TABLE 1.

Toxic threshold and efficacy of nucleoside analogues tested for properties against BDV

Compound	Toxic thresholda (μM) for:		Antiviral activity (fold)b
	OL	C6
3-Deazaguanine	20	200
ICN 10169	2	2
ICN 10776	20	2
ICN 15100	200	200
2′,3′-Dideoxyinosine (ddI)	200	200
Ribavirin	200	200	>10
ICN 17261c	20	200
FTCd	200	200
Pyrazofurin	2	2
ICN 17377c	200	20	5–10

^aMaximum concentration at which replication of treated cells was within 10% of that of the vehicle-treated cells after 1 week. 

^bReduction of virus load determined after 1 week of treatment and compared to vehicle-treated control at the highest nontoxic concentration. 

^cRibavirin analogue. 

^dβ-l-2′,3′-Dideoxy-5-fluoro-3′-thiacytidine.