The publication data currently available has been vetted by Vanderbilt faculty, staff, administrators and trainees. The data itself is retrieved directly from NCBI's PubMed and is automatically updated on a weekly basis to ensure accuracy and completeness.
If you have any questions or comments, please contact us.
Valacyclovir, the L-valyl ester prodrug of acyclovir (ACV), is widely prescribed to treat infections caused by varicella-zoster virus or herpes simplex virus. Rarely, treatment is complicated by reversible neuropsychiatric symptoms. By mechanisms not fully understood, this occurs more frequently in the setting of renal impairment. We characterized the steady-state pharmacokinetics of ACV and its metabolites 9-[(carboxymethoxy)methyl]guanine (CMMG) and 8-hydroxy-acyclovir (8-OH-ACV) in cerebrospinal fluid (CSF) and the systemic circulation. We administered multiple doses of high-dose valacyclovir to 6 subjects with normal renal function and 3 subjects with chronic renal impairment (creatinine clearance [CrCl], approximately 15 to 30 ml/min). Dosages were 2,000 mg every 6 h and 1,500 mg every 12 h, respectively. Indwelling intrathecal catheters allowed serial CSF sampling throughout the dosing interval. The average steady-state concentrations of acyclovir, CMMG, and 8-OH-ACV were greater in both the systemic circulation and the CSF among subjects with impaired renal function than among subjects with normal renal function. However, the CSF penetration of each analyte, reflected by the CSF-to-plasma area under the concentration-time curve over the 6- or 12-h dosing interval (AUC(tau)) ratio, did not differ based on renal function. Renal impairment does not alter the propensity for ACV or its metabolites to distribute to the CSF, but the higher concentrations in the systemic circulation, as a result of reduced elimination, are associated with proportionally higher concentrations in CSF.
BACKGROUND - Information is limited on long-term outcomes after preemptive use of ganciclovir to control cytomegalovirus (CMV) infection in lung transplantation.
METHODS - We studied 78 lung recipients who received antithymocyte globulin induction from 1994 to 2000. All patients received six months of oral acyclovir (800 mg TID). This was interrupted three wk post transplantation for a two-wk course of IV ganciclovir. Additional courses of ganciclovir were administered based on serial virological monitoring. CMV-mismatched patients (R-D+) also received four doses of CMV immunoglobulin between weeks 2 and 8.
RESULTS - The one yr cumulative risk of CMV disease was 2% (1/61) in CMV seropositive (R+) patients, but was 37% (6/17) in R-D+ patients (p < 0.0001). Over 4.3 yr of follow-up, patients with CMV infection developed more chronic graft dysfunction caused by bronchiolitis obliterans or bronchiolitis obliterans syndrome than patients without CMV infection (p = 0.012). This effect was also apparent in the subgroup of R+ recipients (p = 0.043). Acute rejection and overall survival were not associated with CMV infection.
CONCLUSIONS - The use of prophylactic acyclovir and short preemptive courses of ganciclovir effectively controlled CMV disease in R+ patients, but was a relative failure in R-D+ patients. CMV infection was significantly associated with chronic graft dysfunction, even in R+ recipients who had good control of CMV symptoms.
HSV causes serious complications in immunocompromised patients, especially SCT recipients. Although ACV is an effective antiviral prophylaxis, the emergence of ACV resistance is a growing problem. The authors describe two cases of fatal ACV-resistant HSV in two pediatric patients following unrelated donor SCT. Despite the in vitro sensitivity of the HSV isolates to foscarnet, both patients failed to respond to foscarnet therapy. Other antiviral therapies should be considered in those patients who fail to show rapid clinical improvement.
A retrospective single center study was performed to evaluate the safety and efficacy of valacyclovir for prevention of cytomegalovirus (CMV) infection (reactivation) after allogeneic stem cell transplantation (SCT). We compared a group of 31 patients at risk for CMV reactivation (donor, recipient or both seropositive for CMV) who received valacyclovir at an oral dose of 1 g three times a day for CMV prophylaxis with a matched cohort of 31 patients who did not receive the drug or any other form of CMV prophylaxis. Valacyclovir was used as primary prophylaxis in 12 patients and as secondary prophylaxis (after a prior CMV reactivation was effectively treated with either ganciclovir or foscarnet and without CMV antigenemia at the start of valacyclovir) in the remaining 19 patients. The two treatment groups were well matched for the donor-recipient CMV serological status and other pre-transplant characteristics. CMV reactivation was detected by blood antigenemia testing using a commercially available immunofluorescence assay for CMV lower matrix protein pp65 in circulating leukocytes. For primary prophylaxis, 3/12 patients who received valacyclovir reactivated CMV compared to 24/31 patients in the control group (P < 0.001). For secondary prophylaxis, 5/19 valacyclovir patients reactivated compared to 16/24 control patients (P < 0.05). Valacyclovir was well tolerated except for infrequent and mild gastrointestinal side-effects. There was no difference in the incidence of CMV disease in the two groups. Prophylaxis with valacyclovir appears to be safe and efficacious in preventing both primary and secondary CMV reactivation in at-risk patients after allogeneic SCT. Larger prospective randomized studies will be required to confirm these observations.
Nosocomial transmission of herpes simplex virus (HSV) has been described in intensive care units. A cluster of three patients with HSV wound infections within a 6-week period prompted temporary closure of a burn unit and suggested nosocomial cross infection. However, restriction endonuclease "fingerprint" analysis of the HSV isolates showed them to be genetically and therefore epidemiologically unrelated. This report describes these cases and the use of intravenous acyclovir in the treatment of HSV burn wound infections.
We review 15 cases of secondary B-cell lymphoproliferative disorders that occurred among 2,475 patients who received allogeneic bone marrow transplants (BMTs) at the Fred Hutchinson Cancer Research Center (Seattle) between 1969 and 1987. The histopathologic findings in 14 of the 15 patients spanned a wide spectrum of lymphoproliferative lesions. One patient had features characteristic of angioimmunoblastic lymphadenopathy. Epstein-Barr virus (EBV) genomic sequences were identified by Southern blot analysis in each of the 13 patients evaluated. Ten of the 12 lesions evaluated originated in donor cells. In two patients, who had mixed chimerism after transplantation, the lesions originated in host cells. The combined evidence from immunoglobulin light chain staining and the analysis of immunoglobulin heavy chain gene rearrangement indicated that the lesions in most patients represented polyclonal proliferations that gave rise to clonal subpopulations. The results indicate an overall actuarial incidence of 0.6% for this complication in BMT recipients. Anti-CD3 monoclonal antibody (MoAb) treatment of acute graft-v-host disease (GVHD) and T cell depletion of the donor marrow were statistically significant risk factors, and GVHD appeared to play a contributing role, particularly in the setting of human leukocyte antigen (HLA) disparity. Two patients had no identifiable risk factors. Prophylaxis or treatment with acyclovir had no detectable effect in the patients; all but two died with uncontrolled lymphoproliferation.