Both acyclovir and valacyclovir are medications that are used to treat the viruses known as herpes simplex, varicella zoster, and herpes zoster. These viruses are responsible for certain diseases like chickenpox and shingles, and the drugs can help prevent them from replicating in the body. Despite the overt similarities between these drugs, they have important differences between them that may determine how and when they are used in a clinical setting. A major difference between acyclovir and valacyclovir pertains to their bioavailability, or how efficiently they are absorbed into the bloodstream after ingestion. Valacyclovir tends to be absorbed more slowly than acyclovir, regardless of whether it is administered as a topical solution, by mouth, or via intravenous (IV) means. These two drugs are also broken down by the body at different rates. Acyclovir is metabolized my quickly, meaning that it must be taken more frequently than valacyclovir. buy tretinoin cream 0.05 uk Valaciclovir, also spelled valacyclovir, is an antiviral drug used in the management of herpes simplex, herpes zoster (shingles), and herpes B. It is a prodrug, which is converted to aciclovir in a persons body. Common adverse drug reactions (≥1% of patients) associated with valaciclovir therapy are the same as for aciclovir, its active metabolite, and include: nausea, vomiting, diarrhea and headache. Infrequent adverse effects (0.1–1% of patients) include: agitation, vertigo, confusion, dizziness, edema, arthralgia, sore throat, constipation, abdominal pain, rash, weakness and/or renal impairment. Rare adverse effects ( Valaciclovir belongs to a family of molecules first described and patented by Paolo Cornaglia Ferraris in 1982 (patents EP0077460 A2, CA1258149A1, DE3273785D1, EP0077460A3, EP0077460B1, US4567182). Valaciclovir is a prodrug, an esterified version of aciclovir that has greater oral bioavailability (about 55%) than aciclovir (10–20%). It is converted by esterases to the active drug aciclovir, as well as the amino acid valine, via hepatic first-pass metabolism. Prednisone addiction Sertraline dosage range Though both acyclovir and valacyclovir are used to treat similar conditions, they differ in terms of bioavailability, the dosages. sildenafil pfizer Valaciclovir versus aciclovir in patient initiated treatment of recurrent genital herpes a randomised, double blind clinical trial. valacyclovir; Acyclovir. How to cite this article Rajalakshmi R, Kumari R, Thappa DM. Acyclovir versus valacyclovir. Indian J Dermatol Venereol Leprol 2010;9-44. In which they mention how toxicity secondary to starting new treatments in patients with renal failure can give rise to false diagnoses. One of the patients cited by the authors suffered from neurotoxicity due to acyclovir. Acyclovir and its ester, valacyclovir, are widely used in treating infection with the varicella zoster virus, and its Summary of Product Characteristicslists neurotoxicity as an extremely rare event. However, we have observed 3 episodes similar to that described by Quiñones et al in patients on haemodialysis receiving acyclovir-valacyclovir for metameric herpes zoster. Female patient aged 61 years treated with oral acyclovir at 800mg/12 hours. After the third dose, she experienced a psychotic reaction with visual hallucinations and dysarthria. Antiviral treatment was suspended and the psychiatric symptoms resolved completely in 3 days. Male patient aged 66 years undergoing treatment with oral valacyclovir (500mg/12 hours). After the second dose, he presented dysarthria and reduced consciousness. BACKGROUND Valacyclovir exhibits better oral absorption and higher, more prolonged serum concentrations than oral acyclovir. The efficacy of valacyclovir and acyclovir on genital herpes simplex virus (HSV) shedding was assessed in a double-blind, 3-period crossover trial. METHODS Sixty-nine immunocompetent participants with genital HSV-2 received oral valacyclovir, acyclovir, and matching placebo in random order for 7-week periods. Participants provided daily genital mucosal swabs for HSV… Valacyclovir acyclovir Acyclovir and valacyclovir neurotoxicity in patients with renal failure., Valaciclovir versus aciclovir in patient initiated. Generic for azithromycin Valacyclovir oral tablet is a prescription medication used to treat or prevent infections caused by the herpes simplex virus. These include cold sores. Valacyclovir Side Effects, Dosage, Uses, and More Acyclovir versus valacyclovir Rajalakshmi R, Kumari R, Thappa DM. Valacyclovir Oral Uses, Side Effects, Interactions, Pictures. The concentrations of acyclovir in serum and CSF were measured at steady state after 6 days of oral treatment with 1,000 mg of valacyclovir three times a day. buy retin a 0.025 Drug information on Valacyclovir Hydrochloride Caplet for health care professionals. BACKGROUND Valacyclovir exhibits better oral absorption and higher, more prolonged serum concentrations than oral acyclovir. The efficacy of valacyclovir.