TABLE 1.

. Effect of combinations of rimantadine with NA inhibitors on extracellular yield of A/New Caledonia/20/99 (H1N1) influenza virus in MDCK cells

Concn of rimantadine (μM)	Virus yield (log10 TCID50/0.2 ml) for combination drug indicated:a
	None	Zanamivir at:b			Oseltamivir carboxylate at:b			Peramivir at:b
		0.001 μM	0.01 μM	0.1 μM	0.001 μM	0.01 μM	0.1 μM	0.001 μM	0.01 μM
0	7.5 ± 0.4	6.7 ± 0.4c	5.1 ± 1.0d	1.9 ± 0.4d	7.5 ± 0	4.8 ± 1.0d	0.5 ± 1.0d	3.1 ± 0.7d	0.4 ± 0.5d
5	6.6 ± 0.3d	6.1 ± 0.4e,g	3.7 ± 0.5f,g	1.0 ± 0.7f,g	7.0 ± 0f,h	4.6 ± 1.0e	<0.1f	2.3 ± 0.4f,g	<0.1f
20	4.4 ± 0.8d	4.0 ± 0.4e,h	1.4 ± 0.5f,h	<0.1f,h	5.8 ± 0.4h	4.1 ± 0.4	<0.1f	1.5 ± 0.4f,g	<0.1f
40	3.7 ± 0.5d	3.0 ± 0.6e,h	1.0 ± 0.7f,h	<0.1f,h	4.2 ± 0.4h	2.8 ± 0.3f,g	<0.1f	0.8 ± 0.3f,h	<0.1f
80	2.3 ± 1.1d	<0.1f,h	<0.1f,h	<0.1f,h	1.8 ± 0.3h	0.6 ± 1.3e,h	<0.1f	0.3 ± 0.3f,h	<0.1f

^aDrugs were added 30 min before inoculation with virus. Virus in the culture supernatant was titrated in MDCK cells. Each value is the mean ± standard error (SE) for at least three determinations. The limit of virus detection was 0.1 log₁₀ TCID₅₀ per 0.2 ml.

^bP was <0.0001 with the F test for the synergy in the experimental range.

^cP was <0.05 compared with saline-treated controls.

^dP was <0.01 compared with saline-treated controls.

^eP was <0.05 compared with rimantadine used alone.

^fP was <0.01 compared with rimantadine used alone.

^gP was <0.05 compared with zanamivir, oseltamivir carboxylate, or peramivir used alone.

^hP was <0.01 compared with zanamivir, oseltamivir carboxylate, or peramivir used alone.