Valtrex : Order Valtrex Herpes Medicine

Order VALTREX - USA Pharmacy

Molecular mechanisms on drug transporters in the drug absorption and disposition

The membrane transport processes of drugs are critical issues to determine their absorption, distribution and elimination. Recently, various drug transporters have been identified and characterized. The enterocyte peptide transporter PEPT1 mediates the absorption of peptide-like drugs including beta-lactam antibiotics as well as Valacyclovir ( Valtrex ) lacking peptide bond. In the kidney, the basolateral organic anion transporters (OAT1, OAT3) and cation transporters (OCT1, OCT2) mediate renal distribution of hydrophilic anionic and cationic drugs, respectively. The brush-border type OAT-K1/K2 were suggested to be a target transporter for methotrexate-leucovorine rescue therapy. The ATP-driven efflux pump P-glycoprotein appeared to be an interaction site between digoxin and clarithromycin or itraconazole in the kidney. In addition, the intestinal P-glycoprotein was suggested to act as an absorptive barrier for tacrolimus in recipients of liver and small bowel transplantation.


Antiviral agents in women's health: pharmacotherapeutics of treating influenza and herpes.

This article updates the practitioner on the pharmacology of antiviral agents. The mechanism of action of the six different classifications of antiviral agents is described. Because influenza and herpes are the viral infections that are most frequently treated in clinical practice, the pharmacotherapeutics of common antiviral agents for these infections are described. This includes pharmacokinetics, adverse effects, preparations, and dosages. Other recommendations related to prescribing and client education surrounding each of the pharmaceutical agents is reviewed.


The effect of Valacyclovir ( Valtrex ) treatment on natural killer cells of infertile women.

PROBLEM: The aim of this study was to investigate the effect of Valacyclovir ( Valtrex ) treatment on natural killer (NK) cell concentration in the peripheral blood of infertile women. METHOD OF STUDY: Peripheral blood NK cell concentration of 104 non-pregnant women with a history of infertility was determined by flow cytometry. The controls were 14 fertile non-pregnant women. A cohort of 42 out of 104 women--whose NK cell levels were 175/microL or higher--was prospectively studied for the presence of HSV-1, 2, VZV, cytomegalovirus, HHV-6, HHV-7 and HHV-8 DNA in the peripheral blood and was orally administered Valacyclovir ( Valtrex ) (open label study). RESULTS: Herpes virus DNA was detected in 64.3% of the 42 women examined. Prior to Valacyclovir ( Valtrex ) treatment mean NK cell concentration in herpes-negative group was statistically higher from control group but lower from herpes positive group (P = 0.0007, ANOVA). Following Valacyclovir ( Valtrex ) treatment the mean NK cell concentration was statistically decreased in all studied women (P = 0.000453), in herpes-negative (P = 0.01622) and in herpes positive group (P = 0.0056). Sufficient decrease was observed in 31 (73.8%) of 42 women who received the drug. CONCLUSIONS: Valacyclovir ( Valtrex ) treatment is associated with a decrease of NK cell levels in most of the women with a history of infertility.


Valacyclovir ( Valtrex ) for prevention of recurrent herpes labialis: 2 double-blind, placebo-controlled studies.

