Table 3.

Pharmacokinetics of analgesics used in mice

Analgesic	Dose (mg/kg)	Route	Tmax	Cmax (ng/mL)	Duration of action	Reference
Buprenorphine	5 μg/mL	PO-M	1 h	7.8	< 6 h	94
	15 μg/mL	PO-M	1 h	3.0	12 h	94
	0.03	SC	1 h	0.5	N/A	37
	0.05	SC	1 h	0.5	N/A	37
	0.1	SC	8 h	8.6	12 h	19
	0.1	SC	3 h	1.3	N/A	37
	0.1	SC	1 h	1.5	< 6 h	94
	0.1	SC	2 h	1.5	4 h	103
	0.6	SC	2 h	19.1	4 h	112
	2.0	SC	1 h	20.2	12 h	37
Buprenorphine SR	0.1zp	SC	4 h	14.5	24 h	112
	0.3zp	SC	6 h	0.8	N/A	37
	1.2zp	SC	0.5 h	5.0	12 h	37
	2.2ih	SC	2 h	11	24 h	103
	3.25ag	SC	6 h	16.3	72 h	202
	4.0ih	SC	24 h	ND	72-96 h	80
Carprofen	10	PO-G	2 h	20,300	N/A	96
	10	PO-W	12 h	17,000	N/A	96
	30	PO-W	24 h	32,000	N/A	164
	5	SC	2 h	525,000	12 h	112
Meloxicam	10	IV	5 min	365,000	4-6h	21
	10	PO	0.7 h	18,000	4-6h	21
	20	PO-G	4 h	16,700	24 h	96
	1	SC	2 h	4700	4 h	112
Meloxicam SR	6zp	SC	2 h	7300	12-24 h	112
Tramadol	25	IP	0.08 h	3010	4h	56
	25	IV	0.25 h	3710	2h	56
	25	PO-G	1 h	347	2 h	56
	25	PO	1 h	347	constant in water	56
	25	SC	0.25 h	1870	6 h	56
EMLA	18 mg/25g	Top	0.5 h	165	100 min Toxic at 21.2 mg/kg	6
	18 mg/25g	Top (open wound)	0.5 h	909	100 min	6
Bupivacaine	150 µL 0.5%	SC	1	1,000,000	approximately 4 h Toxic at >0.5%	73

Duration of action = time at which plasma level falls below therapeutic level (see Table 2)

N/A = plasma level did not exceed therapeutic level; ND = not determined

T_max = time to reach maximum concentration; C_max = maximum concentration

PO-W = oral in water; PO-M = oral in MediGel; PO-G = oral by gavage; Top = topical; SR= sustained release;

zP = manufactured by Zoopharm, Windsor, CO; ih= inhouse formulation; ag= manufactured by Animalgesics Laboratories, Millersville, MD