Ganciclovir intravitreal administration

Ganciclovir Intravenous administration Intravitreal injection Intravitreal implant Oral administration (valganciclovir) Primary toxicity = neutropenia... 

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... 

The success of intravitreal implants, such as achieved with ganciclovir, has renewed interest in developing an intravitreal corticosteroid implant to further enhance the intravitreal route of administration, thus reducing the need for multiple injections. Bausch and Lomb and Control Delivery Systems have developed an intravitreal implant that can deliver the corticosteroid fluocinolone acetonide (Retrisert) to posterior eye tissue for up to 3 years. The implant, which was approved in 2005 by the U.S. Food and DrugAdministration (FDA), delivers 0.59 or 2.1 mg of fluocinolone acetonide. The long-term ocular side effects of this device are unknown at this time. 

The series of clinical trials that led to approval by the U.S. Food and Drug Administration involved 430 eyes in 330 patients. Fomivirsen significantly delayed progression of CMV retinitis in patients with AIDS, including those who had failed treatment with ganciclovir or foscarnet, the first-line therapies. Fomivirsen is administered by intravitreal injection at doses of 165 pg once weekly for three weeks of induction and then once every two weeks. It also can be administered In a dose of 330 pg on days 1 and 15 and then once a month thereafter. Mean maximum retinal concentrations of fomivirsen occur at 2 days, and the elimination half-life after a single, 115-pg dose in monkey retina was 78 hours. There are no systemic side effects. Ocular side effects include Increased intraocular pressure and mild to moderate intraocular inflammation that can be reversed with topical steroid treatment. It is important that side effects be minor, because treatment will be lifelong. 

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