The oral antiviral Valacyclovir ( Valtrex ), which is 3 to 5 times more bioavailable than its parent compound Acyclovir / Aciclovir, is a good candidate for effective therapy to suppress recurrent herpes labialis lesions. The efficacy of oral Valacyclovir ( Valtrex ) in the suppression of herpes labialis has not previously been reported. Two identical, randomized, double-blind, parallel-group studies were conducted to evaluate the efficacy of oral Valacyclovir ( Valtrex ) 500 mg (n=49) versus placebo (n=49) once daily for 16 weeks in the suppression of herpes labialis among patients with a history of 4 or more recurrent lesions in the previous year. Data from the studies were pooled for analysis. Twenty-eight patients (60%) in the Valacyclovir ( Valtrex ) group compared with only 18 patients (38%) in the placebo group were recurrence-free throughout the 4-month treatment period (P=.041). The mean time to first recurrence was significantly longer with Valacyclovir ( Valtrex ) (13.1 weeks) compared with placebo (9.6 weeks) (P=.016). The total number of recurrences in patients using Valacyclovir ( Valtrex ) was 24 compared with 41 in patients using placebo. The incidence of adverse events during the 4-month treatment period was slightly lower in the Valacyclovir ( Valtrex ) group (22 events, 33% of patients) compared with the placebo group (29 events, 39% of patients). The results of these small double-blind, placebo-controlled studies suggest that oral Valacyclovir ( Valtrex ) 500 mg once daily for 4 months is effective and well tolerated for the prevention of recurrent herpes labialis. More research with larger patient numbers is warranted to corroborate and extend these findings.


New therapies and prevention strategies for genital herpes.

genital herpes is among the most prevalent sexually transmitted diseases. Optimal management of genital herpes includes accurate diagnosis, antiviral therapy, and counseling of patients about complications and transmission of herpes simplex virus (HSV). Antiviral therapy offers significant palliation, and the option of episodic or suppressive treatment should be offered to all patients with genital herpes. Valacyclovir ( Valtrex ) and Famciclovir ( Famvir ) are two newer antiviral agents that are effective and safe for the treatment of genital herpes. Prevention strategies for sexual and perinatal transmission of HSV have not been well defined. Availability of type-specific serological tests for HSV antibodies may assist in identifying persons at risk for acquiring or transmitting HSV infection. Further research is needed to define strategies to prevent the spread of this epidemic infection.


The mild encephalitis-hypothesis--new findings and studies

Causes and pathogenesis of psychiatric disorders is poorly understood. Infections by viruses or other agents may disturb neurotransmitters and elicit behavioral abnormalities, and induce long lasting immune reactions, referred to as mild encephalitis (ME). New findings (pathology, biochemistry, imaging) in schizophrenia and bipolar psychoses are compatible with ME hypothesis. In Chorea Sydenham and PANDAS syndrome autoimmune ME seems to explain anxiety-compulsive-hyperactivity symptoms. Add-on-therapy with Cox-II-blockers or Valacyclovir ( Valtrex ) improved acute schizophrenia, CSF filtration some cases of therapy resistant psychoses.


Once-daily Valacyclovir ( Valtrex ) hydrochloride for suppression of recurrent genital herpes.

OBJECTIVE: To document the frequency of genital herpes recurrences in men and women with histories of recurrent genital herpes during 1 year of continuous, suppressive therapy with Valacyclovir ( Valtrex ) hydrochloride (HCl). METHODS: In an open-label clinical trial conducted at 11 centers, 127 subjects (46 women and 81 men) with histories of recurrent genital herpes (at least 6 recurrences per year) were treated with Valacyclovir ( Valtrex ) HCl (500 mg once daily), and their clinical status was followed up for 1 year. genital herpes recurrences were documented in diaries, and quarterly clinic visits were made for evaluating lesion recurrences and drug safety. In cases of recurrence, subjects self-treated with Valacyclovir ( Valtrex ) HCl 500 mg twice daily for 5 days, then resumed once-daily treatment. RESULTS: After the first 3 months of suppressive therapy, 81% of subjects were free of recurrence. Recurrence-free rates remained undiminished during the second, third, and fourth quarters (84%, 84%, and 91%, respectively) and were similar for men and women. Thirty of 46 women (65%) and 56 of 81 men (69%) remained recurrence free during the study and therapy was well tolerated. Adverse events were mild, infrequent, and not considered related to the study drug. CONCLUSION: Valacyclovir ( Valtrex ) HCl was highly effective and well tolerated as continuous suppressive therapy in men and women with recurrent genital herpes. Potential benefits of the once-daily regimen of Valacyclovir ( Valtrex ) HCl include improved patient compliance.


