Brivudine (trade names Zostex, Mevir, Brivir, among others) is an antiviral drug used in the treatment of herpes zoster ("shingles"). Like other antivirals, it acts by inhibiting replication of the target virus.

Brivudine
Brivudine - Brivudin.svg
Clinical data
Trade namesZostex, Mevir, Brivir, many others
Other namesBVDU
AHFS/Drugs.comInternational Drug Names
Pregnancy
category
  • Contraindicated
Routes of
administration
Oral
ATC code
Legal status
Legal status
  • In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability30%
Protein binding>95%
MetabolismThymidine phosphorylase
MetabolitesBromovinyluracil
Elimination half-life16 hours
Excretion65% renal (mainly metabolites), 20% faeces
Identifiers
  • 5-[(E)-2-bromoethenyl]-1-[(2R,4S,5R)-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,2,3,4-tetrahydropyrimidine-2,4-dione
CAS Number
PubChem CID
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC11H13BrN2O5
Molar mass333.138 g·mol−1
3D model (JSmol)
Specific rotation+9°±1°
Density1.86 g/cm3
Melting point165 to 166 °C (329 to 331 °F) (decomposes)
  • Br[C@H]=CC=1C(=O)NC(=O)N(C=1)[C@@H]2O[C@@H]([C@@H](O)C2)CO
  • InChI=1S/C11H13BrN2O5/c12-2-1-6-4-14(11(18)13-10(6)17)9-3-7(16)8(5-15)19-9/h1-2,4,7-9,15-16H,3,5H2,(H,13,17,18)/b2-1+/t7-,8+,9+/m0/s1 checkY
  • Key:ODZBBRURCPAEIQ-PIXDULNESA-N checkY
 ☒NcheckY (what is this?)  (verify)

Medical usesEdit

Brivudine is used for the treatment of herpes zoster in adult patients. It is taken orally once daily, in contrast to aciclovir, valaciclovir and other antivirals.[1] A study has found that it is more effective than aciclovir, but this has been disputed because of a possible conflict of interest on part of the study authors.[2]

ContraindicationsEdit

The drug is contraindicated in patients undergoing immunosuppression (for example because of an organ transplant) or cancer therapy, especially with fluorouracil (5-FU) and chemically related (pro)drugs such as capecitabine and tegafur, as well as the antimycotic drug flucytosine, which is also related to 5-FU. It has not been proven to be safe in children and pregnant or breastfeeding women.[1]

Adverse effectsEdit

The drug is generally well tolerated. The only common side effect is nausea (in 2% of patients). Less common side effects (<1%) include headache, increased or lowered blood cell counts (granulocytopenia, anaemia, lymphocytosis, monocytosis), increased liver enzymes, and allergic reactions.[1]

InteractionsEdit

Brivudine interacts strongly and in rare cases lethally with the anticancer drug fluorouracil (5-FU), its prodrugs and related substances. Even topically applied 5-FU can be dangerous in combination with brivudine. This is caused by the main metabolite, bromovinyluracil (BVU), irreversibly inhibiting the enzyme dihydropyrimidine dehydrogenase (DPD) which is necessary for inactivating 5-FU. After a standard brivudine therapy, DPD function can be compromised for up to 18 days. This interaction is shared with the closely related drug sorivudine which also has BVU as its main metabolite.[1][3]

There are no other relevant interactions. Brivudine does not significantly influence the cytochrome P450 enzymes in the liver.[1]

PharmacologyEdit

Spectrum of activityEdit

The drug inhibits replication of varicella zoster virus (VZV) – which causes herpes zoster – and herpes simplex virus type 1 (HSV-1), but not HSV-2 which typically causes genital herpes. In vitro, inhibitory concentrations against VZV are 200- to 1000-fold lower than those of aciclovir and penciclovir, theoretically indicating a much higher potency of brivudine. Clinically relevant VZV strains are particularly sensitive.[4]

Mechanism of actionEdit

Brivudine is an analogue of the nucleoside thymidine. The active compound is brivudine 5'-triphosphate, which is formed in subsequent phosphorylations by viral (but not human) thymidine kinase and presumably by nucleoside-diphosphate kinase. Brivudine 5'-triphosphate works because it is incorporated into the viral DNA, but then blocks the action of DNA polymerases, thus inhibiting viral replication.[1][4]

PharmacokineticsEdit

Brivudine is well and rapidly absorbed from the gut and undergoes first-pass metabolism in the liver, where the enzyme thymidine phosphorylase[5] quickly splits off the sugar component, leading to a bioavailability of 30%. The resulting metabolite is bromovinyluracil (BVU), which does not have antiviral activity. BVU is also the only metabolite that can be detected in the blood plasma.[1][6]

Highest blood plasma concentrations are reached after one hour. Brivudine is almost completely (>95%) bound to plasma proteins. Terminal half-life is 16 hours; 65% of the substance are found in the urine and 20% in the faeces, mainly in form of an acetic acid derivative (which is not detectable in the plasma), but also other water-soluble metabolites, which are urea derivatives. Less than 1% is excreted in form of the original compound.[1]

ChemistryEdit

The molecule has three chiral carbon atoms in the deoxyribose (sugar) part all of which have defined orientation; i.e. the drug is stereochemically pure.[1] The substance is a white powder.

