Valtrex or valacyclovir
Neurotoxicity of valacyclovir in peritoneal dialysis: a pharmacokinetic study.

Deray G.

Department of Nephrology, Pitie-Salpetriere Hospital, Paris, France. hassan.izzedine psl.ap-hop-paris.fr

Valacyclovir is an effective oral agent for the treatment of herpes virus infection, however, the pharmacokinetics of the drug are altered in renal failure. It is increasingly recognized that dose adjustment of oral valacyclovir in renal failure is necessary to avoid neurotoxicity. We studied this drug in a continuous ambulatory peritoneal dialysis (CAPD) and immunocompromised patient. She developed neurotoxicity with an adjustment dosage of valacyclovir for a cutaneous zoster infection. The elimination half-time (15 h) was similar to that reported for end-stage renal disease patients, while the steady-state volume of distribution (85 l) and the area under the curve concentration (127 mg/l.h) were greater. The mean CAPD dialysance was only 5.27 ml/min with less than 1% of an administered dose being recovered in the 24-hour dialysate. 48 h after interrupting treatment, she recovered normal neurological status and 500 mg of valacyclovir every 2 days was effective and well tolerated. Copyright 2001 S. Karger AG, Basel

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Valtrex or valacyclovir
Recognition and transport characteristics of nonpeptidic compounds by basolateral peptide transporter in Caco-2 cells.

Inui K.

Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Kyoto University, Kyoto, Japan.

Recent studies have revealed that diverse compounds lacking peptide bonds, such as valacyclovir and delta-aminolevulinic acid (delta-ALA), can be recognized by H+-coupled peptide transporters (PEPT1 and PEPT2). In the present study, recognition and transport characteristics of nonpeptidic compounds by the basolateral peptide transporter, which is distinct from PEPTs, were compared with those by PEPT1 using the human intestinal Caco-2 cells. [14C]Glycylsarcosine uptake via PEPT1 was inhibited by all nonpeptidic compounds tested. Similarly, most nonpeptidic compounds showed an inhibitory effect on [14C]glycylsarcosine uptake by the basolateral peptide transporter, although some kinds of nonpeptidic compounds, such as valine methyl ester, did not. Direct measurements of valacyclovir and delta-ALA transport revealed that both compounds were able to be transported by the basolateral peptide transporter. Because delta-ALA has been used recently in vitro and in clinical studies as an endogenous photosensitizer for photodynamic therapy, the intestinal transport characteristics of delta-ALA were further examined. Inhibition studies and Eadie-Hofstee plot analysis suggested that delta-ALA transport across the brush-border and basolateral membranes of the intestine was mainly mediated by peptide transporters. In addition, the apical-to-basolateral transport of delta-ALA was greater than that of the opposite direction. These findings provide the first evidence that the intestinal basolateral peptide transporter can recognize and transport nonpeptidic compounds, and play a definitive role in the absorption of delta-ALA.

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Valtrex or valacyclovir
[Efficacy of cidofovir in an HIV infected patient with an acyclovir and foscarnet resistant herpes simplex virus infection]

[Article in French]

Saint-Leger E, Fillet AM, Malvy D, Rabanel B, Caumes E.

Service de Virologie CERVI (Professeur Huraux), Groupe Hospitalier Pitie-Salpetriere, Paris.

BACKGROUND: We report the case of an AIDS patient, whose persistant HSV2 ulceration was clinically and phenotypically resistant to acyclovir and foscarnet. Only five clinical isolates of simultaneous acyclovir and foscarnet resistance have been previously described. CASE REPORT: This patient, without history of opportunistic infection, was hospitalized for a recurrent scrotal ulceration resistant to several antiviral treatment such as acyclovir, valacyclovir or foscarnet. The CD4 count was stable at 150/mm(3) and the HIV viral load was below detection level. The last recurrence appeared rapidly under valacyclovir therapy which had been introduced after 65 days of foscarnet therapy. Thus, the patient received a new dose of foscarnet. After initial efficacy, the ulceration increased once again. HSV2 phenotypic determination was done and detected, at that time, a double resistance to acyclovir and foscarnet. Healing was obtained with intravenous cidofovir. DISCUSSION: Foscarnet and acyclovir resistance in an HSV2 isolate is rare. This report presents several particularities. First, whereas the earlier published patients with an acyclovir and foscarnet resistant strain were widely immunocompromised, this was not the case for our patient. Secondly, in contrast with most precedent observations in which acyclovir-resistant strain disappeared after foscarnet therapy, in our case the acyclovir resistant strain remained after foscarnet therapy. Finally, few reports concerned the clinical efficacy of cidofovir in HSV infection. In this case, we proved that intravenously cidofovir was highly and rapidly effective on acyclovir and foscarnet resistant strains.

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Valtrex or valacyclovir
Shingles (Herpes Zoster) and Post-herpetic Neuralgia.

King MK.

