Table 2.

Treatment groups of diabetic neuropathic pain.

Group number	Group name	Compound name	Doses (mg/kg)	Route	Volume (ml/kg)	Animal numbers
One-time acute treatment
1	Sham	N/A	N/A	N/A	N/A	10
2	20% PEG600/water	Vehicle	0	i.p.	2	10
3	Mexiletine 30 mg/kg	Mexiletine	30	p.o. gavage	2	10
4	Mexiletine 40 mg/kg	Mexiletine	40	p.o. gavage	2	10a
5	Nav1.7 blocker 30 mg/kg	CC4148	30	i.p.	2	10
6	Pregabalin 30 mg/kg	Pregabalin	30	p.o. gavage	2	10
Chronic treatment for 8 weeks
7	Sham	N/A	N/A	N/A	N/A	15b
8	Water	Vehicle	0	p.o. drinking	Ad libitum	18
9	Pregabalin 30/15/20 mg/kg	Pregabalin	30/15/20c	p.o. drinking	Ad libitum	12

^aMexiletine 40 mg/kg group of rats had been dosed with Mexiletine 30 mg/kg one week prior, during week 5 to week 6 after STZ injection. ^bTen of the sham rats were reused from the sham group in the acute study. ^cPregabalin was dosed daily for 8 weeks from week 12 to week 20. Pregabalin was given at 30 mg/kg/day on day 1 and reduced to 15 mg/kg/day from day 2 onwards due to adverse side effects. After 6 weeks of treatment, the dose was increased to 20 mg/kg/day for the last two weeks of the study due to tachyphylaxis (efficacy declined with time).