Products
Topiramate is commercially available in tablet and capsule form (Topamax, generic). It has been approved in many countries and in the United States since 1996.
Structure and properties
Topiramate (C12H21NO8S, Mr = 339.36 g/mol) lies as a white powder with a bitter taste that is soluble in water. It is a sulfamate-substituted monosaccharide.
Effects
Topiramate (ATC N03AX11) has antiepileptic (anticonvulsant), depressant, and appetite suppressant properties. The effects are attributed to the following mechanisms:
- Blockade of voltage-gated sodium channels.
- Blockade of voltage-gated calcium channels
- Enhancement of GABA activity at the GABA-A receptor.
- Antagonism at the AMPA receptor (belongs to the glutamate receptors).
- Inhibition of carbonic anhydrase II and IV.
Half-life is approximately 21 hours.
Indications
Dosage
According to the drug label. The dose is adjusted individually and gradually. Medicines are taken independently of meals and usually twice daily (morning and evening). Discontinuation should be gradual.
Contraindications
- Hypersensitivity
- Pregnancy: topiramate has fertility-damaging (teratogenic) properties.
- Women of childbearing age who are not using a safe method of contraception.
Full details of precautions and interactions can be found in the drug label.
Interactions
Topiramate is excreted predominantly, approximately 70%, unchanged. Metabolites are formed by hydroxylation, hydrolysis, and glucuronidation. Topiramate is reabsorbed at the kidney.
Adverse effects
The most common possible adverse effects include:
