What is the treatment for cytomegalovirus (CMV) infection?

Treatment of Cytomegalovirus (CMV) Infection

The first-line treatment for CMV infection is ganciclovir 5 mg/kg IV twice daily for 2-3 weeks, with the option to switch to oral valganciclovir 900 mg twice daily after 3-5 days if clinical improvement occurs. 1, 2

Treatment Options Based on Patient Population

Immunocompromised Patients

First-Line Therapy:

• Induction therapy:

  • Ganciclovir: 5 mg/kg IV twice daily for 2-3 weeks 2, 1
  • OR Valganciclovir: 900 mg PO twice daily for 2-3 weeks (if oral intake is possible) 1, 3

• Maintenance therapy:

  • Following induction treatment: Valganciclovir 900 mg PO once daily 3
  • For HIV patients: Continue until immune recovery occurs (CD4+ count >100 cells/μL for 3-6 months) 1

Alternative Therapy (for ganciclovir resistance or intolerance):

• Foscarnet: 60 mg/kg IV every 8 hours or 90 mg/kg IV every 12 hours for 2-3 weeks 2, 1
• Cidofovir: For refractory cases 1
• Maribavir: 400 mg twice daily for resistant infections 1

Combination Therapy:

• For severe cases (especially CNS involvement): Combination of ganciclovir (5 mg/kg IV every 12 h) and foscarnet (60 mg/kg IV every 8 h or 90 mg/kg IV every 12 h) for 3 weeks 2
  • This combination has shown improvement or stabilization in 74% of patients with CMV encephalitis or myelitis 2

Specific Clinical Scenarios

CMV Retinitis:

• Induction: Valganciclovir 900 mg PO twice daily for 21 days 3
• Maintenance: Valganciclovir 900 mg PO once daily 3
• Regular ophthalmologic monitoring is essential 1

CMV Prevention in Transplant Recipients:

• Heart/kidney-pancreas transplant: Valganciclovir 900 mg PO once daily for 100 days post-transplantation 3
• Kidney transplant: Valganciclovir 900 mg PO once daily for 200 days post-transplantation 3
• Pediatric heart transplant (4 months to 16 years): Dose based on body surface area and creatinine clearance 3

CMV in Immunocompetent Adults:

• Targeted antiviral therapy with ganciclovir or valganciclovir is appropriate for severe disease 4
• Most cases are self-limiting and may only require symptomatic treatment 5

Monitoring During Treatment

1. Laboratory Monitoring:

   • Complete blood counts twice weekly during induction therapy and once weekly thereafter 1
   • Serum electrolytes twice weekly 1
   • Renal function regularly, especially with foscarnet therapy 1

2. Clinical Monitoring:

   • For CMV retinitis: Ophthalmologic examination at diagnosis, after completion of induction therapy, 1 month after initiation, and monthly thereafter 1
   • For CMV encephalitis: Regular neurological assessment

Adverse Effects to Monitor

• Ganciclovir/Valganciclovir: Neutropenia, thrombocytopenia, anemia, renal dysfunction 1, 3
• Foscarnet: Nephrotoxicity, electrolyte abnormalities (particularly calcium and phosphate), seizures 1
• Cidofovir: Nephrotoxicity, neutropenia 1

Special Considerations

1. Patients with renal impairment:

   • Dose adjustment required for both ganciclovir and valganciclovir 3
   • For patients on hemodialysis (CrCl <10 mL/min), valganciclovir should not be used 3

2. Patients with gastrointestinal involvement:

   • Intravenous therapy preferred over oral valganciclovir 1

3. Congenital CMV infection:

   • Valganciclovir treatment in symptomatic newborns can reduce hearing loss and improve long-term brain development 6

4. CNS involvement:

   • Combination therapy with ganciclovir and foscarnet is recommended due to poor penetration of ganciclovir alone into the CSF 2, 7
   • Consider delaying antiretroviral therapy in HIV patients until clinical improvement occurs to avoid inflammatory reactions 1

Treatment Failure Management

If clinical improvement is not observed after 7-14 days of initial therapy:

• For patients on ganciclovir: Switch to foscarnet or add foscarnet 2
• For patients on foscarnet: Switch to ganciclovir or add ganciclovir 2
• Consider resistance testing if available
• Always attempt to decrease immunosuppression whenever possible 2

The prognosis for CMV disease varies significantly based on the patient's immune status, with immunocompromised patients having poorer outcomes despite appropriate therapy 7. Early diagnosis and prompt initiation of treatment are crucial for improving outcomes.