TABLE 2

Effects of H₁ antagonists on the potency of cocaine

Drugs	H₁ Antagonist Dose	Cocaine ED₅₀ Value (95% CL)	Relative Potency (95% CL)
mg/kg i.p.
Cocaine alone	Vehicle	3.42 (2.72–4.36)
Cocaine with promethazine	1.0	2.82 (1.94–3.97)	1.22 (0.845–1.77)
	3.0	2.36 (1.34–3.61)	1.44 (0.922–2.33)
	5.6	3.54 (2.03–6.82)	0.985^a (0.618–1.57)
Cocaine with triprolidine	10	2.59 (1.29–4.47)	1.06 (0.609–1.87)
	24	2.65 (0.931–5.62)	1.04 (0.555–1.95)
	30	N.S.	3.61^b (1.20–9.22)
Cocaine with chlorpheniramine	1	2.37 (0.747–4.78)	1.25 (0.722–2.27)
	3	2.38^a (1.85–2.96)	1.30^a (0.916–1.87)
	17	0.243 (0.00107–0.743)	6.40^b (3.12–16.6)
Cocaine with mepyramine	17	1.31 (0.544–2.62)	1.90^b (0.984–3.71)
	24	0.287 (0.0656–0.919)	9.34 (4.95–17.4)
	30	N.S.	6.84^b (1.94–25.4)

N.S., nonsignificant linear regression precludes calculation of an ED₅₀ value.
↵ a Deviation from linearity in regression analysis dictates that the number be considered an estimate
↵ b Deviation from parallel in regression analysis dictates that the number be considered an estimate