Table 4.

Observational assessment after intraperitoneal administration of fentanyl analogs in mice.

			PNS
Comp.	Dose	CNS	After manipulations	Reflexes	ANS
Control	–	0	0	0	0
5	Low	+	+	0	0
	Medium	++	+	+	+
	High	+++	+++	++	+
6	Low	+	+	0	0
	Medium	++	++	0	0
	High	+++	+++	++	+
7	Low	+	+	0	+
	Medium	++	++	+	+
	High	++	+++	+	++
8	Low	++	+	0	+
	Medium	++	+++	++	+
	High	+++	+++	++	+

Mice were intraperitoneally administered 0.25 (Low), 0.50 (Medium), and 0.75 (High) LD₅₀ of fentanyl analogs, viz., 5-8. The control animals received DMSO. Immediately after treatment, the animals were closely observed for 2 h by a blind observer for its effects on CNS, PNS (effects after manipulation and effects on reflexes) and ANS activities. The scorings were given as: 0 (no observational change), + (little activity), ++ (moderate flexibility), +++ (strong response) and ++++ (exaggerated response). Each treatment included three animals.