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In some countries, this medicine may only be approved for veterinary use.



ATC (Anatomical Therapeutic Chemical Classification)


CAS registry number (Chemical Abstracts Service)


Chemical Formula


Molecular Weight


Therapeutic Categories

Antithyroid agent

Imidazole derivative

Chemical Names

1-Metyl-1,3-dihydro-2H-imidazole-2-tione (Ph. Eur.)

1-Metyl-2-mercaptoimidazole (WHO)

1-Metylimidazole-2-tiol (BAN)

2H-Imidazole-2-tione, 1,3-dihydro-1-metyl- (USAN)

Foreign Names

  • Thiamazolum (Latin)
  • Thiamazol (German)
  • Thiamazol (French)
  • Tiamazol (Spanish)

Generic Names

  • Thiamazole (OS: BAN, JAN, DCF)
  • Tiamazolo (OS: DCIT)
  • Mercazolyl (IS)
  • Methimazole (IS)
  • Methylmercaptoimidazole (IS)
  • Methymazole (IS)
  • NSC 38608 (IS)
  • UNII-554Z48XN5E (IS)
  • Methimazole (PH: USP 38)
  • Metimazolo (PH: F.U. IX)
  • Thiamazole (PH: BP 2016, JP XVI, Ph. Eur. 8)
  • Thiamazolum (PH: Ph. Eur. 8)

Brand Names

  • Apo-Methimazole
    Apotex, Canada
  • Athyrazol
    Jadran, Bosnia & Herzegowina; Providens, Croatia (Hrvatska)
  • Based
    Panion & BF, Taiwan
  • Bromazolo (Thiamazole and Dibromotyrosine)
    Baldacci, Italy
  • Favistan
    Bosnalijek, Bosnia & Herzegowina; LENIS, Slovenia; Temmler, Germany
  • Felidale (veterinary use)
    Dechra, Netherlands; Dechra Veterinary Products, United Kingdom; Selecta, Germany
  • Felimazole (veterinary use)
    Albrecht, Germany; Dechra, Austria; Dechra, Finland; Dechra, Ireland; Dechra, Netherlands; Dechra, Norway; Dechra, Sweden; Dechra Veterinary Products, Belgium; Dechra Veterinary Products, France; Dechra Veterinary Products, United Kingdom; Dermcare-Vet, Australia; MSD Animal Health, Switzerland
  • Ganglioside
    Armstrong Laboratorios de Mexico, Mexico
  • Hontan
    Ying Yuan, Taiwan
  • Hyper-T (veterinary use)
    Bayer New Zealand, New Zealand
  • Jia Qi Ya
    Qilu, China
  • Lica
    Swiss Pharm, Taiwan
  • Mercaptizol
    Taro, Israel
  • Mercazole
    Chugai Pharmaceutical, Japan
  • Mercazolyl-Zdorovye
    Zdorovie, Georgia
  • Methimazole Johnson
    Johnson, Taiwan
  • Methimazole Par
    Par Pharmaceutical, Inc., United States
  • Methimazole Yung Shin
    Yung Shin, Thailand
  • Methizol
    Update, Taiwan
  • Methizol SD
    mibe, Germany
  • Metibasol
    Sanóbia, Portugal
  • Metizol
    ICN, Bulgaria; PharmaSwiss, Poland; SIA Meda Pharma, Lithuania
  • Metothyrin
    PannonPharma, Hungary
  • Northyx
    Centrix Pharmaceutical, United States
  • Strumazol
    Aspen, Netherlands; Euro Registratie, Netherlands; Medcor, Netherlands; Organon, Netherlands; Organon, Philippines; Takeda, Belgium
  • Tab-Zole
    Swiss Export, Lebanon
  • Tapazol
    Biolabfarma, Brazil; Grupo Farma, Colombia; Grupo Farma, Ecuador; Siegfried, Mexico; Cipa, Peru
  • Tapazole
    A. Menarini, Philippines; DKSH, Thailand; Monarch, United States; Paladin, Canada; Pharmaline, Lebanon; Teofarma, Italy
  • Tapdin
    MedChoice, Philippines
  • Teysuno (Thiamazole and Tegafur, + Gimeracil)
    Nordic Pharma, Slovakia
  • Thacapzol
    Recip, Sweden
  • Thiafeline (veterinary use)
    AST, Netherlands; Laboratoire TVM, France; Le Vet, Austria; Le Vet Beheer, Ireland; Le Vet Pharma B.V., United Kingdom; Vetcare, Finland
  • Thiafeline chats (veterinary use)
    Le Vet, Belgium
  • Thiamatab (veterinary use)
    CPPharma, Germany
  • Thiamazol Aristo
    Aristo Pharma, Germany
  • Thiamazol Henning
    Henning Berlin, Germany
  • Thiamazol HEXAL
    Hexal, Germany
  • Thiamazol Lindopharm
    Aristo Pharma, Germany
  • Thiamazol Sandoz
    Sandoz, Austria
  • Thiamazole Merck
    Merck, Lithuania
  • Thimazol
    Shun Hwa, Taiwan
  • Thycapzol
    Sandoz, Denmark
  • Thyromazol
    Abdi Ibrahim, Turkey
  • Thyrozol
    Merck, Chile; Merck, Czech Republic; Merck, Estonia; Merck, Indonesia; Merck, Lithuania; Merck, Poland; Merck, Romania; Merck, Serbia; Merck, Slovakia; Merck KGaA, Latvia; Merck KGaA, Vietnam; Merck Serono, China; Merck Serono, Germany; Merck Serono, France; Merck Serono, Russian Federation; Merck Sharp & Dohme, Bosnia & Herzegowina; Serono, Tunisia; Merck, Peru
  • Tiastat
    Bosnalijek, Serbia
  • Timazol
    Sriprasit Pharma, Thailand
  • Tirodril
    Estedi, Spain
  • Tirozol
    Merck, Georgia


BANBritish Approved Name
DCFDénomination Commune Française
DCITDenominazione Comune Italiana
ISInofficial Synonym
JANJapanese Accepted Name
OSOfficial Synonym
PHPharmacopoeia Name
Ph. Eur.European Pharmacopoeia
Rec.INNRecommended International Nonproprietary Name (World Health Organization)
USANUnited States Adopted Name
WHOWorld Health Organization

Further information on drug naming conventions: International Nonproprietary Names.

Important Notice: The international database is in BETA release. This means it is still under development and may contain inaccuracies. It is not intended as a substitute for the expertise and judgement of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that the use of any medication in any country is safe, appropriate or effective for you. Consult with your healthcare professional before taking any medication.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.