Cytomegalovirus antiviral drugs

Foscarnet and ganciclovir are two antiviral drugs, which are investigated as candidates for iontophoretic administration for local treatment of cytomegalovirus (CMV) retinitis, which is most common in AIDS patient. These two drugs were successfully delivered into the vitreous, where high therapeutic levels were maintained for up to 24 h in the case of ganciclovir [76] and for 60 h after foscarnet delivery [78]. 

Balfour HH. Management of cytomegalovirus disease with antiviral drugs. Rev Infect Dis 1990 12 S849-S860. 

Viral retinitis may be caused by herpes simplex virus, cytomegalovirus (CMV), adenovirus, and varicella zoster virus. With the highly active antiretroviral therapy (see Chapter 50), CMV retinitis does not appear to progress when specific anti-CMV therapy is discontinued, but some patients develop an immune recovery uveitis. Treatment usually involves long-term parenteral administration of antiviral drugs. Intravitreal administration of ganciclovir has been found to be an effective... 

Chrisp P, Clissold SP. Foscarnet a review of its antiviral activity, pharmacokinetic properties, and therapeutic use in immunocompromised patients with cytomegalovirus retinitis. Drugs 1991 41 104-129. 

Antiviral drugp interfere with viral reproduction by altering DNA synthesis. These drug are used in the treatment of herpes simplex infections of the eye, treatment in immunocompromised patients with cytomegalovirus (CMV) retinitis, and for the prevention of CMV retinitis in patients undergoing transplant. 

Ealagas ME, Paya C, Ruthazer R, Badley A, Patel R, Wiesner R et al. (1998) Significance of cytomegalovirus for long-term survival after orthotopic liver transplantation a prospective derivation and validation cohort analysis. Transplantation 66 1020-1028 Field AK (1999) Human cytomegalovirus challenges, opportunities and new drug development. Antivir Chem Chemother 10 219-232... 

As mentioned above, intravitreal injection of drugs should be used in many cases to achieve therapeutic intravitreal drug levels. This is especially true for cases of viral retinitis, such as cytomegalovirus (CMV) retinitis and acute retinal necrosis (ARN) which require intravitreal injection of antivirals, or for the treatment of bacterial and fungal endophthalmitis or proliferative vitreoretinopathy [305]. It still remains a controversial issue whether liposomes can reach the retina after intravitreal injections and which vesicle physicochemical characteristics should be preferred for such formulations. 

Snoeck, R., Andrei, G., and De Clercq, E. (1996) Patterns of resistance and sensitivity to antiviral compounds of drug-resistant strains of human cytomegalovirus selected in vitro. Ear. J. Clin. Microbiol. Infect. Dis. 15, 574-579. 

Foscamet is an antiviral agent that inhibits replication of all known herpes viruses, including cytomegalovirus (CMV), herpes simplex virus types 1 and 2 (HSV-1, HSV-2), human herpes virus 6 (HHV-6), Epstein-Barr virus (EBV) and varicella-zoster virus (VZV). It is indicated in the treatment of CMV retinitis in patients with AIDS treatment of acyclovir-resistant mucocutaneous HSV infections in immunocompromised patients and as combination therapy with ganciclovir for patients who have relapsed after monotherapy with either drug. 

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