The median time to cessation of pain was about 3 days in both treatment groups.Two clinical trials were conducted, one in immunocompetent adults and one in HIV-1−infected adults.A double-blind, 12-month, placebo-and active-controlled trial enrolled immunocompetent adults with a history of 6 or more recurrences per year. The only adverse reaction reported in greater than 10% of pediatric subjects aged less than 18 years was headache.Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.In clinical trials for the treatment of cold sores, the adverse reactions reported by subjects receiving VALTREX 2 grams twice daily (n = 609) or placebo (n = 609) for 1 day, respectively, included headache (14%, 10%) and dizziness (2%, 1%). Subjects self-initiated therapy at the earliest symptoms and prior to any signs of a cold sore. A primary herpes occurrence during the first trimester of pregnancy has been associated with neonatal chorioretinitis, microcephaly, and, in rare cases, skin lesions. Treatment with VALTREX should be stopped immediately if clinical signs, symptoms, and laboratory abnormalities consistent with TTP/HUS occur.Cases of acute renal failure have been reported in:In the event of acute renal failure and anuria, the patient may benefit from hemodialysis until renal function is restored [see Central nervous system adverse reactions, including agitation, hallucinations, confusion, delirium, seizures, and encephalopathy, have been reported in both adult and pediatric patients with or without reduced renal function and in patients with underlying renal disease who received higher-than-recommended doses of VALTREX for their level of renal function. In biochemical assays, acyclovir triphosphate inhibits replication of α-herpes viral DNA. In a clinical trial of herpes zoster, the duration of pain after healing (postherpetic neuralgia) was longer in subjects 65 and older compared with younger adults. about VALTREX that is written for health professionals. Frameshifts were commonly isolated and result in premature truncation of the HSV TK product with consequent decreased susceptibility to acyclovir. In the presence of metabolic activation (76% to 88% conversion to acyclovir), valacyclovir was mutagenic.Valacyclovir was mutagenic in a mouse micronucleus assay.Valacyclovir did not impair fertility or reproduction in male or female rats at acyclovir exposures (AUC) 6 times higher than in humans given the MRHD. Genital herpes is frequently transmitted in the absence of symptoms through asymptomatic viral shedding. Extreme temperatures can have a big effect on both prescription and over-the-counter drugs. All rights reserved. tests that measure how well the liver and kidneys work.The most common side effect seen in children aged less It is used to treat a viral infection affecting the skin known as shingles (herpes zoster). Acyclovir accounted for 89% of the radioactivity excreted in the urine. Patients should be instructed that treatment for cold sores should not exceed 1 day (2 doses) and that their doses should be taken about 12 hours apart. The efficacy of treatment with VALTREX when initiated more than 72 hours after the onset of signs and symptoms has not been established.VALTREX is indicated for treatment of recurrent episodes of genital herpes in immunocompetent adults. If you would like more information, talk with your healthcare Copyright © 1995-2020 Psych Central. Ask your If you have questions about your medicines, talk to your health care provider.Valacyclovir comes as a tablet to take by mouth. Results supporting efficacy were replicated in a second trial.In a third trial, subjects were randomized to receive VALTREX 500 mg twice daily for 5 days (n = 398) or VALTREX 500 mg twice daily for 3 days (and matching placebo twice daily for 2 additional days) (n = 402). These events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to VALTREX.Acute hypersensitivity reactions including anaphylaxis, angioedema, dyspnea, pruritus, rash, and urticaria [see Aggressive behavior; agitation; ataxia; coma; confusion; decreased consciousness; dysarthria; encephalopathy; mania; and psychosis, including auditory and visual hallucinations, seizures, tremors [see Renal failure, renal pain (may be associated with renal failure) [see Thrombocytopenia, aplastic anemia, leukocytoclastic vasculitis, TTP/HUS [see Erythema multiforme, rashes including photosensitivity, alopecia.No clinically significant drug-drug or drug-food interactions with VALTREX are known [see TTP/HUS, in some cases resulting in death, has occurred in patients with advanced HIV-1 disease and also in allogeneic bone marrow transplant and renal transplant recipients participating in clinical trials of VALTREX at doses of 8 grams per day. Valacyclovir hydrochloride is rapidly converted to acyclovir, which has demonstrated antiviral activity against HSV types 1 (HSV-1) and 2 (HSV-2) and VZV both in cell culture and Acyclovir is a synthetic purine deoxynucleoside that is phosphorylated intracellularly by the viral encoded thymidine kinase (TK; pUL23) of HSV or VZV into acyclovir monophosphate, a nucleotide analogue.