Valtrex

Valaciclovir

Clinical data
Trade names	Valtrex
AHFS/Drugs.com	Monograph
MedlinePlus	a695010
License data	US FDA: Valacyclovir
Pregnancy category	AU: B3 US: B (No risk in non-human studies)
Routes of administration	Oral
ATC code	J05AB11 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) UK: POM (Prescription only) US: ℞-only In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability	55%
Protein binding	13–18%
Metabolism	Hepatic (to aciclovir)
Biological half-life	<30 minutes (valaciclovir); 2.5–3.6 hours (aciclovir)
Excretion	Renal 40–50% (aciclovir), faecal 47% (aciclovir)
Identifiers
IUPAC name (S)-2-[(2-amino-6-oxo-6,9-dihydro-3H-purin-9-yl)methoxy]ethyl-2-amino-3-methylbutanoate
CAS Number	124832-26-4 N
PubChem CID	60773
IUPHAR/BPS	4824
DrugBank	DB00577 Y
ChemSpider	54770 Y
UNII	MZ1IW7Q79D
KEGG	D00398 N
ChEBI	CHEBI:35854 Y
ChEMBL	CHEMBL1349 Y
NIAID ChemDB	070982
ECHA InfoCard	100.114.479
Chemical and physical data
Formula	C13H20N6O4
Molar mass	324.336 g/mol
3D model (Jmol)	Interactive image
SMILES O=C(OCCOCn1c2N\C(=N/C(=O)c2nc1)N)[C@@H](N)C(C)C
InChI 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 Y Key:HDOVUKNUBWVHOX-QMMMGPOBSA-N Y
NY (what is this?)

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, being converted in vivo to aciclovir.

Valaciclovir was approved for medical use in 1995. It is marketed by GlaxoSmithKline under the trade names Valtrex and Zelitrex. Valaciclovir has been available as a generic drug in the U.S. since November 25, 2009.

Valaciclovir is indicated for the treatment of HSV and VZV infections, including:

It has shown promise as a treatment for infectious mononucleosis, and is preventively administered in suspected cases of herpes B virus exposure.

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 (<0.1% of patients) include: coma, seizures, neutropenia, leukopenia, tremor, ataxia, encephalopathy, psychotic symptoms, crystalluria, anorexia, fatigue, hepatitis, Stevens–Johnson syndrome, toxic epidermal necrolysis and/or anaphylaxis.