15

14–16

32

643

5.0

3.3–6.7

Dizziness

530

3899

14

13–15

28

623

4.5

2.9–6.1

Drowsiness or somnolence

425

3078

14

13–15

21

531

4.0

2.3–5.6

Pruritus

106

794

13

11–16

7

336

2.1

0.6–3.6

Vomiting

345

3330

10

9.3–11

12

497

2.4

1.1–3.8

AE, adverse event; CI, 95% confidence interval.

Moore and McQuay Arthritis Research & Therapy 2005 7:R1046   doi:10.1186/ar1782