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What is Ganciclovir and explain in detail?
Ganciclovir, sold under the brand name Cytovene among others, is an antiviral medication used to treat cytomegalovirus (CMV) infections.
Ganciclovir was patented in 1980 and approved for medical use in 1988.

Medical use
Ganciclovir is indicated for:
Sight-threatening CMV retinitis in severely immunocompromised people
CMV pneumonitis in bone marrow transplant recipients
Prevention of CMV disease in bone marrow and solid organ transplant recipients
Confirmed CMV retinitis in people with AIDS (intravitreal implant)It is also used for acute CMV colitis in HIV/AIDS and CMV pneumonitis in immunosuppressed patients.Ganciclovir has also been used with some success in treating Human herpesvirus 6 infections.Ganciclovir has also been found to be an effective treatment for herpes simplex virus epithelial keratitis.

Adverse effects
Ganciclovir is commonly associated with a range of serious haematological adverse effects. Common adverse drug reactions (≥1% of patients) include: granulocytopenia, neutropenia, anaemia, thrombocytopenia, fever, nausea, vomiting, dyspepsia, diarrhea, abdominal pain, flatulence, anorexia, raised liver enzymes, headache, confusion, hallucination, seizures, pain and phlebitis at injection site (due to high pH), sweating, rash, itch, increased serum creatinine and blood urea concentrations.

Toxicity
Ganciclovir is considered a potential human carcinogen, teratogen, and mutagen. It is also considered likely to cause inhibition of spermatogenesis. Thus, it is used judiciously and handled as a cytotoxic drug in the clinical setting.

Mechanism of action
Ganciclovir is a synthetic analogue of 2′-deoxy-guanosine. It is first phosphorylated to ganciclovir monophosphate by a viral kinase encoded by the cytomegalovirus (CMV) gene UL97 during infection. Subsequently, cellular kinases catalyze the formation of ganciclovir diphosphate and ganciclovir triphosphate, which is present in 10-fold greater concentrations in CMV or herpes simplex virus (HSV)-infected cells than uninfected cells.
Ganciclovir triphosphate is a competitive inhibitor of deoxyguanosine triphosphate (dGTP) incorporation into DNA and preferentially inhibits viral DNA polymerases more than cellular DNA polymerases