Antiviral Drugs Quiz

Antiviral Drugs for CMV, Adenovirus, BK Virus, Hepatitis A and B

• Foscarnet is a non-nucleoside pyrophosphate analog that inhibits viral DNA polymerase and reverse transcriptase. It is effective against HSV, HHV-6, VZV, EBV, and CMV.
• Cidofovir is a nucleotide analogue of cytosine that inhibits viral DNA synthesis. It is effective against resistant forms of HSV, CMV, HHV6, BKV, Adenovirus, Ebola, and anthrax.
• Cytomegalovirus (CMV) is the most common viral infection in infants born in the US. It can cause permanent disabilities and is often transmitted from pregnant women to their infants.
• Ganicyclovir is a guanosine analogue that is 10 times more active against CMV than acyclovir. It is used for prophylaxis and treatment of CMV in organ transplant patients.
• Letermovir inhibits CMV DNA terminase and is effective only against CMV. It has high bioavailability and can be given orally or intravenously.
• Maribavir inhibits UL97 kinase and has a multimodal effect on CMV DNA replication. It is available only orally and is metabolized by CYP3A4.
• CMV drug resistance can occur due to mutations in UL97 or UL54 genes. Active drugs against resistant CMV strains include cidofovir, foscarnet, letermovir, and maribavir.
• Adenovirus infections are often seen in solid organ transplant and hematopoietic stem cell transplant patients. Cidofovir is the drug of choice for treatment, administered with probenecid to decrease nephrotoxicity.
• BK virus can cause hemorrhagic cystitis/nephropathy in immunocompromised patients. Treatment involves reducing immunosuppression and using intravenous cidofovir or intravesicular cidofovir.
• Hepatitis A is an RNA virus transmitted fecally, orally, or sexually. It causes mild jaundice and self-resolves without treatment. Prevention is possible with the HepA vaccine.
• Hepatitis B is a chronic infection that can lead to liver damage. Antiviral treatment options include tenofovir, entecavir, and lamivudine, with varying efficacy, resistance barriers, and safety profiles.
• Tenofovir has potent activity against HBV but may cause renal and bone complications. Entecavir is highly effective but has a high cost. Lamivudine has a lower resistance barrier but is relatively safe.
• Interferon-alpha has an unacceptable safety profile for long-term treatment of HBV.