Recognition of L-amino acid ester compounds by rat peptide transporters PEPT1 and PEPT2.

Peptide transporters (PEPT1 and PEPT2) in epithelia play an important role in the absorption of small peptides and peptide-like drugs. Recently, it was demonstrated that various nonpeptidic compounds can be transported by these transporters. In the present study, we focused on the L-amino acid ester compounds and examined the mechanisms of their interaction with rat PEPTs (rPEPTs) using stable transfectants. Valacyclovir ( Valtrex ), the L-valyl ester prodrug of the antiherpetic agent Acyclovir / Aciclovir, competitively inhibited [(14)C]glycylsarcosine uptake in the rPEPT1- or rPEPT2-expressing cells. Dixon plot analyses showed that the inhibition constant (K(i)) values of Valacyclovir ( Valtrex ) were 2.7 and 0.22 mM for rPEPT1 and rPEPT2, respectively, suggesting that rPEPT2 had higher affinity for this agent. Various L-valine alkyl esters significantly inhibited [(14)C]glycylsarcosine uptake. L-Valine methyl ester (Val-OMe) competitively inhibited [(14)C]glycylsarcosine uptake with K(i) values of 3.6 and 0.83 mM for rPEPT1 and rPEPT2, respectively, indicating that Val-OMe is also a high-affinity substrate for rPEPT2. Val-OMe had a trans-stimulation effect on [(14)C]glycylsarcosine efflux from both transfectants, suggesting the translocation of L-valine methyl ester via rPEPTs. Val-OMe showed the most potent inhibitory effect among the several L-amino acid methyl esters examined. We conclude that Val-OMe, as well as Valacyclovir ( Valtrex ), could be recognized and transported by rPEPT1 and rPEPT2 and that these L-valyl esters showed higher affinity for rPEPT2 as do most substrates of these transporters. Our results suggest that L-valine is a desirable L-amino acid for the esterification of poorly permeable drugs to enhance their oral bioavailability targeting intestinal PEPT1.


HSV shedding.

Viral shedding of HSV occurs frequently in infected individuals. HSV is shed asymptomatically from multiple anatomical sites and shedding, like exposure, is a significant risk for transmission. However, the relationship between shedding frequency, viral titer and transmission is unknown. HSV-2 shedding is affected by the site and time since acquisition of infection. The advent of sensitive PCR techniques has shown that the magnitude and frequency of viral shedding is higher than shown previously with viral culture techniques. It has also clearly demonstrated that suppressive (daily) antiviral therapy reduces clinical and subclinical reactivation rates, and has been successfully used in the prevention of recurrent oral and genital HSV infections. A recent study has demonstrated that daily antiviral therapy with valAcyclovir / Aciclovir can significantly reduce transmission of HSV-2 between discordant heterosexual couples in monogamous relationships.


A novel nucleoside prodrug-activating enzyme: substrate specificity of biphenyl hydrolase-like protein.

