Treatment of CMV Enteritis
Initiate intravenous ganciclovir 5 mg/kg twice daily immediately for 3-5 days, then transition to oral valganciclovir 900 mg twice daily to complete a total treatment duration of 21-28 days or until complete symptom resolution. 1, 2
Initial Treatment Approach
Start with IV ganciclovir for rapid therapeutic drug levels, particularly in immunocompromised patients where CMV enteritis represents serious mucosal disease requiring aggressive systemic treatment similar to CMV esophagitis. 3, 1 The intravenous route ensures adequate drug delivery during the critical initial phase when gastrointestinal absorption may be compromised by mucosal inflammation. 2
Transition to Oral Therapy
After 3-5 days of IV therapy and once clinical improvement is observed with assured gastrointestinal absorption, switch to oral valganciclovir 900 mg twice daily. 3, 1, 2 This transition is appropriate when:
- Symptoms are improving
- Patient can tolerate oral medications
- No evidence of severe malabsorption 3
Continue the oral phase to complete 21-28 days total treatment or until complete resolution of signs and symptoms. 3, 1
Patient-Specific Considerations
HIV-Infected Patients
Initiate or optimize antiretroviral therapy concurrently with CMV treatment. 3 Continue CMV therapy until immune recovery occurs, defined as CD4+ count >100 cells/µL sustained for 3-6 months. 4, 3 Chronic maintenance therapy is not routinely recommended for gastrointestinal CMV disease but should be considered if relapses occur. 4
Transplant and Other Immunosuppressed Patients
Reduce immunosuppression if clinically feasible while treating CMV enteritis. 3 Monitor CMV viral load weekly by PCR to assess treatment response. 3
Immunocompetent Patients
Even elderly immunocompetent patients can develop CMV enteritis and respond to standard ganciclovir therapy, though this presentation is rare. 5, 6 The same treatment regimen applies, though duration may be shorter if immune function is intact.
Alternative Agents for Intolerance or Resistance
Foscarnet 90 mg/kg twice daily is the primary alternative for patients with ganciclovir intolerance or resistance. 2 This requires strict monitoring of renal function and electrolytes due to significant nephrotoxicity risk. 3, 2
Cidofovir may be considered as third-line therapy but carries substantial nephrotoxicity risk and should be reserved for refractory cases. 4, 2
Monitoring Requirements
During Induction Phase (First 3-5 Days)
Monitor twice weekly: 3
- Complete blood count (neutropenia and thrombocytopenia are dose-limiting toxicities)
- Serum creatinine and electrolytes
- Clinical symptom assessment
During Maintenance Phase
Monitor weekly: 3
- Complete blood count
- Renal function
- CMV viral load by PCR
- Clinical response
Critical Diagnostic Pitfalls to Avoid
Tissue biopsy with histopathology showing characteristic CMV intranuclear and intracytoplasmic inclusions is the gold standard for diagnosis. 3, 2 Positive CMV culture alone is insufficient, as immunocompromised patients may have asymptomatic viral shedding without true disease. 3, 2 Immunohistochemistry using monoclonal antibodies against CMV may be necessary when routine hematoxylin-eosin staining fails to reveal inclusion bodies. 5
Expected Adverse Effects
Ganciclovir/valganciclovir commonly causes: 3, 1
- Myelosuppression (neutropenia, anemia, thrombocytopenia) - most common and dose-limiting
- Nausea and diarrhea
- Renal dysfunction
Dose reduction or interruption may be necessary in up to 40% of patients due to hematologic toxicity. 1 If severe neutropenia develops (ANC <500 cells/µL), temporary interruption of antiviral therapy may be required.
Special Circumstances
For sight-threatening CMV retinitis occurring concurrently with enteritis, combination therapy with ganciclovir and foscarnet may be considered. 1 However, for isolated gastrointestinal disease, monotherapy with ganciclovir/valganciclovir is standard. 4, 1
Valganciclovir should not be used in patients with severe hepatic dysfunction, particularly liver transplant patients, where IV ganciclovir is preferred due to lower rates of CMV disease progression. 1