Departments of Neurology, Neuroscience, and Microbiology, New Mexico VA Health Care System, 1501 San Pedro Drive, SE, Albuquerque, NM 87108, USA. LEDavis UNM.edu

During childhood chickenpox, varicella-zoster virus becomes latent in neurons of the dorsal root or trigeminal ganglia. Shingles results years to decades later from a breakdown of viral latency within a ganglion and subsequent virus spread to the skin producing a unilateral dermatomal vesicular rash accompanied by segmental pain. Treatment with famciclovir, valacyclovir, and high dose acyclovir is beneficial if started within the first 3 days of the rash. All three drugs can be given orally, are equally effective, shorten the duration of viral shedding and time to healing of the rash by 1 to 2 days, and lessen the intensity and duration of the acute neuritic pain. Famciclovir and valacyclovir have more convenient dosing schedules (three times daily) compared to acyclovir (five times daily). Mild cases of shingles in younger healthy individuals often do not require any antiviral treatment. Pain in shingles may have burning, lancinating, or allodynic qualities, ranges in intensity from mild to unbearable, and lasts 2 to 8 weeks. Pain treatment varies on the type and intensity of pain experienced. In a few patients, post-herpetic neuralgia develops and the dermatomal pain persists for months to years. Effective treatment of post-herpetic pain is often difficult.

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Valtrex or valacyclovir
Valacyclovir inhibition of recovery of ocular herpes simplex virus type 1 after experimental reactivation by laser in situ keratomileusis.

Gordon YJ.

Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15203, USA. dhaliwaldk msx.upmc.edu

PURPOSE: To determine whether the systemic administration of valacyclovir (Valtrex) reduces ocular shedding of herpes simplex virus type 1 (HSV-1) after laser in situ keratomileusis (LASIK) in the New Zealand White (NZW) rabbit latency model. SETTING: Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA. METHODS: New Zealand White rabbits latently infected with HSV-1 W strain were divided into 3 groups. The first received 100 mg/kg/day of valacyclovir; the second, 200 mg/kg/day of valacyclovir; and the third (control), saline. One half the total dose of valacyclovir was delivered via intraperitoneal injections twice daily for 7 days beginning with 1 dose before LASIK. The HSV-1 ocular shedding was determined from eye cultures for 7 days after LASIK. RESULTS: The administration of both 100 mg/kg/day and 200 mg/kg/day of valacyclovir significantly reduced the number of eyes (1/16 in both groups) and the total number of HSV-1 shedding days (1/122 and 2/122, respectively) from which HSV-1 was recovered compared to the control group (7/16 [P =.0396] and 14/129 [P <.007], respectively). CONCLUSIONS: Systemic administration of valacyclovir significantly reduced HSV-1 ocular shedding after LASIK in the NZW rabbit latency model. The clinical implications of this study suggest that patients with a history of recurrent ocular herpes may be able to safely have LASIK with less risk of a recurrent herpetic episode while on valacyclovir antiviral prophylaxis.

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Valtrex or valacyclovir
Valacyclovir for the prevention of cytomegalovirus infection after allogeneic stem cell transplantation: a single institution retrospective cohort analysis.

Goodman SA.

Division of Hematology and Oncology, Department of Medicine, Vanderbilt University School of Medicine and VA Medical Center, Nashville, TN 37212, USA.

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.

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Valtrex or valacyclovir
Valacyclovir for the prevention of cytomegalovirus disease after renal transplantation. International Valacyclovir Cytomegalovirus Prophylaxis Transplantation Study Group.

Lee IC.

Department of Internal Medicine, Piedmont Hospital, Atlanta, GA 30367, USA. dlowa80715 aol.com

BACKGROUND: Cytomegalovirus (CMV) disease is a major complication of organ transplantation. We hypothesized that prophylactic treatment with valacyclovir would reduce the risk of CMV disease. METHODS: A total of 208 CMV-negative recipients of a kidney from a seropositive donor and 408 CMV-positive recipients were randomly assigned to receive either 2 g of valacyclovir or placebo orally four times daily for 90 days after transplantation, with the dose adjusted according to renal function. The primary end point was laboratory-confirmed CMV disease in the first six months after transplantation. RESULTS: Treatment with valacyclovir reduced the incidence or delayed the onset of CMV disease in both the seronegative patients (P<0.001) and the seropositive patients (P=0.03). Among the seronegative patients, the incidence of CMV disease 90 days after transplantation was 45 percent among placebo recipients and 3 percent among valacyclovir recipients. Among the seropositive patients, the respective values were 6 percent and 0 percent. At six months, the incidence of CMV disease was 45 percent among seronegative recipients of placebo and 16 percent among seronegative recipients of valacyclovir; it was 6 percent among seropositive placebo recipients and 1 percent among seropositive valacyclovir recipients. At six months, the rate of biopsy-confirmed acute graft rejection in the seronegative group was 52 percent among placebo recipients and 26 percent among valacyclovir recipients (P=0.001). Treatment with valacyclovir also decreased the rates of CMV viremia and viruria, herpes simplex virus disease, and the use of inpatient medical resources. Hallucinations and confusion were more common with valacyclovir treatment, but these events were not severe or treatment-limiting. The rates of other adverse events were similar among the groups. CONCLUSIONS: Prophylactic treatment with valacyclovir is a safe and effective way to prevent CMV disease after renal transplantation.

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