Biphenyl hydrolase-like protein is a novel human serine hydrolase recently identified as a human Valacyclovir ( Valtrex )ase, catalyzing the hydrolytic activation of the antiviral prodrugs Valacyclovir ( Valtrex ) and valganciclovir. The substrate specificity of BPHL was investigated with a series of amino acid ester prodrugs of the therapeutic nucleoside analogues: Acyclovir / Aciclovir, zidovudine, floxuridine, 2-bromo-5,6-dichloro-1-(beta-D-ribofuranosyl) benzimidazole, and gemcitabine. The hydrolysis of typical esterase and aminopeptidase substrates by BPHL was also investigated. The results indicate that the substrate specificity of BPHL is largely determined by the amino acid acyl promoiety, and is less sensitive to the nucleoside parent drugs. For all nucleoside parent drugs, BPHL preferred the hydrophobic amino acids valine, phenylalanine, and proline over the charged amino acids lysine and aspartic acid. The position and monoester or diester form of the prodrug were also important, with BPHL exhibiting higher affinity for the 5'-esters than for the 3'-esters and the 3',5'-diesters irrespective of amino acid type. Further, the presence of the 3'-amino acid ester considerably reduced the hydrolysis rate of the 5'-amino acid ester functionality. BPHL exhibited stereoselectivity with an L/D specificity ratio of 32 for 5'-valyl floxuridine and 1.5 for 5'-phenylalanyl floxuridine. The substrate specificity suggests that the substrate-binding pocket of BPHL has a hydrophobic acyl binding site which can accommodate the positively charged alpha-amino group, while having an alcohol leaving group binding site that can accommodate nucleoside analogues with a relatively generous spatial allowance. In conclusion, BPHL catalyzes the hydrolytic activation of amino acid esters of a broad range of therapeutic nucleoside analogues in addition to Valacyclovir ( Valtrex ) and valganciclovir and has considerable potential for utilization as an activation target for design of antiviral and anticancer nucleoside analogue prodrugs.


The effectiveness of Valacyclovir ( Valtrex ) in preventing reactivation of herpes gladiatorum in wrestlers.

OBJECTIVE: To determine whether nucleoside analogues can suppress recurrent outbreaks of herpes simplex virus type 1 (HSV-1) in wrestlers, commonly called herpes gladiatorum. DESIGN: Double-blind and open study using Valacyclovir ( Valtrex ) over two wrestling seasons from 1996 through 1998. SETTING: Wrestling community in the Minneapolis-St. Paul area of Minnesota. PARTICIPANTS: Volunteer sample of 42 male wrestlers from 13 to 31 years of age. For inclusion, patients had to have recurrent herpes gladiatorum and be active in a wrestling program. INTERVENTION: Participants were treated during the first half of the season in a double-blind study using Valacyclovir ( Valtrex ) 500 mg a day, and in the second half as an open study with all wrestlers using Valacyclovir ( Valtrex ) 1,000 mg. MAIN OUTCOME MEASURES: Outbreak of herpes gladiatorum based on clinical appearance or culture. RESULTS: Participants were divided into two groups based on time interval since primary outbreak of herpes gladiatorum: less than 2 years or more than 2 years. For patients in whom primary outbreak was less than 2 years ago, outbreaks occurred in 21% (3/14) of those receiving Valacyclovir ( Valtrex ) 500 mg per day and 8% (2/25) of those receiving Valacyclovir ( Valtrex ) 1,000 mg per day. For patients in whom primary outbreak was more than 2 years ago, outbreaks occurred in 0% (0/7) of those receiving Valacyclovir ( Valtrex ) 500 mg per day and 0% (0/12) of those receiving Valacyclovir ( Valtrex ) 1,000 mg per day. CONCLUSION: For patients with a history of herpes gladiatorum of more than 2 years, Valacyclovir ( Valtrex ) 500 mg daily suppresses recurrent outbreaks. Further studies need to be performed to determine proper dosing regimen for suppression of outbreaks in patients with a disease duration of less than 2 years.


ValAcyclovir / Aciclovir (BW256U87): the L-valyl ester of Acyclovir / Aciclovir.

