Valacyclovir  is the hydrochloride salt of the L-valyl ester (essential amino acid) of the antiviral drug acyclovir, basically an esterified version of acyclovir. 

Take only under medical supervision

It appears as a whitish crystalline powder soluble in water, methanol.

What it is used for and where

Medical

Dopo l'assunzione orale è convertito in acioclovir nel fegato e nel tratto intestinale di primo passaggio in adulti sani E' stato formulato per fornire una maggiore biodisponibilità orale di aciclovir. 

It is prescribed for herpes simplex infections and varicella zoster infections (1) and is considered a promising adjunct agent in pain control with acute apical abscesses (2). This study suggests that valacyclovir, together with levetiracetam, may have an anticonvulsant effect in patients with epilepsy (3). 

Like all drugs it can cause side effects. Always ask the physician.

For more information:   Valacyclovir studies

• Molecular Formula  C₁₃H₂₀N₆O₄
• Molecular Weight     324.34
• Exact Mass    324.154602
• CAS  124832-27-5
• UNII    MZ1IW7Q79D
• EC Number   603-015-6
• DSSTox Substance ID  DTXSID1023732
• IUPAC 2-[(2-amino-6-oxo-1H-purin-9-yl)methoxy]ethyl (2S)-2-amino-3-methylbutanoate
• InChI=1S/C13H20N6O4/c1-7(2)8(14)12(21)23-4-3-22-6-19-5-16-9-10(19)17-13(15)18-11(9)20/h5,7-8H,3-4,6,14H2,1-2H3,(H3,15,17,18,20)/t8-/m0/s1
• InChl Key      HDOVUKNUBWVHOX-QMMMGPOBSA-N
• SMILES   CC(C)C(C(=O)OCCOCN1C=NC2=C1N=C(NC2=O)N)N
• MDL number  MFCD01861507
• PubChem Substance ID    329823501
• ChEBI  35854
• RXCUI 73645    
• NCI   C28235

Synonyms

• Valacyclovir hydrochloride
• 2-{[(2-amino-6-oxo-1,6-dihydro-9H-purin-9-yl)methyl]oxy}ethyl L-valinate
• Valtrex
• L-valine, 2-[(2-amino-6-hydroxy-9H-purin-9-yl)methoxy]ethyl ester
• 2-[2-amino-1, 6-dihydro-6-oxo-9H-purin-9-yl-methoxy] ethyl valinate hydrochloride

References______________________________________________________________________

(1) Rajalakshmi R, Kumari R, Thappa DM. Acyclovir versus valacyclovir. Indian J Dermatol Venereol Leprol. 2010 Jul-Aug;76(4):439-44. doi: 10.4103/0378-6323.66577.

(2) Sabeti M, Zhong J, Hildebrandt K, Slots J. Valacyclovir in Pain Management of Acute Apical Abscesses: A Randomized Placebo-Controlled Double-Blind Pilot Study. J Endod. 2021 Nov;47(11):1724-1728. doi: 10.1016/j.joen.2021.07.001.

(3) Takahashi S, Takechi K, Jozukuri N, Niimura T, Chuma M, Goda M, Zamami Y, Izawa-Ishizawa Y, Imanishi M, Horinouchi Y, Ikeda Y, Tsuchiya K, Yanagawa H, Ishizawa K. Examination of the antiepileptic effects of valacyclovir using kindling mice- search for novel antiepileptic agents by drug repositioning using a large medical information database. Eur J Pharmacol. 2021 Jul 5;902:174099. doi: 10.1016/j.ejphar.2021.174099.