Drug of choice for cytomegalovirus –
**Core Concept**
Cytomegalovirus (CMV) is a member of the herpesvirus family that causes a range of diseases, from asymptomatic infection to severe congenital abnormalities and life-threatening complications in immunocompromised individuals. The treatment of CMV infection is critical to prevent disease progression.
**Why the Correct Answer is Right**
The drug of choice for treating CMV is ganciclovir, an antiviral medication that works by inhibiting viral DNA synthesis and replication. Ganciclovir is a nucleoside analog that competitively inhibits the viral DNA polymerase, preventing the virus from replicating. It is particularly effective against CMV and is commonly used in immunocompromised patients, such as those with HIV/AIDS or undergoing organ transplantation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because valacyclovir is primarily used to treat herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections, not CMV.
**Option B:** This option is incorrect because foscarnet is an alternative antiviral medication for treating CMV, but it is not the first-line treatment.
**Option C:** This option is incorrect because cidofovir is an antiviral medication used to treat cytomegalovirus retinitis in HIV/AIDS patients, but it is not the preferred treatment for CMV infection.
**Clinical Pearl / High-Yield Fact**
Ganciclovir is often administered intravenously to treat CMV infection, but oral valganciclovir is a commonly used alternative for patients who require long-term therapy.
**Correct Answer:** B. Foscarnet