Greatest experience in HSV treatment with this agent and only antiviral available in IV form. Data supports continuous use for suppression for up to 6 years without adverse effects or great risk of developing resistance (in normal hosts). Topical gel, 1% may be used if resistant genital HSV identified. One application per day x 5 days should be sufficient to permit lesion healing, decrease symptoms and viral shedding. The preparation must be made by a compounding pharmacy as it is not commercially available. Injectable use usually only considered for refractory acyclovir-resistant cases not responsive to foscarnet. Herpes Simplex Virus is a sample topic from the Johns Hopkins ABX Guide. ACV-TP competitively inhibits viral DNA polymerase, incorporates into and terminates the growing viral DNA chain, and inactivates of the viral DNA polymerase. Valacyclovir is converted to acyclovir, which is converted to its triphosphate form, acyclovir triphosphate (ACV-TP). The primary mechanism of resistance to valacyclovir is related to viral thymidine kinase and DNA polymerase mutations. No relationship has been established between the effective in vitro and in vivo concentrations of valacyclovir. Valacyclovir is well absorbed via intestinal brush border membranes and undergoes rapid and extensive first-pass intestinal/hepatic metabolism by the enzyme valacyclovir hydrolase to acyclovir and L-valine. Table 2 Adverse effects include nausea, headache, vomiting, dizziness and abdominal pain. Oral: 500mg and 1g caplet HSV infections of skin and mucous membranes including initial and recurrent genital herpes Adult: Initial genital: 1 g po bid for 7 10 days Recurrent genital: 500 mg bid for 3 5 days or 1 g po qd x 5 days Pediatric: Safety and efficacy in pre-pubertal pediatric patients not established.
Some features of the Laboratory Test Directory may not be available; to take advantage of all features, please upgrade your browser. Remind me later Don't remind me again Patient Preparation: Instructions patient must follow before/during specimen collection. Storage/Transport Temperature: Preferred temperatures for storage prior to and during shipping to ARUP. Unacceptable Conditions: Common conditions under which a specimen will be rejected. Specimen Preparation: Instructions for specimen prep before/after collection and prior to transport. Remarks: Additional specimen collection, transport, or test submission information. Stability: Acceptable times/temperatures for specimens. Times include storage and transport time to ARUP." Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. This test was developed and its performance characteristics determined by ARUP Laboratories. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. A processing fee will be billed for isolates that fail to grow to 3-4 positivity as indicated in the specimen requirements. For specimens other than isolates (swabs) refer to Herpes Simplex Virus Culture (Test Number 0065005). , and the resulting acyclovir serum levels are much higher than those achieved with oral acyclovir. Pharmacokinetic studies reveal that a therapeutic drug level equivalent to acyclovir 800 mg five times daily can be achieved with 1000 mg valacyclovir given every 8 hours . Because of the improved bioavailability of valacyclovir compared with acyclovir, studies have evaluated less frequent dosing for patients with HSV infection. Valacyclovir is effective in the treatment of first-episode HSV infection at a dose of 500–1000 mg to twice daily, and in the treatment of recurrent HSV infection at a dose of 500 mg twice daily if initiated within the first 24 h of signs or symptoms. Therapy should be continued until all lesions are dry and crusted. Additionally, valacyclovir is effective as suppressive therapy at a dose of 250 mg twice daily, 500 mg once daily (for patients with fewer than 10 recurrences per year), and 1 g once daily (for patients with 10 or more recurrences per year) [). A study evaluating very high valacyclovir dosing (8 g/day) for suppression of CMV in patients with advanced HIV disease suggested a possible association between valacyclovir and the syndromes of thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome (TTP/HUS).
Cold Sores Herpes Labialis VALTREX® valacyclovir hydrochloride Caplets. The possibility of viral resistance to valacyclovir and therefore, to acyclovir. Antiviral Susceptibility, Herpes Simplex Virus, Acyclovir. 2010866. Ordering Recommendation. Detect herpes simplex virus HSV resistance to acyclovir.