Zonisamide, sold under the brand name Zonegran among others, is a medication used to treat the symptoms of epilepsy and Parkinsons disease. Chemically it is a sulfonamide. It serves as an anticonvulsant used primarily as an adjunctive therapy in adults with Parkinsons disease, partial-onset seizures; infantile spasm, mixed seizure types of Lennox–Gastaut syndrome, myoclonic and generalized tonic clonic seizure. Despite this it is also sometimes used as a monotherapy for partial-onset seizures. Medical uses
Epilepsy
Zonisamide is approved in the United States, and United Kingdom for adjunctive treatment of partial seizures in adults and Japan for both adjunctive and monotherapy for partial seizures (simple, complex, secondarily generalized), generalized (tonic, tonic-clonic (grand mal), and atypical absence) and combined seizures. In Australia it is marketed as both an adjunctive therapy and monotherapy for partial seizures only. Parkinsons disease
It has been approved for the treatment of the motor symptoms of Parkinsons disease (PD), as an adjunct to levodopa, in a few countries such as Japan. In Japan, zonisamide has been used as an adjunct to levodopa treatment since 2009. In addition, there is clinical evidence that zonisamide in combination with levodopa control of motor symptoms of PD but evidence for the treatment of the non motor symptoms of PD lacking. Adverse effects
Adverse effects by incidence:Very common (>10% incidence) adverse effects include:

Common (1-10% incidence) adverse effects include:

Interactions
Zonisamide and other carbonic anhydrase inhibitors such as topiramate, furosemide, and hydrochlorothiazide have been known to interfere with amobarbital, which has led to inadequate anesthetization during the Wada test.
In some cases, the presence or absence of sperm granulomas may determine the success rate for vasectomy reversal. It is believed that sperm granulomas may be protective because they can prevent the obstruction of the testicles and epididymis. Sperm granulomas are believed to reduce the pressure thats generated after vasectomy and prevent blockages of sperm output into the vas fluid during ejaculation. Therefore, there are no changes in the amount of sperm that are produced into the vas fluid. Sperm granulomas in animals
Additionally, sperm granulomas can exist in non-human species such as rats, dogs, horses, fish, etc. Non-human species exhibit the same causes for sperm granulomas, including infection, injury, and trauma to the epididymal region. For example, vasectomized rats were seen to also have high prevalence of sperm granulomas post-operation while general populations of rats experienced much lower prevalence of sperm granulomas. In the case of sperm granulomas within dogs, their presence is common amongst poorly performed vasectomies. This is consistent with the idea that these lesions form at the site where there is trauma or a chance for the sperm to leak outside of the vasa deferentia or epididymis. In multiple species, sperm granulomas have also been linked to the success rate of certain procedures such as vasectomy reversals, or vasovasostomy. There is also an association between sperm granuloma and antibodies produced against sperm antigens.