Although
zonisamide was previously only used to treat
epilepsy, recently more applications have been forthcoming. Due to a good side effect profile, a lower frequency of interactions and a more comfortable posology, there are several studies regarding its uses in other pathologies such as
migraine,
neuropathic pain,
essential tremor and various
psychiatric diseases. A multicentered, randomized, double-blind, placebo-controlled study conducted in Japan suggested that
zonisamide, as an add-on treatment, has efficacy in treating motor symptoms in patients with
Parkinson's disease. In addition, other studies support the utility of
zonisamide in other symptoms of this disease. The therapeutic doses of
zonisamide for the treatment of
Parkinson's disease are considerably lower than those for the treatment of
epilepsy. This
antiepileptic drug has been used in Japan for more than 15 years and so it is expected that it will be safe and well tolerated in patients with
Parkinson's disease. However, the pharmacological mechanisms of the antiparkinsonian actions of
zonisamide remain unclear and more basic investigation is warranted. The aim of this paper is to review the structure, mechanisms of action, pharmacokinetics and antiparkinsonian action of
zonisamide.