cidofovir, brand name vistide, is an injectable antiviral medication primarily used as a treatment for cytomegalovirus (cmv) retinitis (an infection of the retina of the eye) in people with aids. cidofovir was approved for medical use in 1996. medical use dna virus its only indication that has received regulatory approval worldwide is cytomegalovirus retinitis. cidofovir has also shown efficacy in the treatment of aciclovir-resistant hsv infections. cidofovir has also been investigated as a treatment for progressive multifocal leukoencephalopathy with successful case reports of its use. despite this, the drug failed to demonstrate any efficacy in controlled studies. cidofovir might have anti-smallpox efficacy and might be used on a limited basis in the event of a bioterror incident involving smallpox cases. brincidofovir, a cidofovir derivative with much higher activity against smallpox that can be taken orally has been developed. it has inhibitory effects on varicella-zoster virus replication in vitro although no clinical trials have been done to date, likely due to the abundance of safer alternatives such as aciclovir. cidofovir shows anti-bk virus activity in a subgroup of transplant recipients. cidofovir is being investigated as a complementary intralesional therapy against papillomatosis caused by hpv. it first received fda approval on 26 june 1996, tga approval on 30 april 1998 and ema approval on 23 april 1997. it has been used topically to treat warts.