ValAcyclovir / Aciclovir (BW256U87) is an L-valyl ester of Acyclovir / Aciclovir, which is extensively and almost completely converted to Acyclovir / Aciclovir. In healthy human volunteers, single valAcyclovir / Aciclovir doses of 100-1000 mg resulted in dose-proportional increases in Acyclovir / Aciclovir area under the curve (AUC). The 1,000 mg dose produced an Acyclovir / Aciclovir peak plasma concentration (Cmax) of 5-6 micrograms/ml, AUC6 of 19 hr. micrograms/ml, time to maximum plasma concentration (Tmax) of 1-2 hr, and half-life (T1/2) of 2.8 hr. Plasma valAcyclovir / Aciclovir peak levels were < 0.3 micrograms/ml, and the prodrug was undetectable after 3 hr. Multiple valAcyclovir / Aciclovir doses of 250-2,000 mg given four times daily for 10 days resulted in dose-proportional increases in Acyclovir / Aciclovir Cmax. There were less than proportional increases in the AUCs. No serious or unexpected adverse events or laboratory abnormalities were reported. In volunteers with advanced human immunodeficiency virus (HIV) disease (absolute CD4 lymphocyte count < 150 cells/microliters), Acyclovir / Aciclovir and valAcyclovir / Aciclovir pharmacokinetic results were nearly identical to those in healthy volunteers. At the 2 g dose administered four times daily, steady-state Acyclovir / Aciclovir Cmax = 8.4 micrograms/ml, Tmax = 2.0 hr, AUC6 = 30.5 hr. micrograms/ml, and T1/2 = 3.3 hr. Nausea, vomiting, diarrhoea, and abdominal pain were commonly reported; however, only one adverse event (diarrhoea) was causally linked to valAcyclovir / Aciclovir exposure. There were no renal or neurologic adverse events. ValAcyclovir / Aciclovir is well absorbed and is rapidly converted to Acyclovir / Aciclovir, resulting in three- to fourfold higher Acyclovir / Aciclovir levels than can be achieved with oral Acyclovir / Aciclovir, even in patients with advanced HIV disease. The safety profile is generally favourable, with no evidence of nephrotoxicity or neurotoxicity.


A double-blind, randomized study assessing the equivalence of Valacyclovir ( Valtrex ) 1000 mg once daily versus 500 mg twice daily in the episodic treatment of recurrent genital herpes. Genival Study Group.

ValAcyclovir / Aciclovir is a prodrug of Acyclovir / Aciclovir with more favourable bioavailability. Twice daily oral administration of Valacyclovir ( Valtrex ) is recommended in patients with genital herpes. A double-blind, randomized, controlled, multicriteria equivalence trial was conducted to determine whether od treatment with Valacyclovir ( Valtrex ) 1000 mg is as effective as bd treatment with 500 mg in patients with recurrent genital herpes. A total of 922 immunocompetent outpatients were treated with either regimen for 5 days; treatment was self-initiated at the first symptoms of the next recurrence. The principal outcome measures were the percentage of lesions healed at day 6, time to healing, time to cessation of pain, discomfort or itching, the percentage of abortive episodes and safety. Equivalence was assessed by comparison of 80% confidence limits for each measure; the two regimens were regarded as equivalent if the lower confidence limit was higher than a pre-determined equivalence limit calculated to show a maximum 10% inferiority of Valacyclovir ( Valtrex ) 1000 mg od against valAcyclovir / Aciclovir 500 mg bd. Intention-to-treat analysis showed that the two treatments were equivalent for each outcome measure. Hence, it is concluded that Valacyclovir ( Valtrex ) 1000 mg od is as effective as 500 mg bd. as self-initiated therapy in patients with recurrent genital herpes.


Cost-effectiveness model of cytomegalovirus management strategies in renal transplantation. Comparing valAcyclovir / Aciclovir prophylaxis with current practice.

