TABLE 3.

Selected acyclic nucleoside analogue drugs listed in decreasing order of in vitro efficacy against FHV-1 ^{3,4,38–40,48}

Drug	Mode of action	In vitro efficacy against FHV-1 (ED50, μM) 38–40	Dosage	Comments
Trifluorothymidine (trifluridine, 5FT)	Thymidine analogue	0.67	1% solution topically q4-6h for 21 days	Can be irritant in some cats No controlled clinical trials reported
Ganciclovir	Guanosine analogue	5.2	0.15% gel topically q4-6h for 21 days	No controlled clinical trials reported
Idoxuridine	Thymidine analogue	4.3–6.8	0.1% ointment topically q4-6h for 21 days	No controlled clinical trials reported
Cidofovir	Cytosine analogue	11.0	0.5% solution topically q12h for 21 days	Controlled clinical trial reported clinical efficacy 42
Famciclovir/penciclovir	Guanosine analogue	13.9	90 mg/kg PO q8h for 21 days	Controlled clinical trial reported clinical efficacy 44
Vidarabine	Adenosine analogue	21.4	3% ointment topically q4-6h for 21 days	No controlled clinical trials reported
Aciclovir	Guanosine analogue	57.9–85.6	3% ointment topically q4-6h for 21 days	No controlled clinical trials reported although prospective clinical trial suggested efficacy 48