Table 2. The influence of CYP 2D6 genetic factors and breakdown of demographics.

	Poor Metabolizer(N = 11)	Intermediate Metabolizer(N = 70)	Extensive Metabolizer (N = 105)	Ultra-rapid Metabolizer (N = 6)
Total Codeine Dose (mg/kg/day)	1.4±0.6	1.1±0.4	1.2±0.5	1.2±0.3
Total No. days on codeine	2 (1–3)	2 (1–9)	2 (1–9)	2 (1–3)
Maternal Age (years)	34.5±5.5	32.9±5.7	32.6±5.51	32.0±6.8
No. times breastfed in 24hours	9 (7–10)	9 (6–13)	8.75 (3–11.5)	9 (7–13)
Baby GA (weeks)	39.3±1.4	39.0±1.2	38.5±1.3	38.8±0.4
Baby weight (grams)	3517.5±513.4	3379.4±510.8	3421.3±519.5	3199±321.8
No. reported infant ADRs (%)	0	3 (4%)	2 (2%)	0
No. reported maternal ADRs (%)	1 (9%)	7 (10%)	7 (6%)	0

Patient characteristics and reported outcomes broken down by CYP2D6 phenotype, where a poor metabolizer has a CYP2D6 activity score of 0, intermediate a score between 0.5–1.0, extensive a score between 1.5–2.0 and ultra-rapid a score of 2.5 or higher. Data are presented as mean ± standard deviation, and median (range) for nonparametric data.