BACKGROUND: Cytomegalovirus (CMV) disease may occur following renal transplantation and has been shown to have health and cost consequences in this setting. OBJECTIVE: To compare the cost effectiveness of different CMV management strategies for renal transplant patients: prophylaxis with (i) oral valAcyclovir / Aciclovir or (ii) intravenous ganciclovir; viral testing for CMV followed by (iii) pre-emptive therapy with intravenous ganciclovir or (iv) adjustment of immunosuppression and intensive monitoring; or (v) waiting to treat when CMV disease develops. METHODS: A decision-tree model was constructed that included the different management strategies for the donor seropositive/recipient seronegative (D+R-) population. Clinical outcomes for the D+R- population came from clinical trials. Treatment algorithms and costs for CMV syndrome and tissue invasive disease were developed from published literature and UK physician interviews. One- and 2-way sensitivity analyses were performed. STUDY PERSPECTIVE: UK National Health Service. RESULTS: Prophylaxis with either oral valAcyclovir / Aciclovir or intravenous ganciclovir dominated (lower costs and fewer cases of CMV disease) the pre-emptive treatment and wait-and-treat strategies. The cost per patient was from 157 Pounds to 438 Pounds higher with oral valAcyclovir / Aciclovir prophylaxis compared with intravenous ganciclovir prophylaxis and the incremental cost per case of CMV disease avoided with valAcyclovir / Aciclovir prophylaxis ranged from 2243 Pounds to 8111 Pounds (1996 values). These results are sensitive to the efficacy of intravenous ganciclovir prophylaxis and CMV management costs. CONCLUSIONS: For D+R- renal transplant patients, prophylaxis is the dominant (more effective and less costly) management strategy compared with pre-emptive and wait-and-treat strategies. The cost per patient with oral valAcyclovir / Aciclovir prophylaxis compared with intravenous ganciclovir prophylaxis is slightly higher in our base case scenario, but may be lower under reasonable alternative assumptions.


A randomized, placebo-controlled comparison of oral Valacyclovir ( Valtrex ) and Acyclovir / Aciclovir in immunocompetent patients with recurrent genital herpes infections. The ValAcyclovir / Aciclovir International Study Group.

OBJECTIVE: To compare Valacyclovir ( Valtrex ) hydrochloride with Acyclovir / Aciclovir in the treatment of recurrent genital herpes infection. DESIGN: A multicenter, double-blind, placebo-controlled, randomized, parallel-design study. SETTING: University clinics (dermatology, gynecology, and infectious diseases) and private practices. PATIENTS: One thousand two hundred patients with recurrent genital herpes simplex infections. INTERVENTIONS: Patients self-initiated oral therapy with 1000 mg of Valacyclovir ( Valtrex ) hydrochloride twice daily, 200 mg of Acyclovir / Aciclovir 5 times daily, or placebo for 5 days. MAIN OUTCOME MEASURES: Resolution of all signs and symptoms of recurrent genital herpes infection. RESULTS: Both drugs were significantly more effective than placebo in speeding resolution of herpetic episodes (median duration, 4.8, 4.8, and 5.9 days, respectively); the hazards ratios for Valacyclovir ( Valtrex ) and Acyclovir / Aciclovir vs placebo were 1.66 (95% confidence interval [CI], 1.38-2.01) and 1.71 (95% CI, 1.41-2.06) (both P < .001). Similarly, Valacyclovir ( Valtrex ) and Acyclovir / Aciclovir significantly hastened lesion healing (hazards ratios vs placebo were 1.88 [95% CI, 1.53-2.32] and 1.90 [95% CI, 1.55-2.34], respectively; P < .001). Pain duration was shorter in Valacyclovir ( Valtrex )- and Acyclovir / Aciclovir-treated patients (median, 2 vs 3 days). Viral shedding stopped 2.55 times faster in patients treated with Valacyclovir ( Valtrex ) and 2.24 times faster in patients treated with Acyclovir / Aciclovir than in patients treated with placebo. Aborted episodes, in which lesions did not progress beyond the macule or papule stage, tended to occur in more patients treated with Valacyclovir ( Valtrex ) (25.9%) or Acyclovir / Aciclovir (24.8%) than in patients treated with placebo (19.8%). Valacyclovir ( Valtrex ) and Acyclovir / Aciclovir did not differ significantly with regard to their respective effects on any of the above efficacy parameters. The nature, severity, and frequency of adverse events did not differ among the 3 treatment groups. CONCLUSIONS: Twice-daily Valacyclovir ( Valtrex ) was as effective and well tolerated in the treatment of recurrent genital herpes simplex virus infection as 5-times-daily Acyclovir