Zirgan Ganciclovir Ophthalmic Gel 0.15% Sterile, 5 Gram Tube (RX)

Zirgan is a brand name for Ganciclovir ophthalmic gel, a medication used for the treatment of certain viral eye infections. It is a sterile gel formulation that contains 0.15% ganciclovir as the active ingredient. Ganciclovir is an antiviral medication that works by preventing the replication of certain viruses, including herpes simplex virus type 1 and 2, and cytomegalovirus. Zirgan is specifically indicated for the treatment of herpes simplex keratitis, a viral infection of the cornea (the clear layer at the front of the eye). It is available as a prescription medication to be applied directly to the eye.

Zirgan Ganciclovir Ophthalmic Gel 0.15% contains the active ingredient ganciclovir, which is an antiviral medication. It works by blocking the reproduction of certain viruses, specifically herpes viruses that can cause eye infections. The gel is applied directly to the surface of the eye, where it penetrates the cells and targets the viruses causing the infection. This helps to stop the spread of the virus and can slow down or stop the progression of the infection. By preventing the virus from replicating, Zirgan can also help to reduce symptoms such as eye pain, redness, and swelling, and promote healing of any existing sores or lesions on the eye.

It does this by interfering with the viral DNA polymerase enzyme, which is necessary for the viruses to replicate and spread. 
This prevents the virus from multiplying and spreading to new cells, allowing the body's natural immune system to fight off the infection. 
In the case of Zirgan, it primarily targets the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), which can cause eye infections or keratitis. 
Zirgan does not cure the infection, but it helps to reduce the severity and duration of symptoms, and may also prevent future outbreaks of the virus.