ManufacturingEdit

Main supplier is Berlin Chemie, now part of Italy's Menarini Group. In Central America is provided by Menarini Centro America and Wyeth.[citation needed]

HistoryEdit

The substance was first synthesized by scientists at the University of Birmingham in the UK in 1976. It was shown to be a potent inhibitor of HSV-1 and VZV by Erik De Clercq at the Rega Institute for Medical Research in Belgium in 1979. In the 1980s the drug became commercially available in East Germany, where it was marketed as Helpin by a pharmaceutical company called Berlin-Chemie. Only after the indication was changed to the treatment of herpes zoster in 2001 did it become more widely available in Europe.[7][8]

Brivudine is approved for use in a number of European countries including Austria, Belgium, Germany, Greece, Italy, Portugal, Spain and Switzerland.[9]

EtymologyEdit

The name brivudine derives from the chemical nomenclature bromo-vinyl-deoxyuridine or BVDU for short. It is sold under trade names such as Bridic, Brival, Brivex, Brivir, Brivirac, Brivox, Brivuzost, Zerpex, Zonavir, Zostex, and Zovudex.[9]

ResearchEdit

A Cochrane Systematic Review examined the effectiveness of multiple antiviral drugs in the treatment of herpes simplex virus epithelial keratitis. Brivudine was found to be significantly more effective than idoxuridine in increasing the number of successfully healed eyes of participants.[10]

See alsoEdit

Related antiviral drugs

Vaccines and other treatments

  • Zostavax, a live virus Herpes zoster (shingles) vaccine
  • Varivax, a live virus Varicella Zoster (chickenpox) vaccine
  • Shingrix, a recombinant subunit vaccine for shingles
  • VZV immune globulin, an antibody-based treatment for immune-suppressed patients with zoster

ReferencesEdit

  1. ^ a b c d e f g h i Jasek W, ed. (2007). Austria-Codex (in German) (62nd ed.). Vienna: Österreichischer Apothekerverlag. pp. 5246–8. ISBN 978-3-85200-181-4.
  2. ^ "Brivudin (Zostex) besser als Aciclovir (Zovirax a.a.)?". Arznei-telegramm (in German). 5/2007.
  3. ^ "UAW – Aus Fehlern lernen - Potenziell tödlich verlaufende Wechselwirkung zwischen Brivudin (Zostex) und 5-Fluoropyrimidinen" (PDF). Deutsches Ärzteblatt (in German). 103 (27). 7 July 2006.
  4. ^ a b Steinhilber D, Schubert-Zsilavecz M, Roth HJ (2005). Medizinische Chemie (in German). Stuttgart: Deutscher Apotheker Verlag. pp. 581–2. ISBN 3-7692-3483-9.
  5. ^ Desgranges C, Razaka G, Rabaud M, Bricaud H, Balzarini J, De Clercq E (December 1983). "Phosphorolysis of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) and other 5-substituted-2'-deoxyuridines by purified human thymidine phosphorylase and intact blood platelets". Biochemical Pharmacology. 32 (23): 3583–90. doi:10.1016/0006-2952(83)90307-6. PMID 6651877.
  6. ^ Mutschler E, Schäfer-Korting M (2001). Arzneimittelwirkungen (in German) (8 ed.). Stuttgart: Wissenschaftliche Verlagsgesellschaft. p. 847. ISBN 3-8047-1763-2.
  7. ^ De Clercq E (December 2004). "Discovery and development of BVDU (brivudin) as a therapeutic for the treatment of herpes zoster". Biochemical Pharmacology. 68 (12): 2301–15. doi:10.1016/j.bcp.2004.07.039. PMID 15548377.
  8. ^ Tringali C, ed. (2012). Bioactive Compounds from Natural Sources (2nd ed.). CRC Press. p. 170.
  9. ^ a b International Drug Names: Brivudine.
  10. ^ Wilhelmus KR (January 2015). "Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis". The Cochrane Database of Systematic Reviews. 1: CD002898. doi:10.1002/14651858.CD002898.pub5. PMC 4443501. PMID 25879115.